Sample records for san andreas fault

  1. The San Andreas Fault 'Supersite' (Invited) (United States)

    Hudnut, K. W.


    An expanded and permanent Supersite has been proposed to the Committee on Earth Observation Satellites (CEOS) for the San Andreas Fault system, based upon the successful initial Group on Earth Observations (GEO) Geohazard Supersite for the Los Angeles region from 2009-2013. As justification for the comprehensive San Andreas Supersite, consider the earthquake history of California, in particular the devastating M 7.8 San Francisco earthquake of 1906, which occurred along the San Andreas Fault, as did an earthquake of similar magnitude in 1857 in southern California. Los Angeles was only a small town then, but now the risk exposure has increased for both of California's megacities. Between the San Francisco and Los Angeles urban areas lies a section of the San Andreas Fault known to creep continually, so it has relatively less earthquake hazard. It used to be thought of as capable of stopping earthquakes entering it from either direction. Transitional behavior at either end of the creeping section is known to display a full range of seismic to aseismic slip events and accompanying seismicity and strain transient events. Because the occurrence of creep events is well documented by instrumental networks such as CISN and PBO, the San Andreas Supersite can be expected to be especially effective. A good baseline level of geodetic data regarding past events and strain accumulation and release exists. Many prior publications regarding the occurrence of geophysical phenomena along the San Andreas Fault system mean that in order to make novel contributions, state-of-the-art science will be required within this Supersite region. In more recent years, the 1989 Loma Prieta earthquake struck adjacent to the San Andreas Fault and caused the most damage along the western side of the San Francisco Bay Area. More recently, the concern has focused on the potential for future events along the Hayward Fault along the eastern side of San Francisco Bay. In Southern California, earthquakes

  2. Synthetic seismicity for the San Andreas fault

    Directory of Open Access Journals (Sweden)

    S. N. Ward


    Full Text Available Because historical catalogs generally span only a few repetition intervals of major earthquakes, they do not provide much constraint on how regularly earthquakes recur. In order to obtain better recurrence statistics and long-term probability estimates for events M ? 6 on the San Andreas fault, we apply a seismicity model to this fault. The model is based on the concept of fault segmentation and the physics of static dislocations which allow for stress transfer between segments. Constraints are provided by geological and seismological observations of segment lengths, characteristic magnitudes and long-term slip rates. Segment parameters slightly modified from the Working Group on California Earthquake Probabilities allow us to reproduce observed seismicity over four orders of magnitude. The model yields quite irregular earthquake recurrence patterns. Only the largest events (M ? 7.5 are quasi-periodic; small events cluster. Both the average recurrence time and the aperiodicity are also a function of position along the fault. The model results are consistent with paleoseismic data for the San Andreas fault as well as a global set of historical and paleoseismic recurrence data. Thus irregular earthquake recurrence resulting from segment interaction is consistent with a large range of observations.

  3. San Andreas Fault in the Carrizo Plain (United States)


    The 1,200-kilometer (800-mile)San Andreas is the longest fault in California and one of the longest in North America. This perspective view of a portion of the fault was generated using data from the Shuttle Radar Topography Mission (SRTM), which flew on NASA's Space Shuttle last February, and an enhanced, true-color Landsat satellite image. The view shown looks southeast along the San Andreas where it cuts along the base of the mountains in the Temblor Range near Bakersfield. The fault is the distinctively linear feature to the right of the mountains. To the left of the range is a portion of the agriculturally rich San Joaquin Valley. In the background is the snow-capped peak of Mt. Pinos at an elevation of 2,692 meters (8,831 feet). The complex topography in the area is some of the most spectacular along the course of the fault. To the right of the fault is the famous Carrizo Plain. Dry conditions on the plain have helped preserve the surface trace of the fault, which is scrutinized by both amateur and professional geologists. In 1857, one of the largest earthquakes ever recorded in the United States occurred just north of the Carrizo Plain. With an estimated magnitude of 8.0, the quake severely shook buildings in Los Angeles, caused significant surface rupture along a 350-kilometer (220-mile) segment of the fault, and was felt as far away as Las Vegas, Nev. This portion of the San Andreas is an important area of study for seismologists. For visualization purposes, topographic heights displayed in this image are exaggerated two times.The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60

  4. San Andreas tremor cascades define deep fault zone complexity (United States)

    Shelly, David R.


    Weak seismic vibrations - tectonic tremor - can be used to delineate some plate boundary faults. Tremor on the deep San Andreas Fault, located at the boundary between the Pacific and North American plates, is thought to be a passive indicator of slow fault slip. San Andreas Fault tremor migrates at up to 30 m s-1, but the processes regulating tremor migration are unclear. Here I use a 12-year catalogue of more than 850,000 low-frequency earthquakes to systematically analyse the high-speed migration of tremor along the San Andreas Fault. I find that tremor migrates most effectively through regions of greatest tremor production and does not propagate through regions with gaps in tremor production. I interpret the rapid tremor migration as a self-regulating cascade of seismic ruptures along the fault, which implies that tremor may be an active, rather than passive participant in the slip propagation. I also identify an isolated group of tremor sources that are offset eastwards beneath the San Andreas Fault, possibly indicative of the interface between the Monterey Microplate, a hypothesized remnant of the subducted Farallon Plate, and the North American Plate. These observations illustrate a possible link between the central San Andreas Fault and tremor-producing subduction zones.

  5. San Andreas-sized Strike-slip Fault on Europa (United States)


    This mosaic of the south polar region of Jupiter's moon Europa shows the northern 290 kilometers (180 miles) of a strike-slip fault named Astypalaea Linea. The entire fault is about 810 kilometers (500 miles) long, about the size of the California portion of the San Andreas fault, which runs from the California-Mexico border north to the San Francisco Bay. In a strike-slip fault, two crustal blocks move horizontally past one another, similar to two opposing lanes of traffic. Overall motion along the fault seems to have followed a continuous narrow crack along the feature's entire length, with a path resembling steps on a staircase crossing zones that have been pulled apart. The images show that about 50 kilometers (30 miles) of displacement have taken place along the fault. The fault's opposite sides can be reconstructed like a puzzle, matching the shape of the sides and older, individual cracks and ridges broken by its movements. [figure removed for brevity, see original site] The red line marks the once active central crack of the fault. The black line outlines the fault zone, including material accumulated in the regions which have been pulled apart. Bends in the fault have allowed the surface to be pulled apart. This process created openings through which warmer, softer ice from below Europa's brittle ice shell surface, or frozen water from a possible subsurface ocean, could reach the surface. This upwelling of material formed large areas of new ice within the boundaries of the original fault. A similar pulling-apart phenomenon can be observed in the geological trough surrounding California's Salton Sea, in Death Valley and the Dead Sea. In those cases, the pulled-apart regions can include upwelled materials, but may be filled mostly by sedimentary and eroded material from above. One theory is that fault motion on Europa is induced by the pull of variable daily tides generated by Jupiter's gravitational tug on Europa. Tidal tension opens the fault and

  6. Structure of the San Andreas Fault at SAFOD (Invited) (United States)

    Chester, J. S.; Chester, F. M.; Sills, D. W.; Heron, B.; Almeida, R. V.; Guillemette, R. N.


    The San Andreas Fault Observatory at Depth (SAFOD) provides a unique opportunity to characterize the deformation of sedimentary and crystalline rocks subjected to variable loading rates and chemically reactive fluids at seismogenic depths along an active continental transform fault. The spot core captured relatively undeformed host rock, highly fractured and sheared rock from within the fault zone, and gouge from two prominent zones of aseismic creep, the Southwestern Deforming Zone (SDZ), and the Central Deforming Zone (CDZ). Distinct structural units sampled from west to east, include: (i) deformed crystalline rock west of the active zone, (ii) a fault-bordering damage zone composed of two distinct, highly fractured and cemented arkosic sandstones, (iii) a fault core associated with the SDZ composed of foliated cataclasites, gouge, and variably sheared siltstones and shales, (iv) deformed siltstones and shales within the central portion of the low velocity zone, and (v) the gouge associated with the CDZ. We have characterized the structure and syndeformation-alteration reactions of these units through detailed mapping at the mesoscopic and microscopic scales, XCT imaging, scanning electron microscopy, and elemental mapping. The San Andreas Fault zone at SAFOD is a broad zone of damage containing multiple fault-cores that juxtapose distinct structural-petrologc units. Multiple episodes of fracture, chemically-assisted comminution, neomineralization, and fault healing through cementation are evident. The SDZ and CDZ are composed of distinct 1-3 m-thick layers of incohesive, foliated fault gouge containing survior clasts up to 4 cm in diameter. Deformation of the gouge is relatively homogeneous at mesoscopic scale, occurring by slip along penetrative anastomosing polished shears that often occur at the boundaries of the survivor clasts. We suggest that 1) the extremely low frictional strength of the gouge reflects slip in shears containing a significant fraction of

  7. Fine-scale delineation of the location of and relative ground shaking within the San Andreas Fault zone at San Andreas Lake, San Mateo County, California (United States)

    Catchings, R.D.; Rymer, M.J.; Goldman, M.R.; Prentice, C.S.; Sickler, R.R.


    The San Francisco Public Utilities Commission is seismically retrofitting the water delivery system at San Andreas Lake, San Mateo County, California, where the reservoir intake system crosses the San Andreas Fault (SAF). The near-surface fault location and geometry are important considerations in the retrofit effort. Because the SAF trends through highly distorted Franciscan mélange and beneath much of the reservoir, the exact trace of the 1906 surface rupture is difficult to determine from surface mapping at San Andreas Lake. Based on surface mapping, it also is unclear if there are additional fault splays that extend northeast or southwest of the main surface rupture. To better understand the fault structure at San Andreas Lake, the U.S. Geological Survey acquired a series of seismic imaging profiles across the SAF at San Andreas Lake in 2008, 2009, and 2011, when the lake level was near historical lows and the surface traces of the SAF were exposed for the first time in decades. We used multiple seismic methods to locate the main 1906 rupture zone and fault splays within about 100 meters northeast of the main rupture zone. Our seismic observations are internally consistent, and our seismic indicators of faulting generally correlate with fault locations inferred from surface mapping. We also tested the accuracy of our seismic methods by comparing our seismically located faults with surface ruptures mapped by Schussler (1906) immediately after the April 18, 1906 San Francisco earthquake of approximate magnitude 7.9; our seismically determined fault locations were highly accurate. Near the reservoir intake facility at San Andreas Lake, our seismic data indicate the main 1906 surface rupture zone consists of at least three near-surface fault traces. Movement on multiple fault traces can have appreciable engineering significance because, unlike movement on a single strike-slip fault trace, differential movement on multiple fault traces may exert compressive and

  8. Viscoelastic coupling model of the San Andreas fault along the big bend, southern California (United States)

    Savage, J.C.; Lisowski, M.


    The big bend segment of the San Andreas fault is the 300-km-long segment in southern California that strikes about N65??W, roughly 25?? counterclockwise from the local tangent to the small circle about the Pacific-North America pole of rotation. The broad distribution of deformation of trilateration networks along this segment implies a locking depth of at least 25 km as interpreted by the conventional model of strain accumulation (continuous slip on the fault below the locking depth at the rate of relative plate motion), whereas the observed seismicity and laboratory data on fault strength suggest that the locking depth should be no greater than 10 to 15 km. The discrepancy is explained by the viscoelastic coupling model which accounts for the viscoelastic response of the lower crust. Thus the broad distribution of deformation observed across the big bend segment can be largely associated with the San Andreas fault itself, not subsidiary faults distributed throughout the region. The Working Group on California Earthquake Probabilities [1995] in using geodetic data to estimate the seismic risk in southern California has assumed that strain accumulated off the San Andreas fault is released by earthquakes located off the San Andreas fault. Thus they count the San Andreas contribution to total seismic moment accumulation more than once, leading to an overestimate of the seismicity for magnitude 6 and greater earthquakes in their Type C zones.

  9. Low strength of deep San Andreas fault gouge from SAFOD core (United States)

    Lockner, David A.; Morrow, Carolyn A.; Moore, Diane E.; Hickman, Stephen H.


    The San Andreas fault accommodates 28–34 mm yr−1 of right lateral motion of the Pacific crustal plate northwestward past the North American plate. In California, the fault is composed of two distinct locked segments that have produced great earthquakes in historical times, separated by a 150-km-long creeping zone. The San Andreas Fault Observatory at Depth (SAFOD) is a scientific borehole located northwest of Parkfield, California, near the southern end of the creeping zone. Core was recovered from across the actively deforming San Andreas fault at a vertical depth of 2.7 km (ref. 1). Here we report laboratory strength measurements of these fault core materials at in situ conditions, demonstrating that at this locality and this depth the San Andreas fault is profoundly weak (coefficient of friction, 0.15) owing to the presence of the smectite clay mineral saponite, which is one of the weakest phyllosilicates known. This Mg-rich clay is the low-temperature product of metasomatic reactions between the quartzofeldspathic wall rocks and serpentinite blocks in the fault2, 3. These findings provide strong evidence that deformation of the mechanically unusual creeping portions of the San Andreas fault system is controlled by the presence of weak minerals rather than by high fluid pressure or other proposed mechanisms1. The combination of these measurements of fault core strength with borehole observations1, 4, 5 yields a self-consistent picture of the stress state of the San Andreas fault at the SAFOD site, in which the fault is intrinsically weak in an otherwise strong crust.

  10. Fault rocks from the SAFOD core samples : implications for weakening at shallow depths along the San Andreas Fault, California

    NARCIS (Netherlands)

    Holdsworth, R.E.; van Diggelen, E.W.E.; Spiers, C.J.; Bresser, J.H.P. de; Walker, R.J.; Bown, L.


    The drilling of a deep borehole across the actively creeping Parkfield segment of the San Andreas Fault Zone (SAFZ), California, and collection of core materials permit direct geological study of fault zone processes at 2–3 km depth. The three drill cores sample both host and fault rocks and pass

  11. Neogene contraction between the San Andreas fault and the Santa Clara Valley, San Francisco Bay region, California (United States)

    McLaughlin, R.J.; Langenheim, V.E.; Schmidt, K.M.; Jachens, R.C.; Stanley, R.G.; Jayko, A.S.; McDougall, K.A.; Tinsley, J.C.; Valin, Z.C.


    In the southern San Francisco Bay region of California, oblique dextral reverse faults that verge northeastward from the San Andreas fault experienced triggered slip during the 1989 M7.1 Loma Prieta earthquake. The role of these range-front thrusts in the evolution of the San Andreas fault system and the future seismic hazard that they may pose to the urban Santa Clara Valley are poorly understood. Based on recent geologic mapping and geophysical investigations, we propose that the range-front thrust system evolved in conjunction with development of the San Andreas fault system. In the early Miocene, the region was dominated by a system of northwestwardly propagating, basin-bounding, transtensional faults. Beginning as early as middle Miocene time, however, the transtensional faulting was superseded by transpressional NE-stepping thrust and reverse faults of the range-front thrust system. Age constraints on the thrust faults indicate that the locus of contraction has focused on the Monte Vista, Shannon, and Berrocal faults since about 4.8 Ma. Fault slip and fold reconstructions suggest that crustal shortening between the San Andreas fault and the Santa Clara Valley within this time frame is ~21%, amounting to as much as 3.2 km at a rate of 0.6 mm/yr. Rates probably have not remained constant; average rates appear to have been much lower in the past few 100 ka. The distribution of coseismic surface contraction during the Loma Prieta earthquake, active seismicity, late Pleistocene to Holocene fluvial terrace warping, and geodetic data further suggest that the active range-front thrust system includes blind thrusts. Critical unresolved issues include information on the near-surface locations of buried thrusts, the timing of recent thrust earthquake events, and their recurrence in relation to earthquakes on the San Andreas fault.

  12. Migrating tremors illuminate complex deformation beneath the seismogenic San Andreas fault (United States)

    Shelly, David R.


    The San Andreas fault is one of the most extensively studied faults in the world, yet its physical character and deformation mode beneath the relatively shallow earthquake-generating portion remain largely unconstrained. Tectonic ‘non-volcanic’ tremor, a recently discovered seismic signal probably generated by shear slip on the deep extension of some major faults, can provide new insight into the deep fate of such faults, including that of the San Andreas fault near Parkfield, California. Here I examine continuous seismic data from mid-2001 to 2008, identifying tremor and decomposing the signal into different families of activity based on the shape and timing of the waveforms at multiple stations. This approach allows differentiation between activities from nearby patches of the deep fault and begins to unveil rich and complex patterns of tremor occurrence. I find that tremor exhibits nearly continuous migration, with the most extensive episodes propagating more than 20 kilometres along fault strike at rates of 15–80 kilometres per hour. This suggests that the San Andreas fault remains a localized through-going structure, at least to the base of the crust, in this area. Tremor rates and recurrence behaviour changed markedly in the wake of the 2004 magnitude-6.0 Parkfield earthquake, but these changes were far from uniform within the tremor zone, probably reflecting heterogeneous fault properties and static and dynamic stresses decaying away from the rupture. The systematic recurrence of tremor demonstrated here suggests the potential to monitor detailed time-varying deformation on this portion of the deep San Andreas fault, deformation which unsteadily loads the shallower zone that last ruptured in the 1857 magnitude-7.9 Fort Tejon earthquake.

  13. Scientific drilling into the San Andreas Fault Zone - an overview of SAFOD's first five years (United States)

    Zoback, Mark; Hickman, Stephen; Ellsworth, William; ,


    The San Andreas Fault Observatory at Depth (SAFOD) was drilled to study the physical and chemical processes controlling faulting and earthquake generation along an active, plate-bounding fault at depth. SAFOD is located near Parkfield, California and penetrates a section of the fault that is moving due to a combination of repeating microearthquakes and fault creep. Geophysical logs define the San Andreas Fault Zone to be relatively broad (~200 m), containing several discrete zones only 2–3 m wide that exhibit very low P- and S-wave velocities and low resistivity. Two of these zones have progressively deformed the cemented casing at measured depths of 3192 m and 3302 m. Cores from both deforming zones contain a pervasively sheared, cohesionless, foliated fault gouge that coincides with casing deformation and explains the observed extremely low seismic velocities and resistivity. These cores are being now extensively tested in laboratories around the world, and their composition, deformation mechanisms, physical properties, and rheological behavior are studied. Downhole measurements show that within 200 m (maximum) of the active fault trace, the direction of maximum horizontal stress remains at a high angle to the San Andreas Fault, consistent with other measurements. The results from the SAFOD Main Hole, together with the stress state determined in the Pilot Hole, are consistent with a strong crust/weak fault model of the San Andreas. Seismic instrumentation has been deployed to study physics of faulting—earthquake nucleation, propagation, and arrest—in order to test how laboratory-derived concepts scale up to earthquakes occurring in nature.

  14. The San Andreas Fault and a Strike-slip Fault on Europa (United States)


    The mosaic on the right of the south polar region of Jupiter's moon Europa shows the northern 290 kilometers (180 miles) of a strike-slip fault named Astypalaea Linea. The entire fault is about 810 kilometers (500 miles) long, the size of the California portion of the San Andreas fault on Earth which runs from the California-Mexico border north to the San Francisco Bay. The left mosaic shows the portion of the San Andreas fault near California's san Francisco Bay that has been scaled to the same size and resolution as the Europa image. Each covers an area approximately 170 by 193 kilometers(105 by 120 miles). The red line marks the once active central crack of the Europan fault (right) and the line of the San Andreas fault (left). A strike-slip fault is one in which two crustal blocks move horizontally past one another, similar to two opposing lanes of traffic. The overall motion along the Europan fault seems to have followed a continuous narrow crack along the entire length of the feature, with a path resembling stepson a staircase crossing zones which have been pulled apart. The images show that about 50 kilometers (30 miles) of displacement have taken place along the fault. Opposite sides of the fault can be reconstructed like a puzzle, matching the shape of the sides as well as older individual cracks and ridges that had been broken by its movements. Bends in the Europan fault have allowed the surface to be pulled apart. This pulling-apart along the fault's bends created openings through which warmer, softer ice from below Europa's brittle ice shell surface, or frozen water from a possible subsurface ocean, could reach the surface. This upwelling of material formed large areas of new ice within the boundaries of the original fault. A similar pulling apart phenomenon can be observed in the geological trough surrounding California's Salton Sea, and in Death Valley and the Dead Sea. In those cases, the pulled apart regions can include upwelled materials, but may

  15. Simulations of tremor-related creep reveal a weak crustal root of the San Andreas Fault (United States)

    Shelly, David R.; Bradley, Andrew M.; Johnson, Kaj M.


    Deep aseismic roots of faults play a critical role in transferring tectonic loads to shallower, brittle crustal faults that rupture in large earthquakes. Yet, until the recent discovery of deep tremor and creep, direct inference of the physical properties of lower-crustal fault roots has remained elusive. Observations of tremor near Parkfield, CA provide the first evidence for present-day localized slip on the deep extension of the San Andreas Fault and triggered transient creep events. We develop numerical simulations of fault slip to show that the spatiotemporal evolution of triggered tremor near Parkfield is consistent with triggered fault creep governed by laboratory-derived friction laws between depths of 20–35 km on the fault. Simulated creep and observed tremor northwest of Parkfield nearly ceased for 20–30 days in response to small coseismic stress changes of order 104 Pa from the 2003 M6.5 San Simeon Earthquake. Simulated afterslip and observed tremor following the 2004 M6.0 Parkfield earthquake show a coseismically induced pulse of rapid creep and tremor lasting for 1 day followed by a longer 30 day period of sustained accelerated rates due to propagation of shallow afterslip into the lower crust. These creep responses require very low effective normal stress of ~1 MPa on the deep San Andreas Fault and near-neutral-stability frictional properties expected for gabbroic lower-crustal rock.

  16. Habitat information in the region on the underwater San Andreas Fault - Topic: Exploring the Undersea San Andreas Fault: Revealing the Past, Present, and Future at the Centennial of the Great 1906 Earthquake (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — During this exploration, the first comprehensive high-resolution multi-beam sonar and seismic reflection survey of the Northern San Andreas Fault (NSAF) was...

  17. Paleoseismic Study on the Peninsula Section of the San Andreas Fault South of Crystal Springs Reservoir, San Mateo County, California (United States)

    Zachariasen, J. A.; Prentice, C. S.; Kozaci, O.; Sickler, R. R.; Baldwin, J. N.; Sanquini, A.; Knudsen, K. L.


    The Peninsula section of the San Andreas Fault is a significant hazard for the San Francisco Bay area, but little is known about the timing of earthquakes on this section of the fault prior to the great earthquake of April 18, 1906. An earthquake in 1838 resulted in strong shaking on the San Francisco Peninsula. Estimates of the magnitude of the 1838 earthquake vary from 6.8 to 7.4, based on historical accounts, and most workers have assumed that this event occurred on the San Andreas Fault. However, paleoseismic excavations across the fault near San Andreas Lake failed to provide evidence that the 1838 earthquake was associated with surface rupture on the Peninsula section of the San Andreas Fault (Prentice et al., 2008, 2009). Earlier work at the Filoli Estate, south of Crystal Springs Reservoirs, by Hall et al. (1999) suggested that both the 1838 and 1906 earthquakes ruptured the Peninsula section, based on the projected offsets of buried stream channels that crossed the fault. While this interpretation is permissible, the data also allow alternative interpretations that do not require surface rupture in 1838. We used LiDAR images produced from data collected by the GeoEarthScope project to search for promising paleoseismic sites along the Peninsula section of the San Andreas Fault. At a site about 1.2 km southeast of Crystal Springs Reservoir, we excavated two trenches across the fault and exposed fluvial gravel and overbank deposits cut by two distinct generations of faults. The younger set of faults break nearly to the ground surface, and we interpret these to represent 1906 surface faulting that has been buried post-1906 sediments. The older faults terminate below a colluvial wedge derived from one of the fluvial gravel deposits. The scarp-derived colluvium overlies a faulted fine-grained overbank deposit that in turn rests on the channel gravel, and represents the ground surface at the time of the older earthquake. The scarp-derived colluvium is overlain by

  18. Deformation rates across the San Andreas Fault system, central California determined by geology and geodesy (United States)

    Titus, Sarah J.

    The San Andreas fault system is a transpressional plate boundary characterized by sub-parallel dextral strike-slip faults separating internally deformed crustal blocks in central California. Both geodetic and geologic tools were used to understand the short- and long-term partitioning of deformation in both the crust and the lithospheric mantle across the plate boundary system. GPS data indicate that the short-term discrete deformation rate is ˜28 mm/yr for the central creeping segment of the San Andreas fault and increases to 33 mm/yr at +/-35 km from the fault. This gradient in deformation rates is interpreted to reflect elastic locking of the creeping segment at depth, distributed off-fault deformation, or some combination of these two mechanisms. These short-term fault-parallel deformation rates are slower than the expected geologic slip rate and the relative plate motion rate. Structural analysis of folds and transpressional kinematic modeling were used to quantify long-term distributed deformation adjacent to the Rinconada fault. Folding accommodates approximately 5 km of wrench deformation, which translates to a deformation rate of ˜1 mm/yr since the start of the Pliocene. Integration with discrete offset on the Rinconada fault indicates that this portion of the San Andreas fault system is approximately 80% strike-slip partitioned. This kinematic fold model can be applied to the entire San Andreas fault system and may explain some of the across-fault gradient in deformation rates recorded by the geodetic data. Petrologic examination of mantle xenoliths from the Coyote Lake basalt near the Calaveras fault was used to link crustal plate boundary deformation at the surface with models for the accommodation of deformation in the lithospheric mantle. Seismic anisotropy calculations based on xenolith petrofabrics suggest that an anisotropic mantle layer thickness of 35-85 km is required to explain the observed shear wave splitting delay times in central

  19. Aseismic Slip Events along the Southern San Andreas Fault System Captured by Radar Interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Vincent, P


    A seismic slip is observed along several faults in the Salton Sea and southernmost Landers rupture zone regions using interferometric synthetic aperture radar (InSAR) data spanning different time periods between 1992 and 1997. In the southernmost Landers rupture zone, projecting south from the Pinto Mountain Fault, sharp discontinuities in the interferometric phase are observed along the sub-parallel Burnt Mountain and Eureka Peak Faults beginning three months after the Landers earthquake and is interpreted to be post-Landers after-slip. Abrupt phase offsets are also seen along the two southernmost contiguous 11 km Durmid Hill and North Shore segments of the San Andreas Fault with an abrupt termination of slip near the northern end of the North Shore Segment. A sharp phase offset is seen across 20 km of the 30 km-long Superstition Hills Fault before phase decorrelation in the Imperial Valley along the southern 10 km of the fault prevents coherent imaging by InSAR. A time series of deformation interferograms suggest most of this slip occurred between 1993 and 1995 and none of it occurred between 1992 and 1993. A phase offset is also seen along a 5 km central segment of the Coyote Creek fault that forms a wedge with an adjoining northeast-southwest trending conjugate fault. Most of the slip observed on the southern San Andreas and Superstition Hills Faults occurred between 1993 and 1995--no slip is observed in the 92-93 interferograms. These slip events, especially the Burnt Mountain and Eureka Peak events, are inferred to be related to stress redistribution from the June, 1992 M{sub w} = 7.3 Landers earthquake. Best-fit elastic models of the San Andreas and Superstition Hills slip events suggest source mechanisms with seismic moments over three orders of magnitude larger than a maximum possible summation of seismic moments from all seismicity along each fault segment during the entire 4.8-year time interval spanned by the InSAR data. Aseismic moment releases of this

  20. Geophysical evidence for wedging in the San Gorgonio Pass structural knot, southern San Andreas fault zone, southern California (United States)

    Langenheim, V.E.; Jachens, R.C.; Matti, J.C.; Hauksson, E.; Morton, D.M.; Christensen, A.


    Geophysical data and surface geology define intertonguing thrust wedges that form the upper crust in the San Gorgonio Pass region. This picture serves as the basis for inferring past fault movements within the San Andreas system, which are fundamental to understanding the tectonic evolution of the San Gorgonio Pass region. Interpretation of gravity data indicates that sedimentary rocks have been thrust at least 5 km in the central part of San Gorgonio Pass beneath basement rocks of the southeast San Bernardino Mountains. Subtle, long-wavelength magnetic anomalies indicate that a magnetic body extends in the subsurface north of San Gorgonio Pass and south under Peninsular Ranges basement, and has a southern edge that is roughly parallel to, but 5-6 km south of, the surface trace of the Banning fault. This deep magnetic body is composed either of upper-plate rocks of San Gabriel Mountains basement or rocks of San Bernardino Mountains basement or both. We suggest that transpression across the San Gorgonio Pass region drove a wedge of Peninsular Ranges basement and its overlying sedimentary cover northward into the San Bernardino Mountains during the Neogene, offsetting the Banning fault at shallow depth. Average rates of convergence implied by this offset are broadly consistent with estimates of convergence from other geologic and geodetic data. Seismicity suggests a deeper detachment surface beneath the deep magnetic body. This interpretation suggests that the fault mapped at the surface evolved not only in map but also in cross-sectional view. Given the multilayered nature of deformation, it is unlikely that the San Andreas fault will rupture cleanly through the complex structures in San Gorgonio Pass. ?? 2005 Geological Society of America.

  1. Precise tremor source locations and amplitude variations along the lower-crustal central San Andreas Fault (United States)

    Shelly, David R.; Hardebeck, Jeanne L.


    We precisely locate 88 tremor families along the central San Andreas Fault using a 3D velocity model and numerous P and S wave arrival times estimated from seismogram stacks of up to 400 events per tremor family. Maximum tremor amplitudes vary along the fault by at least a factor of 7, with by far the strongest sources along a 25 km section of the fault southeast of Parkfield. We also identify many weaker tremor families, which have largely escaped prior detection. Together, these sources extend 150 km along the fault, beneath creeping, transitional, and locked sections of the upper crustal fault. Depths are mostly between 18 and 28 km, in the lower crust. Epicenters are concentrated within 3 km of the surface trace, implying a nearly vertical fault. A prominent gap in detectible activity is located directly beneath the region of maximum slip in the 2004 magnitude 6.0 Parkfield earthquake.

  2. Hydrogeologic Architecture of the San Andreas Fault near the Logan Quarry (United States)

    Xue, L.; Brodsky, E. E.; Erskine, J.; Fulton, P. M.; Carter, R.


    Hydrogeologic properties of fault zones are critical to the faulting processes; however, they are not well understood and difficult to measure in situ. Recording the tidal response of water level is a useful method to measure the in-situ properties. We utilize an array of wells near the San Andreas Fault zone in the Logan Quarry to study the fault zone hydrogeologic architecture by measuring the water tidal response. The measured specific storage and permeability show that there is a localized zone near the fault with higher specific storage and larger permeability than the surrounding region. This change of properties might be related to the fault zone fracture distribution. Surprisingly, the change of the specific storage is the clearest signal. The inferred compliance contrast is consistent with prior estimates of elastic moduli change in the near-fault environment, but the hydrogeologic effects of the compliance change have never before been measured on a major active fault. The observed specific storage structure implies that the fault zone plays an important role in permeability enhancement by seismic shaking. In addition, the measured diffusivity is about 10-2 m2/s, which is comparable to the post-earthquake hydraulic diffusivity measured on the Wenchuan Earthquake Fault. This observed high diffusivity with little variability inside the fault zone might suggest the accumulated pore pressure during interseismic period distributes over a broad region.

  3. Recurrence of seismic migrations along the central California segment of the San Andreas fault system (United States)

    Wood, M.D.; Allen, S.S.


    VERIFICATIONS of tectonic concepts1 concerning seafloor spreading are emerging in a manner that has direct bearing on earthquake prediction. Although the gross pattern of worldwide seismicity contributed to the formulation of the plate tectonic hypothesis, it is the space-time characteristics of this seismicity that may contribute more toward understanding the kinematics and dynamics of the driving mechanism long speculated to originate in the mantle. If the lithosphere is composed of plates that move essentially as rigid bodies, then there should be seismic edge effects associated with this movement. It is these interplate effects, especially seismic migration patterns, that we discuss here. The unidirectional propagation at constant velocity (80 km yr-1 east to west) for earthquakes (M???7.2) on the Antblian fault for the period 1939 to 1956 (ref. 2) is one of the earliest observations of such a phenomenon. Similar studies3,4 of the Alaska Aleutian seismic zone and certain regions of the west coast of South America suggest unidirectional and recurring migrations of earthquakes (M???7.7) occur in these areas. Between these two regions along the great transform faults of the west coast of North America, there is some evidence 5 for unidirectional, constant velocity and recurrent migration of great earthquakes. The small population of earthquakes (M>7.2) in Savage's investigation5 indicates a large spatial gap along the San Andreas system in central California from 1830 to 1970. Previous work on the seismicity of this gap in central California indicates that the recurrence curves remain relatively constant, independent of large earthquakes, for periods up to a century6. Recurrence intervals for earthquakes along the San Andreas Fault have been calculated empirically by Wallace7 on the basis of geological evidence, surface measurements and assumptions restricted to the surficial seismic layer. Here we examine the evidence for recurrence of seismic migrations along

  4. High resolution measurements of aseismic slip (creep) on the San Andreas fault system from Parkfield to San Francisco Bay area; 1966 to the present (United States)

    U.S. Geological Survey, Department of the Interior — These data provide measures of aseismic slip (creep) at approximately 40 sites located on the San Andreas, Hayward, and Calaveras faults in Central California from...

  5. A critical evaluation of crustal dehydration as the cause of an overpressured and weak San Andreas Fault (United States)

    Fulton, P.M.; Saffer, D.M.; Bekins, B.A.


    Many plate boundary faults, including the San Andreas Fault, appear to slip at unexpectedly low shear stress. One long-standing explanation for a "weak" San Andreas Fault is that fluid release by dehydration reactions during regional metamorphism generates elevated fluid pressures that are localized within the fault, reducing the effective normal stress. We evaluate this hypothesis by calculating realistic fluid production rates for the San Andreas Fault system, and incorporating them into 2-D fluid flow models. Our results show that for a wide range of permeability distributions, fluid sources from crustal dehydration are too small and short-lived to generate, sustain, or localize fluid pressures in the fault sufficient to explain its apparent mechanical weakness. This suggests that alternative mechanisms, possibly acting locally within the fault zone, such as shear compaction or thermal pressurization, may be necessary to explain a weak San Andreas Fault. More generally, our results demonstrate the difficulty of localizing large fluid pressures generated by regional processes within near-vertical fault zones. ?? 2009 Elsevier B.V.

  6. Low resistivity and permeability in actively deforming shear zones on the San Andreas Fault at SAFOD (United States)

    Morrow, Carolyn A.; Lockner, David A.; Hickman, Stephen H.


    The San Andreas Fault Observatory at Depth (SAFOD) scientific drillhole near Parkfield, California crosses the San Andreas Fault at a depth of 2.7 km. Downhole measurements and analysis of core retrieved from Phase 3 drilling reveal two narrow, actively deforming zones of smectite-clay gouge within a roughly 200 m-wide fault damage zone of sandstones, siltstones and mudstones. Here we report electrical resistivity and permeability measurements on core samples from all of these structural units at effective confining pressures up to 120 MPa. Electrical resistivity (~10 ohm-m) and permeability (10-21 to 10-22 m2) in the actively deforming zones were one to two orders of magnitude lower than the surrounding damage zone material, consistent with broader-scale observations from the downhole resistivity and seismic velocity logs. The higher porosity of the clay gouge, 2 to 8 times greater than that in the damage zone rocks, along with surface conduction were the principal factors contributing to the observed low resistivities. The high percentage of fine-grained clay in the deforming zones also greatly reduced permeability to values low enough to create a barrier to fluid flow across the fault. Together, resistivity and permeability data can be used to assess the hydrogeologic characteristics of the fault, key to understanding fault structure and strength. The low resistivities and strength measurements of the SAFOD core are consistent with observations of low resistivity clays that are often found in the principal slip zones of other active faults making resistivity logs a valuable tool for identifying these zones.

  7. Tidal triggering of earthquakes suggests poroelastic behavior on the San Andreas Fault (United States)

    Delorey, Andrew; Van Der Elst, Nicholas; Johnson, Paul


    Tidal triggering of earthquakes is hypothesized to provide quantitative information regarding the fault's stress state, poroelastic properties, and may be significant for our understanding of seismic hazard. To date, studies of regional or global earthquake catalogs have had only modest successes in identifying tidal triggering. We posit that the smallest events that may provide additional evidence of triggering go unidentified and thus we developed a technique to improve the identification of very small magnitude events. We identify events applying a method known as inter-station seismic coherence where we prioritize detection and discrimination over characterization. Here we show tidal triggering of earthquakes on the San Andreas Fault. We find the complex interaction of semi-diurnal and fortnightly tidal periods exposes both stress threshold and critical state behavior. Our findings reveal earthquake nucleation processes and pore pressure conditions – properties of faults that are difficult to measure, yet extremely important for characterizing earthquake physics and seismic hazards.

  8. Cradle of the Earthquake: Exploring the Underwater San Andreas Fault on the R/V Pacific Storm and the SRV Derek M. Baylis between 20100910 and 20101003 (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Over one hundred years after the devastating Great 1906 Earthquake that nearly destroyed San Francisco, this expedition explored the Northern San Andreas Fault, the...

  9. Ultracataclasite structure and friction processes of the Punchbowl fault, San Andreas system, California (United States)

    Chester, Frederick M.; Chester, Judith S.


    The Punchbowl fault is an exhumed, 40+ km displacement fault of the San Andreas system. In the Devil's Punchbowl, the fault contains a continuous ultracataclasite layer along which the Punchbowl Formation sandstone and an igneous and metamorphic basement complex are juxtaposed. The fabric of the ultracataclasite layer and surrounding rock indicate that nearly all of the fault displacement occurred in the layer. By analogy with nearby active faults, we assume that the Punchbowl fault was seismogenic and that the ultracataclasite structure records the passage of numerous earthquake ruptures. We have mapped the ultracataclasite layer at 1 : 1 and 1 : 10 to determine the mode of failure and to constrain the processes of seismic slip. On the basis of color, cohesion, fracture and vein fabric, and porphyroclast lithology, two main types of ultracataclasite are distinguished in the layer: an olive-black ultracataclasite in contact with the basement, and a dark yellowish brown ultracataclasite in contact with the sandstone. The two are juxtaposed along a continuous contact that is often coincident with a single, continuous, nearly planar, prominent fracture surface (pfs) that extends the length of the ultracataclasite layer in all exposures. No significant mixing of the brown and black ultracataclasites occurred by offset on anastomosing shear surfaces that cut the contact or by mobilization and injection of one ultracataclasite into the other. The ultracataclasites are cohesive throughout except for thin accumulations of less cohesive, reworked ultracataclasite along the pfs. Structural relations suggest that: (1) the black and brown ultracataclasite were derived from the basement and sandstone, respectively; (2) the black and brown ultracataclasites were juxtaposed along the pfs; (3) the subsequent, final several kilometers of slip on the Punchbowl fault occurred along the pfs; and (4) earthquake ruptures followed the pfs without significant branching or jumping to other

  10. Discovery Along the San Andreas Fault: Relocating Photographs From the 1906 Earthquake in San Francisco and San Mateo Counties (United States)

    Grove, K.; Prentice, C.; Polly, J.; Yuen, C.; Wu, K.; Zhong, S.; Lopez, J.


    April of 2006 will mark the 100-year anniversary of the great 1906 San Francisco earthquake. This earthquake was important not only because of its human tragedy (thousands of dead or homeless people), but also because of its scientific significance. The 8.3 magnitude earthquake ruptured 430 km of the northern San Andreas fault (SAF) and lasted nearly one minute. Investigations after the earthquake led to discoveries that were the beginning of modern earthquake theories and measuring instruments. This was also one of the first large-scale natural disasters to be photographed. Our research group, which is part of the National Science Foundation funded SF-ROCKS program, acquired photographs that were taken shortly after the earthquake in downtown San Francisco and along the SAF in San Mateo County. The SAF photos are part of a Geographical Information System (GIS) database being published on a U.S. Geological Survey web site. The goal of our project was to improve estimates of photograph locations and to compare the landscape features that were visible after the earthquake with the landscape that we see today. We used the GIS database to find initial photo locations, and we then used a high-precision Global Positioning System (GPS) to measure the geographic coordinates of the locations once we matched our view to what we saw in a photo. Where possible, we used a digital camera to retake photos from the same position, to show the difference in the landscape 100 years later. The 1906 photos show fault zone features such as ground rupture, sag ponds, shutter ridges, and offset fences. Changes to the landscape since 1906 have included erosion and grading of the land, building of houses and other structures, and more tree cover compared to previous grassland vegetation. Our project is part of 1906 Earthquake Centennial activities; it is contributing to the photo archive that helps scientists and engineers who study earthquakes and their effects. It will also help the

  11. Deep rock damage in the San Andreas Fault revealed by P- and S-type fault-zone-guided waves (United States)

    Ellsworth, William L.; Malin, Peter E.


    Damage to fault-zone rocks during fault slip results in the formation of a channel of low seismic-wave velocities. Within such channels guided seismic waves, denoted by Fg, can propagate. Here we show with core samples, well logs and Fg-waves that such a channel is crossed by the SAFOD (San Andreas Fault Observatory at Depth) borehole at a depth of 2.7 km near Parkfield, California, USA. This laterally extensive channel extends downwards to at least half way through the seismogenic crust, more than about 7 km. The channel supports not only the previously recognized Love-type- (FL) and Rayleigh-type- (FR) guided waves, but also a new fault-guided wave, which we name FF. As recorded 2.7 km underground, FF is normally dispersed, ends in an Airy phase, and arrives between the P- and S-waves. Modelling shows that FF travels as a leaky mode within the core of the fault zone. Combined with the drill core samples, well logs and the two other types of guided waves, FF at SAFOD reveals a zone of profound, deep, rock damage. Originating from damage accumulated over the recent history of fault movement, we suggest it is maintained either by fracturing near the slip surface of earthquakes, such as the 1857 Fort Tejon M 7.9, or is an unexplained part of the fault-creep process known to be active at this site.

  12. Low-altitude aerial color digital photographic survey of the San Andreas Fault (United States)

    Lynch, David K.; Hudnut, Kenneth W.; Dearborn, David S.P.


    Ever since 1858, when Gaspard-Félix Tournachon (pen name Félix Nadar) took the first aerial photograph (Professional Aerial Photographers Association 2009), the scientific value and popular appeal of such pictures have been widely recognized. Indeed, Nadar patented the idea of using aerial photographs in mapmaking and surveying. Since then, aerial imagery has flourished, eventually making the leap to space and to wavelengths outside the visible range. Yet until recently, the availability of such surveys has been limited to technical organizations with significant resources. Geolocation required extensive time and equipment, and distribution was costly and slow. While these situations still plague older surveys, modern digital photography and lidar systems acquire well-calibrated and easily shared imagery, although expensive, platform-specific software is sometimes still needed to manage and analyze the data. With current consumer-level electronics (cameras and computers) and broadband internet access, acquisition and distribution of large imaging data sets are now possible for virtually anyone. In this paper we demonstrate a simple, low-cost means of obtaining useful aerial imagery by reporting two new, high-resolution, low-cost, color digital photographic surveys of selected portions of the San Andreas fault in California. All pictures are in standard jpeg format. The first set of imagery covers a 92-km-long section of the fault in Kern and San Luis Obispo counties and includes the entire Carrizo Plain. The second covers the region from Lake of the Woods to Cajon Pass in Kern, Los Angeles, and San Bernardino counties (151 km) and includes Lone Pine Canyon soon after the ground was largely denuded by the Sheep Fire of October 2009. The first survey produced a total of 1,454 oblique digital photographs (4,288 x 2,848 pixels, average 6 Mb each) and the second produced 3,762 nadir images from an elevation of approximately 150 m above ground level (AGL) on the

  13. Frictional strength heterogeneity and surface heat flow: Implications for the strength of the creeping San Andreas fault (United States)

    d'Alessio, M. A.; Williams, C.F.; Burgmann, R.


    Heat flow measurements along much of the San Andreas fault (SAF) constrain the apparent coefficient of friction (??app) of the fault to 0.2 should be detectable even with the sparse existing observations, implying that ??app for the creeping section is as low as the surrounding SAF. Because the creeping section does not slip in large earthquakes, the mechanism controlling its weakness is not related to dynamic processes resulting from high slip rate earthquake ruptures. Copyright 2006 by the American Geophysical Union.

  14. Inferring fault rheology from low-frequency earthquakes on the San Andreas (United States)

    Beeler, Nicholas M.; Thomas, Amanda; Bürgmann, Roland; Shelly, David R.


    Families of recurring low-frequency earthquakes (LFEs) within nonvolcanic tremor (NVT) on the San Andreas fault in central California show strong sensitivity to shear stress induced by the daily tidal cycle. LFEs occur at all levels of the tidal shear stress and are in phase with the very small, ~400 Pa, stress amplitude. To quantitatively explain the correlation, we use a model from the existing literature that assumes the LFE sources are small, persistent regions that repeatedly fail during shear of a much larger scale, otherwise aseismically creeping fault zone. The LFE source patches see tectonic loading, creep of the surrounding fault which may be modulated by the tidal stress, and direct tidal loading. If the patches are small relative to the surrounding creeping fault then the stressing is dominated by fault creep, and if patch failure occurs at a threshold stress, then the resulting seismicity rate is proportional to the fault creep rate or fault zone strain rate. Using the seismicity rate as a proxy for strain rate and the tidal shear stress, we fit the data with possible fault rheologies that produce creep in laboratory experiments at temperatures of 400 to 600°C appropriate for the LFE source depth. The rheological properties of rock-forming minerals for dislocation creep and dislocation glide are not consistent with the observed fault creep because strong correlation between small stress perturbations and strain rate requires perturbation on the order of the ambient stress. The observed tidal modulation restricts ambient stress to be at most a few kilopascal, much lower than rock strength. A purely rate dependent friction is consistent with the observations only if the product of the friction rate dependence and effective normal stress is ~ 0.5 kPa. Extrapolating the friction rate strengthening dependence of phyllosilicates (talc) to depth would require the effective normal stress to be ~50 kPa, implying pore pressure is lithostatic. If the LFE

  15. Does paleoseismology forecast the historic rates of large earthquakes on the San Andreas fault system? (United States)

    Biasi, Glenn; Scharer, Katherine M.; Weldon, Ray; Dawson, Timothy E.


    The 98-year open interval since the most recent ground-rupturing earthquake in the greater San Andreas boundary fault system would not be predicted by the quasi-periodic recurrence statistics from paleoseismic data. We examine whether the current hiatus could be explained by uncertainties in earthquake dating. Using seven independent paleoseismic records, 100 year intervals may have occurred circa 1150, 1400, and 1700 AD, but they occur in a third or less of sample records drawn at random. A second method sampling from dates conditioned on the existence of a gap of varying length suggests century-long gaps occur 3-10% of the time. A combined record with more sites would lead to lower probabilities. Systematic data over-interpretation is considered an unlikely explanation. Instead some form of non-stationary behaviour seems required, perhaps through long-range fault interaction. Earthquake occurrence since 1000 AD is not inconsistent with long-term cyclicity suggested from long runs of earthquake simulators.

  16. Holocene slip rates along the San Andreas Fault System in the San Gorgonio Pass and implications for large earthquakes in southern California (United States)

    Heermance, Richard V.; Yule, Doug


    The San Gorgonio Pass (SGP) in southern California contains a 40 km long region of structural complexity where the San Andreas Fault (SAF) bifurcates into a series of oblique-slip faults with unknown slip history. We combine new 10Be exposure ages (Qt4: 8600 (+2100, -2200) and Qt3: 5700 (+1400, -1900) years B.P.) and a radiocarbon age (1260 ± 60 years B.P.) from late Holocene terraces with scarp displacement of these surfaces to document a Holocene slip rate of 5.7 (+2.7, -1.5) mm/yr combined across two faults. Our preferred slip rate is 37-49% of the average slip rates along the SAF outside the SGP (i.e., Coachella Valley and San Bernardino sections) and implies that strain is transferred off the SAF in this area. Earthquakes here most likely occur in very large, throughgoing SAF events at a lower recurrence than elsewhere on the SAF, so that only approximately one third of SAF ruptures penetrate or originate in the pass.Plain Language SummaryHow large are earthquakes on the southern San Andreas Fault? The answer to this question depends on whether or not the earthquake is contained only along individual fault sections, such as the Coachella Valley section north of Palm Springs, or the rupture crosses multiple sections including the area through the San Gorgonio Pass. We have determined the age and offset of faulted stream deposits within the San Gorgonio Pass to document slip rates of these faults over the last 10,000 years. Our results indicate a long-term slip rate of 6 mm/yr, which is almost 1/2 of the rates east and west of this area. These new rates, combined with faulted geomorphic surfaces, imply that large magnitude earthquakes must occasionally rupture a 300 km length of the San Andreas Fault from the Salton Sea to the Mojave Desert. Although many ( 65%) earthquakes along the southern San Andreas Fault likely do not rupture through the pass, our new results suggest that large >Mw 7.5 earthquakes are possible on the southern San Andreas Fault and likely

  17. The Evergreen basin and the role of the Silver Creek fault in the San Andreas fault system, San Francisco Bay region, California (United States)

    Jachens, Robert C.; Wentworth, Carl M.; Graymer, Russell W.; Williams, Robert; Ponce, David A.; Mankinen, Edward A.; Stephenson, William J.; Langenheim, Victoria


    The Evergreen basin is a 40-km-long, 8-km-wide Cenozoic sedimentary basin that lies mostly concealed beneath the northeastern margin of the Santa Clara Valley near the south end of San Francisco Bay (California, USA). The basin is bounded on the northeast by the strike-slip Hayward fault and an approximately parallel subsurface fault that is structurally overlain by a set of west-verging reverse-oblique faults which form the present-day southeastward extension of the Hayward fault. It is bounded on the southwest by the Silver Creek fault, a largely dormant or abandoned fault that splays from the active southern Calaveras fault. We propose that the Evergreen basin formed as a strike-slip pull-apart basin in the right step from the Silver Creek fault to the Hayward fault during a time when the Silver Creek fault served as a segment of the main route by which slip was transferred from the central California San Andreas fault to the Hayward and other East Bay faults. The dimensions and shape of the Evergreen basin, together with palinspastic reconstructions of geologic and geophysical features surrounding it, suggest that during its lifetime, the Silver Creek fault transferred a significant portion of the ∼100 km of total offset accommodated by the Hayward fault, and of the 175 km of total San Andreas system offset thought to have been accommodated by the entire East Bay fault system. As shown previously, at ca. 1.5–2.5 Ma the Hayward-Calaveras connection changed from a right-step, releasing regime to a left-step, restraining regime, with the consequent effective abandonment of the Silver Creek fault. This reorganization was, perhaps, preceded by development of the previously proposed basin-bisecting Mount Misery fault, a fault that directly linked the southern end of the Hayward fault with the southern Calaveras fault during extinction of pull-apart activity. Historic seismicity indicates that slip below a depth of 5 km is mostly transferred from the Calaveras

  18. Depth-dependent mantle anisotropy below the San Andreas fault system: Apparent splitting parameters and waveforms (United States)

    Hartog, Renate; Schwartz, Susan Y.


    We measure apparent teleseismic shear wave splitting parameters at several stations of the Berkeley Digital Seismic Network (BDSN) and three temporary broadband stations of the University of California at Santa Cruz located near the San Andreas fault system in northern and central California. Previously proposed anisotropic models for the region include a two-layered structure and a structure with a constant degree of anisotropy and a horizontal fast axis that gradually rotates as a function of depth. We significantly increase the number of observations and confirm the existence of depth-dependent anisotropy beneath the San Andreas fault system. We also investigate the extent to which the enhanced data set can constrain the details of the depth-dependence. Using theoretical expressions, we determine a suite of two-layer models that fit our observations and result in practically indistinguishable apparent splitting parameters. The wide range of acceptable models indicates that apparent splitting parameters alone cannot constrain all four parameters that specify the two anisotropic layers (upper and lower fast polarization directions and delay times). Synthetic seismograms for three very different two-layer models chosen from our suite of acceptable models and a model with a gradually rotating fast axis show subtle waveform variations, and apparent splitting parameters measured from these records do not overlap. Hence we conclude that waveforms indeed contain additional information about the anisotropic structure. We incorporate waveform data by searching for the four splitting parameters of two-layer models that minimize the splitting of several records at each station simultaneously. The resulting models largely overlap with the models obtained using the theoretical expressions, which indicates that the addition of waveform data is not sufficient to uniquely determine all four parameters of a two-layer model. Constraining the upper fast polarization direction to be

  19. Subsurface geometry of the San Andreas-Calaveras fault junction: influence of serpentinite and the Coast Range Ophiolite (United States)

    Watt, Janet Tilden; Ponce, David A.; Graymer, Russell W.; Jachens, Robert C.; Simpson, Robert W.


    While an enormous amount of research has been focused on trying to understand the geologic history and neotectonics of the San Andreas-Calaveras fault (SAF-CF) junction, fundamental questions concerning fault geometry and mechanisms for slip transfer through the junction remain. We use potential-field, geologic, geodetic, and seismicity data to investigate the 3-D geologic framework of the SAF-CF junction and identify potential slip-transferring structures within the junction. Geophysical evidence suggests that the San Andreas and Calaveras fault zones dip away from each other within the northern portion of the junction, bounding a triangular-shaped wedge of crust in cross section. This wedge changes shape to the south as fault geometries change and fault activity shifts between fault strands, particularly along the Calaveras fault zone (CFZ). Potential-field modeling and relocated seismicity suggest that the Paicines and San Benito strands of the CFZ dip 65° to 70° NE and form the southwest boundary of a folded 1 to 3 km thick tabular body of Coast Range Ophiolite (CRO) within the Vallecitos syncline. We identify and characterize two steeply dipping, seismically active cross structures within the junction that are associated with serpentinite in the subsurface. The architecture of the SAF-CF junction presented in this study may help explain fault-normal motions currently observed in geodetic data and help constrain the seismic hazard. The abundance of serpentinite and related CRO in the subsurface is a significant discovery that not only helps constrain the geometry of structures but may also help explain fault behavior and the tectonic evolution of the SAF-CF junction.

  20. Correlation of clayey gouge in a surface exposure of the San Andreas fault with gouge at depth from SAFOD: Implications for the role of serpentinite in fault mechanics (United States)

    Moore, Diane E.; Rymer, Michael J.


    Magnesium-rich clayey gouge similar to that comprising the two actively creeping strands of the San Andreas Fault in drill core from the San Andreas Fault Observatory at Depth (SAFOD) has been identified in a nearby outcrop of serpentinite within the fault zone at Nelson Creek. Each occurrence of the gouge consists of porphyroclasts of serpentinite and sedimentary rocks dispersed in a fine-grained, foliated matrix of Mg-rich smectitic clays. The clay minerals in all three gouges are interpreted to be the product of fluid-assisted, shear-enhanced reactions between quartzofeldspathic wall rocks and serpentinite that was tectonically entrained in the fault from a source in the Coast Range Ophiolite. We infer that the gouge at Nelson Creek connects to one or both of the gouge zones in the SAFOD core, and that similar gouge may occur at depths in between. The special significance of the outcrop is that it preserves the early stages of mineral reactions that are greatly advanced at depth, and it confirms the involvement of serpentinite and the Mg-rich phyllosilicate minerals that replace it in promoting creep along the central San Andreas Fault.

  1. Stress-Induced Borehole Failure in the SAFOD Pilot Hole: Implications for the Strength of the San Andreas Fault at Parkfield (United States)

    Hickman, S.; Zoback, M.


    The San Andreas Fault Observatory at Depth (SAFOD) is a comprehensive project to drill, core and instrument an inclined borehole across the San Andreas Fault Zone to a depth of 4 km. A 2.2-km-deep vertical pilot hole was drilled in the summer of 2002 at the same surface location planned for SAFOD. This site is 1.8 km southwest of the San Andreas Fault near Parkfield, CA, on a segment of the fault that moves through a combination of aseismic creep and repeating microearthquakes. One of the primary goals of the pilot hole was to better define the thermomechanical setting of the San Andreas Fault Zone at Parkfield prior to drilling of the main SAFOD hole. Ultrasonic borehole televiewer logs acquired in the SAFOD pilot hole reveal extensive stress-induced borehole breakouts at depths from 0.8 to 2.2 km. Preliminary analysis of the orientations of these breakouts indicates that the direction of the maximum horizontal compressive stress, SHmax, is approximately 30° from the strike of the San Andreas Fault to a depth of ~1.6 km. However, a clockwise stress rotation is observed with increasing depth such that the SHmax direction approaches 70° to the strike of the fault at 2.0 to 2.2 km. This lowermost stress orientation is in fairly good agreement with SHmax directions seen at much greater distances (>10-20 km) from the San Andreas Fault in central California. Although the absolute magnitudes of the horizontal principal stresses will not be known until hydraulic fracturing tests are conducted in the pilot hole next year, observations of drilling-induced tensile fractures in a Formation Micro-Imager log confirm these stress orientations and indicate that the horizontal differential stress in the crust adjacent to the fault may be quite high. If so, then the upper ~1.6 km of the San Andreas Fault at Parkfield is supporting the levels of shear stress predicted by Byerlee's law for those depths. However, the rotation of SHmax toward fault-normal compression at greater depth

  2. Evaluation of hypotheses for right-lateral displacement of Neogene strata along the San Andreas Fault between Parkfield and Maricopa, California (United States)

    Stanley, Richard G.; Barron, John A.; Powell, Charles L.


    We used geological field studies and diatom biostratigraphy to test a published hypothesis that Neogene marine siliceous strata in the Maricopa and Parkfield areas, located on opposite sides of the San Andreas Fault, were formerly contiguous and then were displaced by about 80–130 kilometers (km) of right-lateral slip along the fault. In the Maricopa area on the northeast side of the San Andreas Fault, the upper Miocene Bitterwater Creek Shale consists of hard, siliceous shale with dolomitic concretions and turbidite sandstone interbeds. Diatom assemblages indicate that the Bitterwater Creek Shale was deposited about 8.0–6.7 million years before present (Ma) at the same time as the uppermost part of the Monterey Formation in parts of coastal California. In the Parkfield area on the southwest side of the San Andreas Fault, the upper Miocene Pancho Rico Formation consists of soft to indurated mudstone and siltstone and fossiliferous, bioturbated sandstone. Diatom assemblages from the Pancho Rico indicate deposition about 6.7–5.7 Ma (latest Miocene), younger than the Bitterwater Creek Shale and at about the same time as parts of the Sisquoc Formation and Purisima Formation in coastal California. Our results show that the Bitterwater Creek Shale and Pancho Rico Formation are lithologically unlike and of different ages and therefore do not constitute a cross-fault tie that can be used to estimate rightlateral displacement along the San Andreas Fault.In the Maricopa area northeast of the San Andreas Fault, the Bitterwater Creek Shale overlies conglomeratic fan-delta deposits of the upper Miocene Santa Margarita Formation, which in turn overlie siliceous shale of the Miocene Monterey Formation from which we obtained a diatom assemblage dated at about 10.0–9.3 Ma. Previous investigations noted that the Santa Margarita Formation in the Maricopa area contains granitic and metamorphic clasts derived from sources in the northern Gabilan Range, on the opposite side of

  3. Observations and modeling of shallow fault creep along the San Andreas Fault system (United States)

    Wei, Meng

    This dissertation focuses on observations and modeling of fault creep in California aiming to understand the relationship between creep and earthquakes and assess the earthquake hazards in California. Chapter 1 gives an introduction of fault creep research in California, geodetic methods used to measure fault creep, and mechanism of fault creep. Chapter 2 documents an investigate on a creep event on the Supersitition Hills Fault in Southern California and the spatial and temporal variations in slip history between 1992 and 2008 using ERS, and Envisat Satellite data confirming that the fault creep is confined within the sediments layer and is probably due to the low normal stress in unconsolidated sediments. Chapter 3 presents a study on triggered slip on faults in the Salton Trough by the 2010 El Mayor-Cucapah Mw 7.2 earthquake. Chapter 4 compiles geodetic data and investigates the relationship between shallow stress accumulating rate and creep rate. Chapter 5 and 6 explores two technical projects related to fault creep observations in California. Chapter 5 analyzes decorrelation of L-band and C-band interferograms in California with implications for future fault creep study. Chapter 6 proposes an optimal way to combine GPS and InSAR to measure interseismic deformation, including fault creep. The proposed method is compared with other method and the improvements are observed. Chapter 7 presents the conclusions of the previous six chapters. Chapter 8 presents my work in the first two years in graduate school, which is not related to fault creep. We compute global maps of surface minus basal heat flow that show qualitative agreement with heat flow based on the inverse square root of age relation. In the beginning of each chapter, I provide you an earthquake safety tip. I borrowed them from an interesting website for your safety and interests. Hopefully it could be one more motivation to read through my thesis. I didn't bother to invent them, as Ralph Waldo Emerson

  4. Variation in aseismic slip and fault normal strain along the creeping section of the San Andreas fault from GPS, InSAR and trilateration data (United States)

    Rolandone, F.; Johanson, I.; Bürgmann, R.; Agnew, D.


    In central California most of the relative motion between the Pacific and North American plates is accommodated by strike slip along the San Andreas fault system. However, a small amount of convergence is accommodated by compressional structures in the California Coast Ranges on both sides of the fault. Recent examples of such activity are the Coalinga and the 2003 San Simeon earthquakes. Along the central San Andreas fault (CSAF), from San Juan Bautista to Parkfield, almost all the slip along the CSAF in the brittle upper crust is accommodated aseismically. We use GPS, InSAR and trilateration data to resolve both the distribution of aseismic slip along the CSAF, and the deformation across adjacent, secondary fault structures. In 2003 and 2004, we conducted several GPS surveys along the CSAF. We resurveyed 15 stations of the San Benito triangulation and trilateration network, which extends 40 km to the northeast of the creeping segment. We combine these measurements with old EDM measurements and data from a GPS campaign in 1998. We also occupied 13 sites along the creeping segment, for which previous data exist in the SCEC archive. These dense GPS measurements, along with data from permanent GPS stations in the area, allow us to constrain the regional strain distribution and contributions from adjacent faults. With the addition of InSAR data, we can also better resolve active strain accumulation and aseismic slip along the CSAF. We use a stack of about 10 interferograms from ERS-1 and ERS-2 satellites spanning 8 years. InSAR is well suited to monitoring details of the shallow slip along the CSAF and, in concert with the broadly spaced GPS velocities, to resolving the distribution of deformation along and across the plate boundary. The results are the basis for determining the kinematics of spatially variable fault slip on the CSAF, and help to better constrain the fault's constitutive properties, and fault interaction processes.

  5. The Ash of Ohlson Ranch: A well-dated Stratigraphic Marker for Constraining Deformation Across the Northern San Andreas Fault (United States)

    McLaughlin, R. J.; Vazquez, J. A.; Fleck, R. J.; DeLong, S.; Sarna-Wojcicki, A.; Wan, E.; Powell, C., II; Prentice, C. S.


    The marine to non-marine transgressional - regressional Ohlson Ranch Formation of northern California was deposited mainly east of the San Andreas Fault and the Gualala structural block during Pliocene sea level high stands. The formation transitions eastward from marine to fluvial deposits and the marine strata are deposited on a mildly warped, pholad-bored erosional surface cut near Pliocene sea level (probably above storm wave-base), on rocks of the Coastal and Central belts of the Franciscan Complex. West of the San Andreas fault near Point Arena, a right-laterally displaced remnant of the wave-cut surface occurs at ca. 100m above modern sea level. East of the fault this surface varies in elevation from ca. 200-350m and a 12-15 cm thick light gray silicic tephra, the ash of Ohlson Ranch (AOR) locally occurs ~10m above the base of the marine section. The AOR consists of very fine-grained glass shards with conspicuous brown biotite in the upper 2 cm and rare co-magmatic clinopyroxene, hornblende and euhedral, weakly zoned zircons. The zircons are relatively uniform in size and little abraded, suggesting they are primary and not re-worked. The fine-grained nature of the AOR deposit suggests it is water lain and chemical analysis of the volcanic glass indicates that the eruptive source was in the southern Cascade Range. We analyzed both polished section mounts of zircon crystals and unpolished rims by ion microprobe (SHRIMP-RG) and LA-ICPMS in order to establish a precise U-Pb age for the AOR. Ages were adjusted for initial 230Th deficiency in the U-Pb chain using Th/U measured in zircon and host glass shards. Thirty-two zircon grains measured by LA-ICPMS at the University of Arizona LaserChron Center yield a mean U-Pb age of 4.58 ± 0.30 Ma (2σ , MSWD=0.53, n=23). SHRIMP analyses of zircon interiors exposed in polished epoxy-mounts yield a mean U-Pb age of 4.36 ± 0.11 Ma (2σ, MSWD 0.72, n=19). To further refine the likely eruption age of the AOR, the SHRIMP was

  6. (U-Th)/He thermochronometry reveals Pleistocene punctuated deformation and synkinematic hematite mineralization in the Mecca Hills, southernmost San Andreas Fault zone (United States)

    Moser, Amy C.; Evans, James P.; Ault, Alexis K.; Janecke, Susanne U.; Bradbury, Kelly K.


    The timing, tempo, and processes of punctuated deformation in strike-slip fault systems are challenging to resolve in the rock record. Faults in the Mecca Hills, adjacent to the southernmost San Andreas Fault, California, accommodate active deformation and exhumation in the Plio-Pleistocene sedimentary rocks and underlying crystalline basement. We document the spatiotemporal patterns of San Andreas Fault-related deformation as recorded in crystalline basement rocks of the Mecca Hills using fault microstructural observations, geochemical data, and hematite (n = 24) and apatite (n = 44) (U-Th)/He (hematite He, apatite He) thermochronometry data. Reproducible mean hematite He dates from minor hematite-coated fault surfaces in the Painted Canyon Fault damage zone range from ∼0.7-0.4 Ma and are younger than ∼1.2 Ma apatite He dates from adjacent crystalline basement host rock. These data reveal concomitant Pleistocene pulses of fault slip, fluid flow, and synkinematic hematite mineralization. Hematite textures, crystal morphology, and hematite He data patterns imply some damage zone deformation occurred via cyclic crack-seal and creep processes. Apatite He data from crystalline basement define distinct date-eU patterns and indicate cooling across discrete fault blocks in the Mecca Hills. Uniform ∼1.2 Ma apatite He dates regardless of eU are located exclusively between the Painted Canyon and Platform faults. Outside of this fault block, samples yield individual apatite He dates from ∼30-1 Ma that define a positive apatite He date-eU correlation. These patterns reveal focused exhumation away from the main trace of the San Andreas Fault at ∼1.2 Ma. Low-temperature thermochronometry of fault-related rocks provides an unprecedented window into the 105-106-yr record of San Andreas Fault-related deformation in the Mecca Hills and documents hematite deformation mechanisms that may be operative in other strike-slip faults world-wide.

  7. Heterogeneous slip and rupture models of the San Andreas fault zone based upon three-dimensional earthquake tomography

    Energy Technology Data Exchange (ETDEWEB)

    Foxall, William [Univ. of California, Berkeley, CA (United States)


    Crystal fault zones exhibit spatially heterogeneous slip behavior at all scales, slip being partitioned between stable frictional sliding, or fault creep, and unstable earthquake rupture. An understanding the mechanisms underlying slip segmentation is fundamental to research into fault dynamics and the physics of earthquake generation. This thesis investigates the influence that large-scale along-strike heterogeneity in fault zone lithology has on slip segmentation. Large-scale transitions from the stable block sliding of the Central 4D Creeping Section of the San Andreas, fault to the locked 1906 and 1857 earthquake segments takes place along the Loma Prieta and Parkfield sections of the fault, respectively, the transitions being accomplished in part by the generation of earthquakes in the magnitude range 6 (Parkfield) to 7 (Loma Prieta). Information on sub-surface lithology interpreted from the Loma Prieta and Parkfield three-dimensional crustal velocity models computed by Michelini (1991) is integrated with information on slip behavior provided by the distributions of earthquakes located using, the three-dimensional models and by surface creep data to study the relationships between large-scale lithological heterogeneity and slip segmentation along these two sections of the fault zone.

  8. Core Across the San Andreas Fault at SAFOD - Photographs, Physical Properties Data, and Core-Handling Procedures (United States)

    Kirschner, D. L.; Carpenter, B.; Keenan, T.; Sandusky, E.; Sone, H.; Ellsworth, B.; Hickman, S.; Weiland, C.; Zoback, M.


    Core samples were obtained that cross three faults of the San Andreas Fault Zone north of Parkfield, California, during the summer of 2007. The cored intervals were obtained by sidetracking off the SAFOD Main Hole that was rotary drilled across the San Andreas in 2005. The first cored interval targeted the pronounced lithologic boundary between the Salinian terrane and the Great Valley and Franciscan formations. Eleven meters of pebbly conglomerate (with minor amounts of fine sands and shale) were obtained from 3141 to 3152 m (measured depth, MD). The two conglomerate units are heavily fractured with many fractures having accommodated displacement. Within this cored interval, there is a ~1m zone with highly sheared, fine-grained material, possibly ultracataclasite in part. The second cored interval crosses a creeping segment of a fault that has been deforming the cemented casing of the adjacent Main Hole. This cored interval sampled the fault 100 m above a seismogenic patch of M2 repeating earthquakes. Thirteen meters of core were obtained across this fault from 3186 to 3199 m (MD). This fault, which is hosted primarily in siltstones and shales, contains a serpentinite body embedded in a highly sheared shale and serpentinite-bearing fault gouge unit. The third cored interval crosses a second creeping fault that has also been deforming the cemented casing of the Main Hole. This fault, which is the most rapidly shearing fault in the San Andreas fault zone based on casing deformation, contains multiple fine- grained clay-rich fault strands embedded in highly sheared shales and lesser deformed sandstones. Initial processing of the cores was carried out at the drill site. Each core came to the surface in 9 meter-long aluminum core barrels. These were cut into more manageable three-foot sections. The quarter-inch-thick aluminum liner of each section was cut and then split apart to reveal the 10 cm diameter cores. Depending on the fragility and porosity of the rock, the

  9. Scientific drilling into the San Andreas fault and site characterization research: Planning and coordination efforts. Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Zoback, M.D.


    The fundamental scientific issue addressed in this proposal, obtaining an improved understanding of the physical and chemical processes responsible for earthquakes along major fault zones, is clearly of global scientific interest. By sampling the San Andreas fault zone and making direct measurements of fault zone properties to 4.0 km at Parkfield they will be studying an active plate-boundary fault at a depth where aseismic creep and small earthquakes occur and where a number of the scientific questions associated with deeper fault zone drilling can begin to be addressed. Also, the technological challenges associated with drilling, coring, downhole measurements and borehole instrumentation that may eventually have to be faced in deeper drilling can first be addressed at moderate depth and temperature in the Parkfield hole. Throughout the planning process leading to the development of this proposal they have invited participation by scientists from around the world. As a result, the workshops and meetings they have held for this project have involved about 350 scientists and engineers from about a dozen countries.

  10. Deformation of Sedimentary Rock Across the San Andreas Fault Zone: Mesoscale and Microscale Structures Displayed in Core From SAFOD (United States)

    Chester, J. S.; Chester, F. M.; Kirschner, D. L.; Almeida, R.; Evans, J. P.; Guillemette, R. N.; Hickman, S.; Zoback, M.; Ellsworth, W.


    Sedimentary rocks captured in cores taken at the San Andreas Fault Observatory at Depth (SAFOD) provide an unparalleled sampling of deformation in the transition zone between creeping and locked segments of a major transform fault at 2.5-3.1 km vertical depth. These samples provide the unique opportunity to study deformation processes and the development of brittle structures within porous and granular rocks that have been subjected to variable loading rates and chemically reactive fluids while residing at the top of the seismogenic zone. The samples provide a transect from relatively undeformed host rock through highly fractured and sheared rock, and capture the two prominent zones of active, aseismic slip. Core recovery was almost complete. Wrap-around 1:1 map tracings of the outer surfaces of all cores characterize the lithology and mesoscale deformation. Cores from 3056-3067 m and 3141-3153 m measured depth (MD) sample moderately deformed rock at the western boundary of the fault zone. The cores display massive to finely laminated, pebbly arkosic sandstones with lesser amounts of fine-grained sandstone and siltstone. Numerous shear fractures and cm-thick cataclastic shear zones form a conjugate geometry indicating contraction at high angles to the San Andreas fault. Both intervals display minor faults that juxtapose different lithologies consistent with meters or greater of slip. Fracture density is variable but tends to increase with proximity to the minor faults. Cross-cutting relationships between shear fractures and cataclastic zones indicate a general progression from early faulting along thicker shear zones to later, more localized slip within shear zones and along fractures. Microstructures provide ample evidence for densification of the sandstones through grain-scale fracture and crushing, as well as fluid assisted processes of crack-sealing, dissolution-precipitation, and alteration-neocrystallization. Grain-scale features are consistent with these

  11. Long-term slip rate of the southern San Andreas Fault, from 10Be-26Al surface exposure dating of an offset alluvial fan

    Energy Technology Data Exchange (ETDEWEB)

    der Woerd, J v; Klinger, Y; Sieh, K; Tapponnier, P; Ryerson, F; M?riaux, A


    We determine the long-term slip rate of the southern San Andreas Fault in the southeastern Indio Hills using {sup 10}Be and {sup 26}Al isotopes to date an offset alluvial fan surface. Field mapping complemented with topographic data, air photos and satellite images allow to precisely determine piercing points across the fault zone that are used to measure an offset of 565 {+-} 80 m. A total of twenty-six quartz-rich cobbles from three different fan surfaces were collected and dated. The tight cluster of nuclide concentrations from 19 samples out of 20 from the offset fan surface implies a simple exposure history, negligible prior exposure and erosion, and yield an age of 35.5 {+-} 2.5 ka. The long-term slip rate of the San Andreas Fault south of Biskra Palms is thus 15.9 {+-} 3.4 mm/yr. This rate is about 10 mm/yr slower than geological (0-14 ka) and short-term geodetic estimates for this part of the San Andreas Fault implying changes in slip rate or in faulting behavior. This result puts new constraints on the slip rate of the San Jacinto and on the Eastern California Shear Zone for the last 35 ka. Our study shows that more sites along the major faults of southern California need to be targeted to better constrain the slip-rates over different time scales.

  12. Character and Implications of a Newly Identified Creeping Strand of the San Andreas fault NE of Salton Sea, Southern California (United States)

    Janecke, S. U.; Markowski, D.


    The overdue earthquake on the Coachella section, San Andreas fault (SAF), the model ShakeOut earthquake, and the conflict between cross-fault models involving the Extra fault array and mapped shortening in the Durmid Hill area motivate new analyses at the southern SAF tip. Geologic mapping, LiDAR, seismic reflection, magnetic and gravity datasets, and aerial photography confirm the existence of the East Shoreline strand (ESS) of the SAF southwest of the main trace of the SAF. We mapped the 15 km long ESS, in a band northeast side of the Salton Sea. Other data suggest that the ESS continues N to the latitude of the Mecca Hills, and is >35 km long. The ESS cuts and folds upper Holocene beds and appears to creep, based on discovery of large NW-striking cracks in modern beach deposits. The two traces of the SAF are parallel and ~0.5 to ~2.5 km apart. Groups of east, SE, and ENE-striking strike-slip cross-faults connect the master dextral faults of the SAF. There are few sinistral-normal faults that could be part of the Extra fault array. The 1-km wide ESS contains short, discontinuous traces of NW-striking dextral-oblique faults. These en-echelon faults bound steeply dipping Pleistocene beds, cut out section, parallel tight NW-trending folds, and produced growth folds. Beds commonly dip toward the ESS on both sides, in accord with persistent NE-SW shortening across the ESS. The dispersed fault-fold structural style of the ESS is due to decollements in faulted mud-rich Pliocene to Holocene sediment and ramps and flats along the strike-slip faults. A sheared ladder-like geometric model of the two master dextral strands of the SAF and their intervening cross-faults, best explains the field relationships and geophysical datasets. Contraction across >40 km2 of the southernmost SAF zone in the Durmid Hills suggest that interaction of active structures in the SAF zone may inhibit the nucleation of large earthquakes in this region. The ESS may cross the northern Coachella

  13. Geomorphology, denudation rates, and stream channel profiles reveal patterns of mountain building adjacent to the San Andreas fault in northern California, USA (United States)

    DeLong, Stephen B.; Hilley, George E.; Prentice, Carol S.; Crosby, Christopher J.; Yokelson, Intan N.


    Relative horizontal motion along strike-slip faults can build mountains when motion is oblique to the trend of the strike-slip boundary. The resulting contraction and uplift pose off-fault seismic hazards, which are often difficult to detect because of the poor vertical resolution of satellite geodesy and difficulty of locating offset datable landforms in active mountain ranges. Sparse geomorphic markers, topographic analyses, and measurement of denudation allow us to map spatiotemporal patterns of uplift along the northern San Andreas fault. Between Jenner and Mendocino, California, emergent marine terraces found southwest of the San Andreas fault record late Pleistocene uplift rates between 0.20 and 0.45 mm yr–1 along much of the coast. However, on the northeast side of the San Andreas fault, a zone of rapid uplift (0.6–1.0 mm yr–1) exists adjacent to the San Andreas fault, but rates decay northeastward as the coast becomes more distant from the San Andreas fault. A newly dated 4.5 Ma shallow-marine deposit located at ∼500 m above sea level (masl) adjacent to the San Andreas fault is warped down to just 150 masl 15 km northeast of the San Andreas fault, and it is exposed at just 60–110 masl to the west of the fault. Landscape denudation rates calculated from abundance of cosmogenic radionuclides in fluvial sediment northeast of, and adjacent to, the San Andreas fault are 0.16–0.29 mm yr–1, but they are only 0.03–0.07 mm yr–1 west of the fault. Basin-average channel steepness and the denudation rates can be used to infer the erosive properties of the underlying bedrock. Calibrated erosion rates can then be estimated across the entire landscape using the spatial distribution of channel steepness with these erosive properties. The lower-elevation areas of this landscape that show high channel steepness (and hence calibrated erosion rate) are distinct from higher-elevation areas with systematically lower channel steepness and denudation rates

  14. The ShakeOut scenario: A hypothetical Mw7.8 earthquake on the Southern San Andreas Fault (United States)

    Porter, K.; Jones, L.; Cox, D.; Goltz, J.; Hudnut, K.; Mileti, D.; Perry, S.; Ponti, D.; Reichle, M.; Rose, A.Z.; Scawthorn, C.R.; Seligson, H.A.; Shoaf, K.I.; Treiman, J.; Wein, A.


    In 2008, an earthquake-planning scenario document was released by the U.S. Geological Survey (USGS) and California Geological Survey that hypothesizes the occurrence and effects of a Mw7.8 earthquake on the southern San Andreas Fault. It was created by more than 300 scientists and engineers. Fault offsets reach 13 m and up to 8 m at lifeline crossings. Physics-based modeling was used to generate maps of shaking intensity, with peak ground velocities of 3 m/sec near the fault and exceeding 0.5 m/sec over 10,000 km2. A custom HAZUS??MH analysis and 18 special studies were performed to characterize the effects of the earthquake on the built environment. The scenario posits 1,800 deaths and 53,000 injuries requiring emergency room care. Approximately 1,600 fires are ignited, resulting in the destruction of 200 million square feet of the building stock, the equivalent of 133,000 single-family homes. Fire contributes $87 billion in property and business interruption loss, out of the total $191 billion in economic loss, with most of the rest coming from shakerelated building and content damage ($46 billion) and business interruption loss from water outages ($24 billion). Emergency response activities are depicted in detail, in an innovative grid showing activities versus time, a new format introduced in this study. ?? 2011, Earthquake Engineering Research Institute.

  15. Deep-water turbidites as Holocene earthquake proxies: the Cascadia subduction zone and Northern San Andreas Fault systems

    Directory of Open Access Journals (Sweden)

    J. E. Johnson


    Full Text Available New stratigraphic evidence from the Cascadia margin demonstrates that 13 earthquakes ruptured the margin from Vancouver Island to at least the California border following the catastrophic eruption of Mount Mazama. These 13 events have occurred with an average repeat time of ?? 600 years since the first post-Mazama event ?? 7500 years ago. The youngest event ?? 300 years ago probably coincides with widespread evidence of coastal subsidence and tsunami inundation in buried marshes along the Cascadia coast. We can extend the Holocene record to at least 9850 years, during which 18 events correlate along the same region. The pattern of repeat times is consistent with the pattern observed at most (but not all localities onshore, strengthening the contention that both were produced by plate-wide earthquakes. We also observe that the sequence of Holocene events in Cascadia may contain a repeating pattern, a tantalizing look at what may be the long-term behavior of a major fault system. Over the last ?? 7500 years, the pattern appears to have repeated at least three times, with the most recent A.D. 1700 event being the third of three events following a long interval of 845 years between events T4 and T5. This long interval is one that is also recognized in many of the coastal records, and may serve as an anchor point between the offshore and onshore records. Similar stratigraphic records are found in two piston cores and one box core from Noyo Channel, adjacent to the Northern San Andreas Fault, which show a cyclic record of turbidite beds, with thirty- one turbidite beds above a Holocene/.Pleistocene faunal «datum». Thus far, we have determined ages for 20 events including the uppermost 5 events from these cores. The uppermost event returns a «modern» age, which we interpret is likely the 1906 San Andreas earthquake. The penultimate event returns an intercept age of A.D. 1664 (2 ?? range 1505- 1822. The third event and fourth event

  16. Stratigraphic record of Pliocene-Pleistocene basin evolution and deformation within the Southern San Andreas Fault Zone, Mecca Hills, California (United States)

    McNabb, James C.; Dorsey, Rebecca J.; Housen, Bernard A.; Dimitroff, Cassidy W.; Messé, Graham T.


    A thick section of Pliocene-Pleistocene nonmarine sedimentary rocks exposed in the Mecca Hills, California, provides a record of fault-zone evolution along the Coachella Valley segment of the San Andreas fault (SAF). Geologic mapping, measured sections, detailed sedimentology, and paleomagnetic data document a 3-5 Myr history of deformation and sedimentation in this area. SW-side down offset on the Painted Canyon fault (PCF) starting 3.7 Ma resulted in deposition of the Mecca Conglomerate southwest of the fault. The lower member of the Palm Spring Formation accumulated across the PCF from 3.0 to 2.6 Ma during regional subsidence. SW-side up slip on the PCF and related transpressive deformation from 2.6 to 2.3 Ma created a time-transgressive angular unconformity between the lower and upper members of the Palm Spring Formation. The upper member accumulated in discrete fault-bounded depocenters until initiation of modern deformation, uplift, and basin inversion starting at 0.7 Ma. Some spatially restricted deposits can be attributed to the evolution of fault-zone geometric complexities. However, the deformation events at ca. 2.6 Ma and 0.7 Ma are recorded regionally along 80 km of the SAF through Coachella Valley, covering an area much larger than mapped fault-zone irregularities, and thus require regional explanations. We therefore conclude that late Cenozoic deformation and sedimentation along the SAF in Coachella Valley has been controlled by a combination of regional tectonic drivers and local deformation due to dextral slip through fault-zone complexities. We further propose a kinematic link between the 2.6-2.3 Ma angular unconformity and a previously documented but poorly dated reorganization of plate-boundary faults in the northern Gulf of California at 3.3-2.0 Ma. This analysis highlights the potential for high-precision chronologies in deformed terrestrial deposits to provide improved understanding of local- to regional-scale structural controls on basin

  17. A new perspective on the geometry of the San Andreas Fault in southern California and its relationship to lithospheric structure (United States)

    Fuis, Gary S.; Scheirer, Daniel S.; Langenheim, Victoria; Kohler, Monica D.


    The widely held perception that the San Andreas fault (SAF) is vertical or steeply dipping in most places in southern California may not be correct. From studies of potential‐field data, active‐source imaging, and seismicity, the dip of the SAF is significantly nonvertical in many locations. The direction of dip appears to change in a systematic way through the Transverse Ranges: moderately southwest (55°–75°) in the western bend of the SAF in the Transverse Ranges (Big Bend); vertical to steep in the Mojave Desert; and moderately northeast (37°–65°) in a region extending from San Bernardino to the Salton Sea, spanning the eastern bend of the SAF in the Transverse Ranges. The shape of the modeled SAF is crudely that of a propeller. If confirmed by further studies, the geometry of the modeled SAF would have important implications for tectonics and strong ground motions from SAF earthquakes. The SAF can be traced or projected through the crust to the north side of a well documented high‐velocity body (HVB) in the upper mantle beneath the Transverse Ranges. The north side of this HVB may be an extension of the plate boundary into the mantle, and the HVB would appear to be part of the Pacific plate.

  18. Basin geometry and cumulative offsets in the Eastern Transverse Ranges, southern California: Implications for transrotational deformation along the San Andreas fault system (United States)

    Langenheim, V.E.; Powell, R.E.


    The Eastern Transverse Ranges, adjacent to and southeast of the big left bend of the San Andreas fault, southern California, form a crustal block that has rotated clockwise in response to dextral shear within the San Andreas system. Previous studies have indicated a discrepancy between the measured magnitudes of left slip on through-going east-striking fault zones of the Eastern Transverse Ranges and those predicted by simple geometric models using paleomagnetically determined clockwise rotations of basalts distributed along the faults. To assess the magnitude and source of this discrepancy, we apply new gravity and magnetic data in combination with geologic data to better constrain cumulative fault offsets and to define basin structure for the block between the Pinto Mountain and Chiriaco fault zones. Estimates of offset from using the length of pull-apart basins developed within left-stepping strands of the sinistral faults are consistent with those derived by matching offset magnetic anomalies and bedrock patterns, indicating a cumulative offset of at most ???40 km. The upper limit of displacements constrained by the geophysical and geologic data overlaps with the lower limit of those predicted at the 95% confidence level by models of conservative slip located on margins of rigid rotating blocks and the clockwise rotation of the paleomagnetic vectors. Any discrepancy is likely resolved by internal deformation within the blocks, such as intense deformation adjacent to the San Andreas fault (that can account for the absence of basins there as predicted by rigid-block models) and linkage via subsidiary faults between the main faults. ?? 2009 Geological Society of America.

  19. Three-Dimensional Investigation of a 5 m Deflected Swale along the San Andreas Fault in the Carrizo Plain

    KAUST Repository

    Akciz, S. O.


    Topographic maps produced from Light Detection and Ranging (LiDAR) data are useful for paleoseismic and neotectonic research because they provide submeter representation of faulting-related surface features. Offset measurements of geomorphic features, made in the field or on a remotely sensed imagery, commonly assume a straight or smooth (i.e., undeflected) pre-earthquake geometry. Here, we present results from investigation of an ∼20 cm deep and >5 m wide swale with a sharp bend along the San Andreas fault (SAF) at the Bidart fan site in the Carrizo Plain, California. From analysis of LiDAR topography images and field measurements, the swale was initially interpreted as a channel tectonically offset ∼4:7 m. Our observations from exposures in four backhoe excavations and 25 hand-dug trenchettes show that even though a sharp bend in the swale coincides with the trace of the A.D. 1857 fault rupture, the swale formed after the 1857 earthquake and was not tectonically offset. Subtle fractures observed within a surficial gravel unit overlying the 1857 rupture trace are similar to fractures previously documented at the Phelan fan and LY4 paleoseismic sites 3 and 35 km northwest of Bidart fan, respectively. Collectively, the fractures suggest that a post-1857 moderate-magnitude earthquake caused ground cracking in the Carrizo and Cholame stretches of the SAF. Our observations emphasize the importance of excavation at key locations to validate remote and ground-based measurements, and we advocate more geomorphic characterization for each site if excavation is not possible.

  20. Long-Term Slip Rate on the Southern San Andreas Fault Determined by Th-230/U Dating of Pedogenic Carbonate. (United States)

    Fletcher, K. E.; Johnson, G.; Kendrick, K. J.; Hudnut, K. W.; Sharp, W. D.


    Determinations of long-term slip rates are limited, in part, by our ability to accurately estimate the age of offset landforms. U-series dating on pedogenic carbonate provides a relatively novel way of dating landforms, with strengths that complement more widely applied cosmogenic (CRN) techniques. We present new Th-230/U dates for pedogenic carbonate coatings on pebbles of the Biskra Palms fan, near Indio, California, which is offset by the southern San Andreas fault. Small, carefully chosen samples of dense pedogenic carbonate analyzed by mass spectrometry, have 3-10 ppm uranium and low common thorium (Th-232), making them highly favorable for U-series dating. Only minor corrections for initial Th-230 are necessary, and are made using Th-232 as an index isotope with propagation of uncertainties. Samples of early-formed carbonate collected from depths of about 2 m in fan soils typically consist of dense coatings 200-500 microns thick. Such coatings from 6 pebbles from 3 different locations within the fan yield apparent ages between 30 ± 2 ka and 46 ± 2 ka (all errors 2 sigma), with a median age of 38.4 ka (n= 11). Each age averages over the sampled interval of coating growth, hence the spread of ages reflects clast-to-clast variation in coating accumulation rates. All ages are therefore minimum ages for the stabilization of the fan because the time lag between stabilization and carbonate pedogenesis at Biskra Palms is, as yet, unknown. Sub-samples of individual clast-coatings yield ages in good agreement-- e.g., 45.0 ± 0.8 ka, 46.0 ± 1.8 ka, 44.8 ± 1.0 ka, 45.7 ± 0.9 ka (MSWD = 0.88), demonstrating closed U-Th systems. Van der Woerd et al (2006) reported an average CRN age of 35.5 ± 2.5 ka for the fan surface and an offset of 565 ± 80 m, for a slip rate of 15.9 ± 3.4 mm/a. Using their offset, and our oldest mean age of 45.3 ± 0.5 Ma (n=4, ages above) as the minimum landform age, we estimate a maximum slip rate of 12.5 ± 1.8 mm/a. This maximum average

  1. Space-time model for repeating earthquakes and analysis of recurrence intervals on the San Andreas Fault near Parkfield, California (United States)

    Nomura, Shunichi; Ogata, Yosihiko; Nadeau, Robert M.


    We propose a stochastic model for characteristically repeating earthquake sequences to estimate the spatiotemporal change in static stress loading rate. These earthquakes recur by a cyclic mechanism where stress at a hypocenter is accumulated by tectonic forces until an earthquake occurs that releases the accumulated stress to a basal level. Renewal processes are frequently used to describe this repeating earthquake mechanism. Variations in the rate of tectonic loading due to large earthquakes and aseismic slip transients, however, introduce nonstationary effects into the repeating mechanism that result in nonstationary trends in interevent times, particularly for smaller-magnitude repeating events which have shorter interevent times. These trends are also similar among repeating earthquake sites having similar hypocenters. Therefore, we incorporate space-time structure represented by cubic B-spline functions into the renewal model and estimate their coefficient parameters by maximizing the integrated likelihood in a Bayesian framework. We apply our model to 31 repeating earthquake sequences including 824 events on the Parkfield segment of the San Andreas Fault and estimate the spatiotemporal transition of the loading rate on this segment. The result gives us details of the change in tectonic loading caused by an aseismic slip transient in 1993, the 2004 Parkfield M6 earthquake, and other nearby or remote seismic activities. The degree of periodicity of repeating event recurrence intervals also shows spatial trends that are preserved in time even after the 2004 Parkfield earthquake when time scales are normalized with respect to the estimated loading rate.

  2. Locating non-volcanic tremor along the San Andreas Fault using a multiple array source imaging technique (United States)

    Ryberg, T.; Haberland, C.H.; Fuis, G.S.; Ellsworth, W.L.; Shelly, D.R.


    Non-volcanic tremor (NVT) has been observed at several subduction zones and at the San Andreas Fault (SAF). Tremor locations are commonly derived by cross-correlating envelope-transformed seismic traces in combination with source-scanning techniques. Recently, they have also been located by using relative relocations with master events, that is low-frequency earthquakes that are part of the tremor; locations are derived by conventional traveltime-based methods. Here we present a method to locate the sources of NVT using an imaging approach for multiple array data. The performance of the method is checked with synthetic tests and the relocation of earthquakes. We also applied the method to tremor occurring near Cholame, California. A set of small-aperture arrays (i.e. an array consisting of arrays) installed around Cholame provided the data set for this study. We observed several tremor episodes and located tremor sources in the vicinity of SAF. During individual tremor episodes, we observed a systematic change of source location, indicating rapid migration of the tremor source along SAF. ?? 2010 The Authors Geophysical Journal International ?? 2010 RAS.

  3. Ground Motion Prediction for M7+ scenarios on the San Andreas Fault using the Virtual Earthquake Approach (United States)

    Denolle, M.; Dunham, E. M.; Prieto, G.; Beroza, G. C.


    There is no clearer example of the increase in hazard due to prolonged and amplified shaking in sedimentary, than the case of Mexico City in the 1985 Michoacan earthquake. It is critically important to identify what other cities might be susceptible to similar basin amplification effects. Physics-based simulations in 3D crustal structure can be used to model and anticipate those effects, but they rely on our knowledge of the complexity of the medium. We propose a parallel approach to validate ground motion simulations using the ambient seismic field. We compute the Earth's impulse response combining the ambient seismic field and coda-wave enforcing causality and symmetry constraints. We correct the surface impulse responses to account for the source depth, mechanism and duration using a 1D approximation of the local surface-wave excitation. We call the new responses virtual earthquakes. We validate the ground motion predicted from the virtual earthquakes against moderate earthquakes in southern California. We then combine temporary seismic stations on the southern San Andreas Fault and extend the point source approximation of the Virtual Earthquake Approach to model finite kinematic ruptures. We confirm the coupling between source directivity and amplification in downtown Los Angeles seen in simulations.

  4. Using surface creep rate to infer fraction locked for sections of the San Andreas fault system in northern California from alignment array and GPS data (United States)

    Lienkaemper, James J.; McFarland, Forrest S.; Simpson, Robert W.; Caskey, S. John


    Surface creep rate, observed along five branches of the dextral San Andreas fault system in northern California, varies considerably from one section to the next, indicating that so too may the depth at which the faults are locked. We model locking on 29 fault sections using each section’s mean long‐term creep rate and the consensus values of fault width and geologic slip rate. Surface creep rate observations from 111 short‐range alignment and trilateration arrays and 48 near‐fault, Global Positioning System station pairs are used to estimate depth of creep, assuming an elastic half‐space model and adjusting depth of creep iteratively by trial and error to match the creep observations along fault sections. Fault sections are delineated either by geometric discontinuities between them or by distinctly different creeping behaviors. We remove transient rate changes associated with five large (M≥5.5) regional earthquakes. Estimates of fraction locked, the ratio of moment accumulation rate to loading rate, on each section of the fault system provide a uniform means to inform source parameters relevant to seismic‐hazard assessment. From its mean creep rates, we infer the main branch (the San Andreas fault) ranges from only 20%±10% locked on its central creeping section to 99%–100% on the north coast. From mean accumulation rates, we infer that four urban faults appear to have accumulated enough seismic moment to produce major earthquakes: the northern Calaveras (M 6.8), Hayward (M 6.8), Rodgers Creek (M 7.1), and Green Valley (M 7.1). The latter three faults are nearing or past their mean recurrence interval.

  5. A 15 year catalog of more than 1 million low-frequency earthquakes: Tracking tremor and slip along the deep San Andreas Fault (United States)

    Shelly, David R.


    Low-frequency earthquakes (LFEs) are small, rapidly recurring slip events that occur on the deep extensions of some major faults. Their collective activation is often observed as a semicontinuous signal known as tectonic (or nonvolcanic) tremor. This manuscript presents a catalog of more than 1 million LFEs detected along the central San Andreas Fault from 2001 to 2016. These events have been detected via a multichannel matched-filter search, cross-correlating waveform templates representing 88 different LFE families with continuous seismic data. Together, these source locations span nearly 150 km along the central San Andreas Fault, ranging in depth from 16 to 30 km. This accumulating catalog has been the source for numerous studies examining the behavior of these LFE sources and the inferred slip behavior of the deep fault. The relatively high temporal and spatial resolutions of the catalog have provided new insights into properties such as tremor migration, recurrence, and triggering by static and dynamic stress perturbations. Collectively, these characteristics are inferred to reflect a very weak fault likely under near-lithostatic fluid pressure, yet the physical processes controlling the stuttering rupture observed as tremor and LFE signals remain poorly understood. This paper aims to document the LFE catalog assembly process and associated caveats, while also updating earlier observations and inferred physical constraints. The catalog itself accompanies this manuscript as part of the electronic supplement, with the goal of providing a useful resource for continued future investigations.

  6. Chemical controls on fault behavior: weakening of serpentinite sheared against quartz-bearing rocks and its significance for fault creep in the San Andreas system (United States)

    Moore, Diane E.; Lockner, David A.


    The serpentinized ultramafic rocks found in many plate-tectonic settings commonly are juxtaposed against crustal rocks along faults, and the chemical contrast between the rock types potentially could influence the mechanical behavior of such faults. To investigate this possibility, we conducted triaxial experiments under hydrothermal conditions (200-350°C), shearing serpentinite gouge between forcing blocks of granite or quartzite. In an ultramafic chemical environment, the coefficient of friction, µ, of lizardite and antigorite serpentinite is 0.5-0.6, and µ increases with increasing temperature over the tested range. However, when either lizardite or antigorite serpentinite is sheared against granite or quartzite, strength is reduced to µ ~ 0.3, with the greatest strength reductions at the highest temperatures (temperature weakening) and slowest shearing rates (velocity strengthening). The weakening is attributed to a solution-transfer process that is promoted by the enhanced solubility of serpentine in pore fluids whose chemistry has been modified by interaction with the quartzose wall rocks. The operation of this process will promote aseismic slip (creep) along serpentinite-bearing crustal faults at otherwise seismogenic depths. During short-term experiments serpentine minerals reprecipitate in low-stress areas, whereas in longer experiments new Mg-rich phyllosilicates crystallize in response to metasomatic exchanges across the serpentinite-crustal rock contact. Long-term shear of serpentinite against crustal rocks will cause the metasomatic mineral assemblages, which may include extremely weak minerals such as saponite or talc, to play an increasingly important role in the mechanical behavior of the fault. Our results may explain the distribution of creep on faults in the San Andreas system.

  7. Experimental constraints on the relationship between clay abundance, clay fabric, and frictional behavior for the Central Deforming Zone of the San Andreas Fault (United States)

    Wojatschke, Jasmaria; Scuderi, Marco M.; Warr, Laurence N.; Carpenter, Brett M.; Saffer, Demian; Marone, Chris


    The presence of smectite (saponite) in fault gouge from the Central Deforming Zone of the San Andreas Fault at Parkfield, CA has been linked to low mechanical strength and aseismic slip. However, the precise relationship between clay mineral structure, fabric development, fault strength, and the stability of frictional sliding is not well understood. We address these questions through the integration of laboratory friction tests and FIB-SEM analysis of fault rock recovered from the San Andreas Fault Observatory at Depth (SAFOD) borehole. Intact fault rock was compared with experimentally sheared fault gouge and different proportions of either quartz clasts or SAFOD clasts extracted from the sample. Nano-textural measurements show the development of localized clay particle alignment along shear folia developed within synthetic gouges; such slip planes have multiples of random distribution (MRD) values of 3.0-4.9. The MRD values measured are higher than previous estimates (MRD 1.5) that show lower degrees of shear localization and clay alignment averaged over larger volumes. The intact fault rock exhibits less well-developed nano-clay fabrics than the experimentally sheared materials, and MRD values decrease with smectite content. We show that the abundance, strength, and shape of clasts all influence fabric evolution via strain localization: quartz clasts yield more strongly developed clay fabrics than serpentine-dominated SAFOD clasts. Our results suggest that (1) both clay abundance and the development of nano-scale fabrics play a role in fault zone weakening and (2) aseismic creep is promoted by slip along clay shears with >20 wt % smectite content and MRD values ≥2.7.

  8. The transtensional offshore portion of the northern San Andreas fault: Fault zone geometry, late Pleistocene to Holocene sediment deposition, shallow deformation patterns, and asymmetric basin growth (United States)

    Beeson, Jeffrey W.; Johnson, Samuel Y.; Goldfinger, Chris


    We mapped an ~120 km offshore portion of the northern San Andreas fault (SAF) between Point Arena and Point Delgada using closely spaced seismic reflection profiles (1605 km), high-resolution multibeam bathymetry (~1600 km2), and marine magnetic data. This new data set documents SAF location and continuity, associated tectonic geomorphology, shallow stratigraphy, and deformation. Variable deformation patterns in the generally narrow (∼1 km wide) fault zone are largely associated with fault trend and with transtensional and transpressional fault bends.We divide this unique transtensional portion of the offshore SAF into six sections along and adjacent to the SAF based on fault trend, deformation styles, seismic stratigraphy, and seafloor bathymetry. In the southern region of the study area, the SAF includes a 10-km-long zone characterized by two active parallel fault strands. Slip transfer and long-term straightening of the fault trace in this zone are likely leading to transfer of a slice of the Pacific plate to the North American plate. The SAF in the northern region of the survey area passes through two sharp fault bends (∼9°, right stepping, and ∼8°, left stepping), resulting in both an asymmetric lazy Z–shape sedimentary basin (Noyo basin) and an uplifted rocky shoal (Tolo Bank). Seismic stratigraphic sequences and unconformities within the Noyo basin correlate with the previous 4 major Quaternary sea-level lowstands and record basin tilting of ∼0.6°/100 k.y. Migration of the basin depocenter indicates a lateral slip rate on the SAF of 10–19 mm/yr for the past 350 k.y.Data collected west of the SAF on the south flank of Cape Mendocino are inconsistent with the presence of an offshore fault strand that connects the SAF with the Mendocino Triple Junction. Instead, we suggest that the SAF previously mapped onshore at Point Delgada continues onshore northward and transitions to the King Range thrust.

  9. Displacement and dynamic weakening processes in smectite-rich gouge from the Central Deforming Zone of the San Andreas Fault (United States)

    French, M. E.; Kitajima, H.; Chester, J. S.; Chester, F. M.; Hirose, T.


    The strength of clay-rich gouge from the Central Deforming Zone (CDZ) of the San Andreas Fault (SAF) was measured using a high-speed rotary shear apparatus to evaluate the potential for unstable slip along the creeping segment of the SAF. Wet and dry gouge was sheared at 0.1-1.3 m/s, 0.5-1.5 MPa normal stress, and 1-20 m displacement. CDZ gouge is weaker wet than dry and exhibits displacement strengthening to peak friction followed by weakening to steady state strength that decreases with increasing velocity. A clay foliation (Unit 2) develops from the initial microstructure (Unit 1) during the first 1.5 m of slip coincident with increasing strength. Subsequent weakening occurs during shear within Unit 2, and subsequently with development of a localized foliated slip zone (Unit 4) and fluidized material (Unit 3). Displacement and dynamic weakening result from slip along clay foliation assisted by shear-heating pressurization of pore fluid in wet gouge and additional grain-size reduction and possible clay dehydration in dry gouge. Peak strength is proportional to normal stress, but steady state strength is insensitive to normal stress probably because pore pressure approaches the normal stress. As such, CDZ gouge is weak at coseismic rates relative to interseismic creep strength. The potential for sustaining rupture propagation into the CDZ from an adjacent seismic segment is sensitive to the relationship used to extrapolate the critical weakening displacement from experimental to in situ conditions. Rupture propagation from a microseismic patch within the CDZ is unlikely, but sustained propagation from a large earthquake (e.g., Parkfield event) may be possible.

  10. Microstructures from the San Andreas Fault Observatory at Depth (SAFOD) Phase 3 Cores (United States)

    Clancy White, Joseph; Kennedy, Lori A.


    Core retrieved from SAFOD Phase 3 drilling has been examined in three locations: (1) with the Salinian Terrane near its contact with the presumed Great Valley sequence (Hole E-Run 1-Section 4 & 6); (2) proximal to the ‘10480' fault zone with which are associated casing deformation and seismic aftershocks indicative of active faulting (Hole G-Run-1-Section 2 & Hole G-Run 2-Section 3); and (3) adjacent to the ‘10830' fault zone in the centre of the damage zone identified in Phase 2 drilling (Hole G-Run 4-Section 2). The sampling locations translate to an across-strike distance from outside the damage to its centre of approximately 125 metres, and a change in current depth from 2610 m to 2685m. The Salinian Terrane material (E14, E16) comprises coarse-grained quartz and perthitic feldspar clasts that locally form slightly foliated cataclasite. The matrix is commonly chloritic with very fine-grained aggregates and zones of quartz and/or feldspar. There are both corroded clasts, particularly of quartz, and globular infillings of calcite with sutured contacts. Foliated siltstone-shale cataclasites (G12, G23) at the edge of the damage zone close to the ‘10480' fault zone exhibit brecciation and cataclasis at different scales; deformation is episodic as there are distinct overprinting relationships. The fine-grained matrix exhibits a strong SPO of phyllosilicates and cryptocrystalline quartz (form parallel to the cataclastic foliation, suggestive of fault parallel hydraulic fracture. Coarser grained phyllosilicate zones develop C-S type fabrics with dextral displacement sense. Oxidation within deformation bands is variable, though very well developed in the late, coarse fragment cataclasites. The latter zones can exhibit well-rounded clasts separated by thin foliae of a pressure solution foliation. Sheared siltstone/sandstone from within central portion of the damage zone approximately 7m across strike from the ‘10830' fault zone extensive evidence of fluid

  11. Coseismic brecciation at fault stepovers and transient fluid pathways in a mid-crustal San Andreas analogue: The Pofadder Shear Zone, Namibia and South Africa (United States)

    Melosh, B. L.; Rowe, C. D.; Gerbi, C. C.


    Fluid transport along faults is important throughout the seismic cycle due to the effects on fault strength. Rheological boundaries in the crust such as the quartz brittle-plastic transition coincide with permeability changes, and play an important role in controlling fluid distribution. Here we present a newly recognized mechanism for fluid migration through the brittle-plastic transition in an ancient San Andreas Fault analogue: The Pofadder Shear Zone in Namibia and South Africa. Breccias formed in elongate pods during the passage of an earthquake rupture through a fault stepover. These breccias form subvertical fluid pathways (perpendicular to the slip direction). Over time, many overprinting or adjacent ruptures could have allowed fluid migration over a large (~ kms) scale, facilitating fluid flow through a low porosity region of the crust. These pathways were subsequently closed during breccia compaction by crystal plastic flow, facilitated by the presence of fluids. Thus, fluid migration within and across the brittle-plastic transitional zone is time and rate dependent and can both cause fault weakening and strengthening. We observed breccias formed in slip events with displacements between ~1-15 cm, consistent with small to moderate magnitude earthquakes and/or tectonic tremor, which occurs at similar depths in the San Andreas Fault. In addition to providing a new way of identifying paleo-seismic slip in the rock record, these observations may help explain co- post-seismic fluid advection in mid-crustal faults. This process of local brecciation in stepovers may be the origin of cryptic geophysical signals such as tremor bursts in continental faults.

  12. Slip rates and spatially variable creep on faults of the northern San Andreas system inferred through Bayesian inversion of Global Positioning System data (United States)

    Murray, Jessica R.; Minson, Sarah E.; Svarc, Jerry L.


    Fault creep, depending on its rate and spatial extent, is thought to reduce earthquake hazard by releasing tectonic strain aseismically. We use Bayesian inversion and a newly expanded GPS data set to infer the deep slip rates below assigned locking depths on the San Andreas, Maacama, and Bartlett Springs Faults of Northern California and, for the latter two, the spatially variable interseismic creep rate above the locking depth. We estimate deep slip rates of 21.5 ± 0.5, 13.1 ± 0.8, and 7.5 ± 0.7 mm/yr below 16 km, 9 km, and 13 km on the San Andreas, Maacama, and Bartlett Springs Faults, respectively. We infer that on average the Bartlett Springs fault creeps from the Earth's surface to 13 km depth, and below 5 km the creep rate approaches the deep slip rate. This implies that microseismicity may extend below the locking depth; however, we cannot rule out the presence of locked patches in the seismogenic zone that could generate moderate earthquakes. Our estimated Maacama creep rate, while comparable to the inferred deep slip rate at the Earth's surface, decreases with depth, implying a slip deficit exists. The Maacama deep slip rate estimate, 13.1 mm/yr, exceeds long-term geologic slip rate estimates, perhaps due to distributed off-fault strain or the presence of multiple active fault strands. While our creep rate estimates are relatively insensitive to choice of model locking depth, insufficient independent information regarding locking depths is a source of epistemic uncertainty that impacts deep slip rate estimates.

  13. Pliocene transpressional modification of depositional basins by convergent thrusting adjacent to the "Big Bend" of the San Andreas fault: An example from Lockwood Valley, southern California (United States)

    Kellogg, K.S.; Minor, S.A.


    The "Big Bend" of the San Andreas fault in the western Transverse Ranges of southern California is a left stepping flexure in the dextral fault system and has long been recognized as a zone of relatively high transpression compared to adjacent regions. The Lockwood Valley region, just south of the Big Bend, underwent a profound change in early Pliocene time (???5 Ma) from basin deposition to contraction, accompanied by widespread folding and thrusting. This change followed the recently determined initiation of opening of the northern Gulf of California and movement along the southern San Andreas fault at about 6.1 Ma, with the concomitant formation of the Big Bend. Lockwood Valley occupies a 6-km-wide, fault-bounded structural basin in which converging blocks of Paleoproterozoic and Cretaceous crystalline basement and upper Oligocene and lower Miocene sedimentary rocks (Plush Ranch Formation) were thrust over Miocene and Pliocene basin-fill sedimentary rocks (in ascending order, Caliente Formation, Lockwood Clay, and Quatal Formation). All the pre-Quatal sedimentary rocks and most of the Pliocene Quatal Formation were deposited during a mid-Tertiary period of regional transtension in a crustal block that underwent little clockwise vertical-axis rotation as compared to crustal blocks to the south. Ensuing Pliocene and Quaternary transpression in the Big Bend region began during deposition of the poorly dated Quatal Formation and was marked by four converging thrust systems, which decreased the areal extent of the sedimentary basin and formed the present Lockwood Valley structural basin. None of the thrusts appears presently active. Estimated shortening across the center of the basin was about 30 percent. The fortnerly defined eastern Big Pine fault, now interpreted to be two separate, oppositely directed, contractional reverse or thrust faults, marks the northwestern structural boundary of Lockwood Valley. The complex geometry of the Lockwood Valley basin is similar

  14. Pliocene transpressional modification of depositional basins by convergent thrusting adjacent to the ``Big Bend'' of the San Andreas fault: An example from Lockwood Valley, southern California (United States)

    Kellogg, Karl S.; Minor, Scott A.


    The "Big Bend" of the San Andreas fault in the western Transverse Ranges of southern California is a left stepping flexure in the dextral fault system and has long been recognized as a zone of relatively high transpression compared to adjacent regions. The Lockwood Valley region, just south of the Big Bend, underwent a profound change in early Pliocene time (˜5 Ma) from basin deposition to contraction, accompanied by widespread folding and thrusting. This change followed the recently determined initiation of opening of the northern Gulf of California and movement along the southern San Andreas fault at about 6.1 Ma, with the concomitant formation of the Big Bend. Lockwood Valley occupies a 6-km-wide, fault-bounded structural basin in which converging blocks of Paleoproterozoic and Cretaceous crystalline basement and upper Oligocene and lower Miocene sedimentary rocks (Plush Ranch Formation) were thrust over Miocene and Pliocene basin-fill sedimentary rocks (in ascending order, Caliente Formation, Lockwood Clay, and Quatal Formation). All the pre-Quatal sedimentary rocks and most of the Pliocene Quatal Formation were deposited during a mid-Tertiary period of regional transtension in a crustal block that underwent little clockwise vertical-axis rotation as compared to crustal blocks to the south. Ensuing Pliocene and Quaternary transpression in the Big Bend region began during deposition of the poorly dated Quatal Formation and was marked by four converging thrust systems, which decreased the areal extent of the sedimentary basin and formed the present Lockwood Valley structural basin. None of the thrusts appears presently active. Estimated shortening across the center of the basin was about 30 percent. The formerly defined eastern Big Pine fault, now interpreted to be two separate, oppositely directed, contractional reverse or thrust faults, marks the northwestern structural boundary of Lockwood Valley. The complex geometry of the Lockwood Valley basin is similar

  15. Ground-rupturing earthquakes on the northern Big Bend of the San Andreas Fault, California, 800 A.D. to Present (United States)

    Scharer, Katherine M.; Weldon, Ray; Biasi, Glenn; Streig, Ashley; Fumal, Thomas E.


    Paleoseismic data on the timing of ground-rupturing earthquakes constrain the recurrence behavior of active faults and can provide insight on the rupture history of a fault if earthquakes dated at neighboring sites overlap in age and are considered correlative. This study presents the evidence and ages for 11 earthquakes that occurred along the Big Bend section of the southern San Andreas Fault at the Frazier Mountain paleoseismic site. The most recent earthquake to rupture the site was the Mw7.7–7.9 Fort Tejon earthquake of 1857. We use over 30 trench excavations to document the structural and sedimentological evolution of a small pull-apart basin that has been repeatedly faulted and folded by ground-rupturing earthquakes. A sedimentation rate of 0.4 cm/yr and abundant organic material for radiocarbon dating contribute to a record that is considered complete since 800 A.D. and includes 10 paleoearthquakes. Earthquakes have ruptured this location on average every ~100 years over the last 1200 years, but individual intervals range from ~22 to 186 years. The coefficient of variation of the length of time between earthquakes (0.7) indicates quasiperiodic behavior, similar to other sites along the southern San Andreas Fault. Comparison with the earthquake chronology at neighboring sites along the fault indicates that only one other 1857-size earthquake could have occurred since 1350 A.D., and since 800 A.D., the Big Bend and Mojave sections have ruptured together at most 50% of the time in Mw ≥ 7.3 earthquakes.

  16. Isotopic evidence for the infiltration of mantle and metamorphic CO2-H2O fluids from below in faulted rocks from the San Andreas Fault System

    Energy Technology Data Exchange (ETDEWEB)

    Pili, E.; Kennedy, B.M.; Conrad, M.E.; Gratier, J.-P.


    To characterize the origin of the fluids involved in the San Andreas Fault (SAF) system, we carried out an isotope study of exhumed faulted rocks from deformation zones, vein fillings and their hosts and the fluid inclusions associated with these materials. Samples were collected from segments along the SAF system selected to provide a depth profile from upper to lower crust. In all, 75 samples from various structures and lithologies from 13 localities were analyzed for noble gas, carbon, and oxygen isotope compositions. Fluid inclusions exhibit helium isotope ratios ({sup 3}He/{sup 4}He) of 0.1-2.5 times the ratio in air, indicating that past fluids percolating through the SAF system contained mantle helium contributions of at least 35%, similar to what has been measured in present-day ground waters associated with the fault (Kennedy et al., 1997). Calcite is the predominant vein mineral and is a common accessory mineral in deformation zones. A systematic variation of C- and O-isotope compositions of carbonates from veins, deformation zones and their hosts suggests percolation by external fluids of similar compositions and origin with the amount of fluid infiltration increasing from host rocks to vein to deformation zones. The isotopic trend observed for carbonates in veins and deformation zones follows that shown by carbonates in host limestones, marbles, and other host rocks, increasing with increasing contribution of deep metamorphic crustal volatiles. At each crustal level, the composition of the infiltrating fluids is thus buffered by deeper metamorphic sources. A negative correlation between calcite {delta}{sup 13}C and fluid inclusion {sup 3}He/{sup 4}He is consistent with a mantle origin for a fraction of the infiltrating CO{sub 2}. Noble gas and stable isotope systematics show consistent evidence for the involvement of mantle-derived fluids combined with infiltration of deep metamorphic H{sub 2}O and CO{sub 2} in faulting, supporting the involvement of

  17. Structure of the San Bernardino Basin Along Two Seismic Transects: Rialto-Colton Fault to the San Andreas Fault and Along the I-215 Freeway (I-10 to SR30) (United States)

    Catchings, R.D.; Rymer, M.J.; Goldman, M.R.; Gandhok, G.; Steedman, C.E.


    show internal consistency and consistency with other existing geophysical data. Collectively, the data suggest that the I-215 freeway trends along the faulted edge of a pull-apart basin, within a zone where the principal slip of the San Jacinto Fault is transferred to the San Andreas Fault. Because the I-215 freeway trends at low angles to these flower-structure faults, both primary and numerous secondary faults are apparent between the I-10 exchange and State Road-30, suggesting that much of the 8-km-long segment of the I-215 freeway could experience movement along primary or secondary faults.

  18. Crustal strain near the Big Bend of the San Andreas Fault: analysis of the Los Padres-Tehachapi Trilateration Networks, California (United States)

    Eberhart-Phillips, D.; Lisowski, M.


    In the region of the Los Padres-Tehachapi geodetic network, the San Andreas fault (SAF) changes its orientation by over 30?? from N40??W, close to that predicted by plate motion for a transform boundary, to N73??W. The strain orientation near the SAF is consistent with right-lateral shear along the fault, with maximum shear rate of 0.38??0.01??rad/yr at N63??W. In contrast, away from the SAF the strain orientations on both sides of the fault are consistent with the plate motion direction, with maximum shear rate of 0.19??0.01??rad/yr at N44??W. The best fitting Garlock fault model had computed left-lateral slip rate of 11??2mm/yr below 10km. Buried left-lateral slip of 15??6mm/yr on the Big Pine fault, within the Western Transverse Ranges, provides significant reduction in line length residuals; however, deformation there may be more complicated than a single vertical fault. A subhorizontal detachment on the southern side of the SAF cannot be well constrained by these data. -from Authors

  19. Tremor reveals stress shadowing, deep postseismic creep, and depth-dependent slip recurrence on the lower-crustal San Andreas fault near Parkfield (United States)

    Shelly, David R.; Johnson, Kaj M.


    The 2003 magnitude 6.5 San Simeon and the 2004 magnitude 6.0 Parkfield earthquakes induced small, but significant, static stress changes in the lower crust on the central San Andreas fault, where recently detected tectonic tremor sources provide new constraints on deep fault creep processes. We find that these earthquakes affect tremor rates very differently, consistent with their differing transferred static shear stresses. The San Simeon event appears to have cast a "stress shadow" north of Parkfield, where tremor activity was stifled for 3-6 weeks. In contrast, the 2004 Parkfield earthquake dramatically increased tremor activity rates both north and south of Parkfield, allowing us to track deep postseismic slip. Following this event, rates initially increased by up to two orders of magnitude for the relatively shallow tremor sources closest to the rupture, with activity in some sources persisting above background rates for more than a year. We also observe strong depth dependence in tremor recurrence patterns, with shallower sources generally exhibiting larger, less-frequent bursts, possibly signaling a transition toward steady creep with increasing temperature and depth. Copyright 2011 by the American Geophysical Union.

  20. High-resolution deep tectonic tremor locations beneath the San Andreas Fault near Cholame, California, using the double-pair double-difference location method (United States)

    Guo, Hao; Zhang, Haijiang; Nadeau, Robert M.; Peng, Zhigang


    We determine high-precision deep tectonic tremor locations beneath the San Andreas Fault (SAF) near Cholame, California, region by using a newly developed double-pair double-difference location method and a new 3-D Vs model. Compared to the previous results, newly determined tremor locations are more consistent with known low-frequency earthquake locations and are more concentrated along the SAF. New tremor locations near Cholame show clear contrast in the predominant depth of the tremor activity across the SAF and also show contrasts in the degree of periodic behavior both along and across the SAF. They collectively define a very special tremor generation region (VSTR) near the intersection corner between the SAF and the adjacent San Juan Fault (SJF). In the VSTR, new locations reveal some isolated tremor clusters, which may occur on multiple deep fault patches. For these isolated clusters, some are closer to the SAF and some are closer to the SJF, implying that both the SAF and SJF may extend to the ductile lower crust. Possible interaction between the SAF and SJF in the lower crust beneath the VSTR, combined with the trapped high-pressure fluids, may explain the strong tremor activity, the isolated tremor clusters, and the characteristic tremor occurrence patterns and depth distributions in this region.

  1. Crustal strain near the big bend of the San Andreas fault: Analysis of the Los Padres-Tehachapi trilateration networks, California

    Energy Technology Data Exchange (ETDEWEB)

    Eberhart-Phillips, D.; Lisowski, M. (Geological Survey, Menlo Park, CA (United States)); Zoback, M.D. (Stanford Univ., CA (United States))


    In the region of the Los Padres-Tehachapi geodetic network, the San Andreas fault (SAF) changes its orientation by over 30{degree} from N 40{degree}W, close to that predicted by plate motion for a transform boundary, to N 73{degree}W. The strain orientation near the SAF is consistent with right-lateral shear along the fault, with maximum shear rate of 0.38 {plus minus} 0.01 {mu}rad/yr at N 63{degree}W. In contrast, away from the SAF the strain orientations on both sides of the fault are consistent with the plate motion direction, with maximum shear rate of 0.19 {plus minus} 0.01 {mu}rad/yr at N 44{degree}W. The strain rate does not drop off rapidly away from the fault, and thus the area is fit by either a broad shear zone below the SAF or a single fault with a relatively deep locking depth. The fit to the line length data is poor for locking depth d less than 25 km. For d of 25 km a buried slip rate of 30 {plus minus} 6 mm/yr is estimated. The authors also estimated buried slip for models that include the Garlock and Big Pine faults, in addition to the SAF. Slip rates on other faults are poorly constrained by the Los Padres-Tehachapi network. The best fitting Garlock fault model had computed left-lateral slip rate of 11 {plus minus} 2 mm/yr below 10 km. Buried left-lateral slip of 15 {plus minus} 6 mm/yr on the Big Pine fault, within the Western Transverse Ranges, provides significant reduction in line length residuals; however, deformation there may be more complicated than a single vertical fault. A subhorizontal detachment on the southern side of the SAF cannot be well constrained by these data. The authors investigated the location of the SAF and found that a vertical fault below the surface trace fits the data much better than either a dipping fault zone located south of the surface trace.

  2. High Resolution Interseismic Velocity Model of the San Andreas Fault System From a Joint Inversion of GPS and InSAR Data (United States)

    Tong, X.; Sandwell, D. T.; Smith-Konter, B. R.


    Geodetic observations along the plate boundary have been used to constrain moment accumulation rate and stressing rate of active faults during the interseismic period. We compared 4 of these interseismic velocity models of the San Andreas Fault System (SAFS) based on GPS observations [Mccaffrey, 2005; Meade and Hager, 2005; Smith-Konter and Sandwell, 2009; Zeng and Shen, 2010]. The standard deviations of these 4 models are larger north of the Bay Area, near the Creeping segment in Central California, and along the San Jacinto fault and the Eastern California Shear Zone in Southern California. A coherence spectrum analysis indicates relatively high correlation among the 4 models at longer wavelengths (>15-40 km), with lower correlation at shorter wavelengths. To improve the short-wavelength accuracy of our GPS-derived interseismic velocity model, we integrated InSAR observations, initially from ALOS ascending data (spanning from the middle of 2006 to the end of 2010, totaling more than 1100 interferograms), using a Sum/Remove/Filter/Restore (SURF) approach. The final InSAR line-of-site (LOS) data match the point GPS observations with a mean absolute deviation of 1.3 mm/yr. These new LOS data were subsampled according to the magnitude of the strain rate and are available at We use this high-resolution InSAR LOS data, combined with geological slip rate constraints and secular GPS vectors to invert for the fault slip rate of 50 active fault segments in California using a 3-D viscoelastic earthquake cycle model. This model simulates interseismic deformation resulting from deep slip on faults extending from a prescribed locking depth to the bottom of an elastic plate which overlies the viscoelastic half-space [Smith-Konter and Sandwell, 2009]. The linear least squares problem is solved by Singular Value Decomposition (SVD) and the uncertainties are estimated using covariance matrix of the solution parameters. In this

  3. S-wave triggering of tremor beneath the Parkfield, California, section of the San Andreas fault by the 2011 Tohoku, Japan earthquake: observations and theory (United States)

    Hill, David P.; Peng, Zhigang; Shelly, David R.; Aiken, Chastity


    The dynamic stresses that are associated with the energetic seismic waves generated by the Mw 9.0 Tohoku earthquake off the northeast coast of Japan triggered bursts of tectonic tremor beneath the Parkfield section of the San Andreas fault (SAF) at an epicentral distance of ∼8200  km. The onset of tremor begins midway through the ∼100‐s‐period S‐wave arrival, with a minor burst coinciding with the SHSH arrival, as recorded on the nearby broadband seismic station PKD. A more pronounced burst coincides with the Love arrival, followed by a series of impulsive tremor bursts apparently modulated by the 20‐ to 30‐s‐period Rayleigh wave. The triggered tremor was located at depths between 20 and 30 km beneath the surface trace of the fault, with the burst coincident with the S wave centered beneath the fault 30 km northwest of Parkfield. Most of the subsequent activity, including the tremor coincident with the SHSH arrival, was concentrated beneath a stretch of the fault extending from 10 to 40 km southeast of Parkfield. The seismic waves from the Tohoku epicenter form a horizontal incidence angle of ∼14°, with respect to the local strike of the SAF. Computed peak dynamic Coulomb stresses on the fault at tremor depths are in the 0.7–10 kPa range. The apparent modulation of tremor bursts by the small, strike‐parallel Rayleigh‐wave stresses (∼0.7  kPa) is likely enabled by pore pressure variations driven by the Rayleigh‐wave dilatational stress. These results are consistent with the strike‐parallel dynamic stresses (δτs) associated with the S, SHSH, and surface‐wave phases triggering small increments of dextral slip on the fault with a low friction (μ∼0.2). The vertical dynamic stresses δτd do not trigger tremor with vertical or oblique slip under this simple Coulomb failure model.

  4. Spatiotemporal evolution of surface creep in the Parkfield region of the San Andreas Fault (1993-2004) from synthetic aperture radar (United States)

    de Michele, M.; Raucoules, D.; Rolandone, F.; Briole, P.; Salichon, J.; Lemoine, A.; Aochi, H.


    The Parkfield section of the San Andreas Fault (SAF) is defined as a transitional portion of the fault between slip-release behavior types in the creeping section of the SAF to the northwest and the apparently locked section to the southeast. The Parkfield section is characterized by complex frictional fault behavior because it represents a transition zone from aseismic creep to stick-slip regime. At least six historic earthquakes of M w ~ 6 have occurred in this area in 1881, 1901, 1922, 1934, 1966, and 2004. It was observed in the 2004 M w 6.0 Parkfield earthquake that ~ 70% of the total (coseismic and postseismic) moment release occurred aseismically. To understand the SAF behavior in this area, it is of particular interest to measure and analyze, not only the spatial evolution of the surface displacement in this area, but also its evolution over time. Using radar data acquired by the European Space Agency's European Remote Sensing (ERS1-2) satellites, we constructed descending interferograms and retrieved time series of surface displacements along the central SAF for the decade preceding the 2004 Parkfield earthquake. We focus on characterizing the space and time evolution of surface creep in the Parkfield and Cholame sections. The spatial pattern of the interseismic displacement rate indicates that tectonic strain was not uniformly distributed along the strike of the fault between 1993 and 2004. Our data indicate not only a decrease in the creep rate from the Parkfield section to south of Highway-46 from 1.4 ± 0.3 cm/yr to 0.6 ± 0.3 cm/yr, but also a small but significant creep-rate increase in the Cholame section to 0.2 ± 0.1 cm/yr. The evidence for episodic creep in the Cholame section of the SAF south-east of Parkfield is in contrast with previously published interpretations of GPS and trilateration data. The Cholame section of the SAF merits close monitoring because it was likely the nucleation site of the 1857 Fort Tejón earthquake and because it has

  5. Volatile fluxes through the Big Bend section of the San Andreas Fault, California: helium and carbon-dioxide systematics (United States)

    Kulongoski, Justin T.; Hilton, David R.; Barry, Peter H.; Esser, Bradley K.; Hillegonds, Darren; Belitz, Kenneth


    To investigate the source of volatiles and their relationship to the San Andreas Fault System (SAFS), 18 groundwater samples were collected from wells near the Big Bend section of the SAFS in southern California and analyzed for helium and carbon abundance and isotopes. Concentrations of 4He, corrected for air-bubble entrainment, vary from 4.15 to 62.7 (× 10− 8) cm3 STP g− 1 H2O. 3He/4He ratios vary from 0.09 to 3.52 RA (where RA = air 3He/4He), consistent with up to 44% mantle helium in samples. A subset of 10 samples was analyzed for the major volatile phase (CO2) — the hypothesized carrier phase of the helium in the mantle–crust system: CO2/3He ratios vary from 0.614 to 142 (× 1011), and δ13C (CO2) values vary from − 21.5 to − 11.9‰ (vs. PDB). 3He/4He ratios and CO2 concentrations are highest in the wells located in the Mil Potrero and Cuddy valleys adjacent to the SAFS. The elevated 3He/4He ratios are interpreted to be a consequence of a mantle volatile flux though the SAFS diluted by radiogenic He produced in the crust. Samples with the highest 3He/4He ratios also had the lowest CO2/3He ratios. The combined helium isotope, He–CO2 elemental relationships, and δ13C (CO2) values of the groundwater volatiles reveal a mixture of mantle and deep crustal (metamorphic) fluid origins. The flux of fluids into the seismogenic zone at high hydrostatic pressure may cause fault rupture, and transfer volatiles into the shallow crust. We calculate an upward fluid flow rate of 147 mm a− 1 along the SAFS, up to 37 times higher than previous estimates (Kennedy et al., 1997). However, using newly identified characteristics of the SAFS, we calculate a total flux of 3He along the SAFS of 7.4 × 103 cm3 STP a− 1 (0.33 mol 3He a− 1), and a CO2 flux of 1.5 × 1013 cm3STP a− 1 (6.6 × 108 mol a− 1), ~ 1% of previous estimates. Lower fluxes along the Big Bend section of the SAFS suggest that the flux of mantle volatiles alone is insufficient to cause the

  6. Evolution of the Gorda Escarpment, San Andreas fault and Mendocino triple junction from multichannel seismic data collected across the northern Vizcaino block, offshore northern California (United States)

    Godfrey, N.J.; Meltzer, A.S.; Klemperer, S.L.; Trehu, A.M.; Leitner, B.; Clarke, S.H.; Ondrus, A.


    The Gorda Escarpment is a north facing scarp immediately south of the Mendocino transform fault (the Gorda/Juan de Fuca-Pacific plate boundary) between 126??W and the Mendocino triple junction. It elevates the seafloor at the northern edge of the Vizcaino block, part of the Pacific plate, ??? 1.5 km above the seafloor of the Gorda/Juan de Fuca plate to the north. Stratigraphy interpreted from multichannel seismic data across and close to the Gorda Escarpment suggests that the escarpment is a relatively recent pop-up feature caused by north-south compression across the plate boundary. Close to 126??W. the Vizcaino block acoustic basement shallows and is overlain by sediments that thin north toward the Gorda Escarpment. These sediments are tilted south and truncated at the seafloor. By contrast, in a localized region at the eastern end of the Gorda Escarpment, close to the Mendocino triple junction, the top of acoustic basement dips north and is overlain by a 2-km-thick wedge of pre-11 Ma sedimentary rocks that thickens north, toward the Gorda Escarpment. This wedge of sediments is restricted to the northeast corner of the Vizcaino block. Unless the wedge of sediments was a preexisting feature on the Vizcaino block before it was transferred from the North American to the Pacific plate, the strong spatial correlation between the sedimentary wedge and the triple junction suggests the entire Vizcaino block, with the San Andreas at its eastern boundary, has been part of the Pacific plate since significantly before 11 Ma.

  7. Using a modified time-reverse imaging technique to locate low-frequency earthquakes on the San Andreas Fault near Cholame, California (United States)

    Horstmann, Tobias; Harrington, Rebecca M.; Cochran, Elizabeth S.


    We present a new method to locate low-frequency earthquakes (LFEs) within tectonic tremor episodes based on time-reverse imaging techniques. The modified time-reverse imaging technique presented here is the first method that locates individual LFEs within tremor episodes within 5 km uncertainty without relying on high-amplitude P-wave arrivals and that produces similar hypocentral locations to methods that locate events by stacking hundreds of LFEs without having to assume event co-location. In contrast to classic time-reverse imaging algorithms, we implement a modification to the method that searches for phase coherence over a short time period rather than identifying the maximum amplitude of a superpositioned wavefield. The method is independent of amplitude and can help constrain event origin time. The method uses individual LFE origin times, but does not rely on a priori information on LFE templates and families.We apply the method to locate 34 individual LFEs within tremor episodes that occur between 2010 and 2011 on the San Andreas Fault, near Cholame, California. Individual LFE location accuracies range from 2.6 to 5 km horizontally and 4.8 km vertically. Other methods that have been able to locate individual LFEs with accuracy of less than 5 km have mainly used large-amplitude events where a P-phase arrival can be identified. The method described here has the potential to locate a larger number of individual low-amplitude events with only the S-phase arrival. Location accuracy is controlled by the velocity model resolution and the wavelength of the dominant energy of the signal. Location results are also dependent on the number of stations used and are negligibly correlated with other factors such as the maximum gap in azimuthal coverage, source–station distance and signal-to-noise ratio.

  8. Evidence for Cyclic Brittle-Ductile Deformation from San Andreas Fault Observatory at Depth (SAFOD) Phase 3 Cores (United States)

    White, J. C.; Kennedy, L.


    Microstructural development in core retrieved from SAFOD Phase 3 drilling has been examined in three locations utilizing light, scanning electron (SEM) and transmission electron microscopy (TEM): (1) within the Salinian Terrane near its contact with the presumed Great Valley sequence (Hole E-Run 1-Section 4 & 6); (2) proximal to the Southwest Deformation Zone (SDZ) with which are associated casing deformation and seismic aftershocks indicative of active faulting (Hole G-Run-1-Section 2 & Hole G-Run 2-Section 3); and (3) within the Central Deformation Zone (CDZ) in the centre of the damage zone identified in Phase 2 drilling (Hole G-Run 4-Section 2). The sampling locations translate to an across-strike distance from outside the damage zone to its centre of approximately 125 meters, and a change in current measured depth from 2610 m to 2685m. Common to all cores are: (1) a significant fractional volume (fluid flux in the form of stress-induced dissolution seams (pressure solution), grain precipitation and veining; and (3) complex, non-systematically varying phyllosilicate intergrowths (illite, muscovite, phengite, chlorite). The Salinian terrane material (E14, E16) comprises coarse-grained quartz and perthitic feldspar clasts that locally form slightly foliated cataclasite. The matrix is commonly chloritic with very fine-grained aggregates and zones of quartz and/or feldspar. Microbrecciation is ubiquitous. There are both fluid-corroded clasts, particularly of quartz, and globular infillings of calcite with sutured contacts. Quartz and feldspar grains are coated by chlorite. Amorphous silica and secondary Ti-Fe oxides occur within cataclasite. Foliated siltstone-shale cataclasites (G12, G23) at the edge of the damage zone close to the SDZ exhibit brecciation and cataclasis at different scales; deformation is episodic as there are distinct overprinting relationships. The fine-grained matrix exhibits a strong SPO of phyllosilicates and cryptocrystalline quartz (damage

  9. Analysis of nonvolcanic tremor on the San Andreas Fault near Parkfield, CA using U.S. Geological Survey Parkfield Seismic Array (United States)

    Fletcher, Jon B.; Baker, Lawrence M.


    Reports by Nadeau and Dolenc (2005) that tremor had been detected near Cholame Valley spawned an effort to use UPSAR (U. S. Geological Survey Parkfield Seismic Array) to study characteristics of tremor. UPSAR was modified to record three channels of velocity at 40–50 sps continuously in January 2005 and ran for about 1 month, during which time we recorded numerous episodes of tremor. One tremor, on 21 January at 0728, was recorded with particularly high signal levels as well as another episode 3 days later. Both events were very emergent, had a frequency content between 2 and 8 Hz, and had numerous high-amplitude, short-duration arrivals within the tremor signal. Here using the first episode as an example, we discuss an analysis procedure, which yields azimuth and apparent velocity of the tremor at UPSAR. We then provide locations for both tremor episodes. The emphasis here is how the tremor episode evolves. Twelve stations were operating at the time of recording. Slowness of arrivals was determined using cross correlation of pairs of stations; the same method used in analyzing the main shock data from 28 September 2004. A feature of this analysis is that 20 s of the time series were used at a time to calculate correlation; the longer windows resulted in more consistent estimates of slowness, but lower peak correlations. These values of correlation (peaks of about 0.25), however, are similar to that obtained for the S wave of a microearthquake. Observed peaks in slowness were traced back to source locations assumed to lie on the San Andreas fault. Our inferred locations for the two tremor events cluster near the locations of previously observed tremor, south of the Cholame Valley. Tremor source depths are in the 14–24 km range, which is below the seismogenic brittle zone, but above the Moho. Estimates of error do not preclude locations below the Moho, however. The tremor signal is very emergent but contains packets that are several times larger than the

  10. Lake level observations to detect crustal tilt: San Andreas Lake, California, 1979-1989

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, R.J.; Johnston, M.J.S.; Myren, G.D. (Geological Survey, Menlo Park, CA (USA)); Murray, T. (Cascades Volcano Observatory, Vancouver, WA (USA))


    A pair precision lake level gauging stations, installed in 1978, have been monitoring differential crustal uplift (crustal tilt) at San Andreas lake, California, near the suspected epicenter on the San Andreas fault of the M = 8.3, 1906 San Francisco earthquake. The stations are installed in the lake with a 4.2 km station separation parallel to the San Andreas fault. The gauging stations use quartz pressure transducers that are capable of detecting intermediate to long-term vertical displacements greater than 0.4 mm relative to a fluid surface. Differencing data from the two sites reduces the noise contributed by atmospheric pressure, temperature, and density changes, and isolates the relative elevation changes between the ends of the lake. At periods less than 20 minutes, the differenced data are dominated by lake seiches which have a fundamental mode at a period of 13 {plus minus} 0.3 minutes. These seiche harmonics can be filtered or predicted and removed from the data. Wind shear, typically lasting several days, can generate apparent short term tilt of the lake and large seiche amplitudes. The tilt noise power spectrum obtained from these data decreases by about 15 dB/decade of frequency. Monthly averages of the data between 1979-1989 indicate a tilt rate of 0.02 {plus minus} 0.08 microradians/yr (down S34{degree}E). No measurable horizontal tilt has apparently occurred in this region of the San Andreas fault during the last decade, however, measurements of trilateration networks show this region to be undergoing a horizontal strain of 0.6 {plus minus} 0.2 {mu}strain/yr.

  11. Coulomb stress interactions among M≥5.9 earthquakes in the Gorda deformation zone and on the Mendocino Fracture Zone, Cascadia megathrust, and northern San Andreas fault (United States)

    Rollins, John C.; Stein, Ross S.


    The Gorda deformation zone, a 50,000 km2 area of diffuse shear and rotation offshore northernmost California, has been the site of 20 M ≥ 5.9 earthquakes on four different fault orientations since 1976, including four M ≥ 7 shocks. This is the highest rate of large earthquakes in the contiguous United States. We calculate that the source faults of six recent M ≥ 5.9 earthquakes had experienced ≥0.6 bar Coulomb stress increases imparted by earthquakes that struck less than 9 months beforehand. Control tests indicate that ≥0.6 bar Coulomb stress interactions between M ≥ 5.9 earthquakes separated by Mw = 7.3 Trinidad earthquake are consistent with the locations of M ≥ 5.9 earthquakes in the Gorda zone until at least 1995, as well as earthquakes on the Mendocino Fault Zone in 1994 and 2000. Coulomb stress changes imparted by the 1980 earthquake are also consistent with its distinct elbow-shaped aftershock pattern. From these observations, we derive generalized static stress interactions among right-lateral, left-lateral and thrust faults near triple junctions.

  12. Long-term deformation driven by small ambient tectonic stresses and strong oscillating tidal within Enceladus with analogy to rock behavior near the San Andreas Fault (United States)

    Sleep, Norman H.


    Strong tidal stresses brought much of the icy shell of Enceladus into frictional failure at past times of high orbital eccentricity. The frictional behavior of shallow terrestrial rock exposed to repeated episodes of strong seismic waves provides analogy. Frictional failure produces cracks that lower the shear modulus. Seismic regolith develops where the shear modulus increases linearly with depth. Imposed peak strains barely cause frictional failure within self-organized regolith. With regard to Enceladus, eccentricity could continue to build up in the past since little anelastic strain, and hence tidal dissipation occurred within the self-organized regolith and within the underlying cold ice. A frictional instability analogous to the formation of weak major faults on the Earth likely occurred once the regolith was many kilometers thick. The effective coefficient of friction dropped to low levels along major faults within the deep cold ice. Tidal dissipation on these faults heated the ice starting thermal convention within the South Polar Terrain. Once thermal buoyancy produced stresses, the oscillating stresses from tides nonlinearly enhanced the rate of tectonic convection. Warm ice that dissipates tides now exists within Enceladus. The eccentricity will likely decrease and the object will then freeze.

  13. Detecting Significant Stress Drop Variations in Large Micro-Earthquake Datasets: A Comparison Between a Convergent Step-Over in the San Andreas Fault and the Ventura Thrust Fault System, Southern California (United States)

    Goebel, T. H. W.; Hauksson, E.; Plesch, A.; Shaw, J. H.


    A key parameter in engineering seismology and earthquake physics is seismic stress drop, which describes the relative amount of high-frequency energy radiation at the source. To identify regions with potentially significant stress drop variations, we perform a comparative analysis of source parameters in the greater San Gorgonio Pass (SGP) and Ventura basin (VB) in southern California. The identification of physical stress drop variations is complicated by large data scatter as a result of attenuation, limited recording bandwidth and imprecise modeling assumptions. In light of the inherently high uncertainties in single stress drop measurements, we follow the strategy of stacking large numbers of source spectra thereby enhancing the resolution of our method. We analyze more than 6000 high-quality waveforms between 2000 and 2014, and compute seismic moments, corner frequencies and stress drops. Significant variations in stress drop estimates exist within the SGP area. Moreover, the SGP also exhibits systematically higher stress drops than VB and shows more scatter. We demonstrate that the higher scatter in SGP is not a generic artifact of our method but an expression of differences in underlying source processes. Our results suggest that higher differential stresses, which can be deduced from larger focal depth and more thrust faulting, may only be of secondary importance for stress drop variations. Instead, the general degree of stress field heterogeneity and strain localization may influence stress drops more strongly, so that more localized faulting and homogeneous stress fields favor lower stress drops. In addition, higher loading rates, for example, across the VB potentially result in stress drop reduction whereas slow loading rates on local fault segments within the SGP region result in anomalously high stress drop estimates. Our results show that crustal and fault properties systematically influence earthquake stress drops of small and large events and should

  14. Geophysical Surveys of the San Andreas and Crystal Springs Reservoir System Including Seismic-Reflection Profiles and Swath Bathymetry, San Mateo County, California (United States)

    Finlayson, David P.; Triezenberg, Peter J.; Hart, Patrick E.


    This report describes geophysical data acquired by the U.S. Geological Survey (USGS) in San Andreas Reservoir and Upper and Lower Crystal Springs Reservoirs, San Mateo County, California, as part of an effort to refine knowledge of the location of traces of the San Andreas Fault within the reservoir system and to provide improved reservoir bathymetry for estimates of reservoir water volume. The surveys were conducted by the Western Coastal and Marine Geology (WCMG) Team of the USGS for the San Francisco Public Utilities Commission (SFPUC). The data were acquired in three separate surveys: (1) in June 2007, personnel from WCMG completed a three-day survey of San Andreas Reservoir, collecting approximately 50 km of high-resolution Chirp subbottom seismic-reflection data; (2) in November 2007, WCMG conducted a swath-bathymetry survey of San Andreas reservoir; and finally (3) in April 2008, WCMG conducted a swath-bathymetry survey of both the upper and lower Crystal Springs Reservoir system. Top of PageFor more information, contact David Finlayson.

  15. Pleistocene Brawley and Ocotillo Formations: Evidence for initial strike-slip deformation along the San Felipe and San Jacinto fault zonez, Southern California (United States)

    Kirby, S.M.; Janecke, S.U.; Dorsey, R.J.; Housen, B.A.; Langenheim, V.E.; McDougall, K.A.; Steeley, A.N.


    We examine the Pleistocene tectonic reorganization of the Pacific-North American plate boundary in the Salton Trough of southern California with an integrated approach that includes basin analysis, magnetostratigraphy, and geologic mapping of upper Pliocene to Pleistocene sedimentary rocks in the San Felipe Hills. These deposits preserve the earliest sedimentary record of movement on the San Felipe and San Jacinto fault zones that replaced and deactivated the late Cenozoic West Salton detachment fault. Sandstone and mudstone of the Brawley Formation accumulated between ???1.1 and ???0.6-0.5 Ma in a delta on the margin of an arid Pleistocene lake, which received sediment from alluvial fans of the Ocotillo Formation to the west-southwest. Our analysis indicates that the Ocotillo and Brawley formations prograded abruptly to the east-northeast across a former mud-dominated perennial lake (Borrego Formation) at ???1.1 Ma in response to initiation of the dextral-oblique San Felipe fault zone. The ???25-km-long San Felipe anticline initiated at about the same time and produced an intrabasinal basement-cored high within the San Felipe-Borrego basin that is recorded by progressive unconformities on its north and south limbs. A disconformity at the base of the Brawley Formation in the eastern San Felipe Hills probably records initiation and early blind slip at the southeast tip of the Clark strand of the San Jacinto fault zone. Our data are consistent with abrupt and nearly synchronous inception of the San Jacinto and San Felipe fault zones southwest of the southern San Andreas fault in the early Pleistocene during a pronounced southwestward broadening of the San Andreas fault zone. The current contractional geometry of the San Jacinto fault zone developed after ???0.5-0.6 Ma during a second, less significant change in structural style. ?? 2007 by The University of Chicago. All rights reserved.

  16. Calidad de fresa variedad San Andreas producida con vermicompost en invernadero


    Ramos García, Alondra


    Una alternativa para reducir el impacto negativo de las actividades agropecuarias es la utilización de vermicompost. El objetivo del presente trabajo fue evaluar el efecto del vermicompost como fertilizante líquido y como sustrato sobre la calidad de la fresa (Fragaria x ananassa Duch.) variedad San Andreas, bajo condiciones de invernadero. Se evaluaron dos sustratos: suelo y una mezcla de suelo y vermicompost. Se aplicaron cuatro tratamientos de fertilización líquida: 1) Soluc...

  17. Scientific drilling into the San Andreas Fault Zone (United States)

    Zoback, Mark; Hickman, Stephen; Ellsworth, William


    This year, the world has faced energetic and destructive earthquakes almost every month. In January, an M = 7.0 event rocked Haiti, killing an estimated 230,000 people. In February, an M = 8.8 earthquake and tsunami claimed over 500 lives and caused billions of dollars of damage in Chile. Fatal earthquakes also occurred in Turkey in March and in China and Mexico in April.

  18. How Faults Shape the Earth. (United States)

    Bykerk-Kauffman, Ann


    Presents fault activity with an emphasis on earthquakes and changes in continent shapes. Identifies three types of fault movement: normal, reverse, and strike faults. Discusses the seismic gap theory, plate tectonics, and the principle of superposition. Vignettes portray fault movement, and the locations of the San Andreas fault and epicenters of…

  19. Ambient Noise Tomography of Southern California Images Dipping San Andreas-Parallel Structure and Low-Velocity Salton Trough Mantle (United States)

    Barak, S.; Klemperer, S. L.; Lawrence, J. F.


    Ambient noise tomography (ANT) images the entire crust but does not depend on the spatial and temporal distribution of events. Our ANT high-resolution 3D velocity model of southern California uses 849 broadband stations, vastly more than previous studies, and four years of data, 1997-1998, 2007, and 2011, chosen to include our own broadband Salton Seismic Imaging Project, a 40-station transect across the Salton Trough, as well as other campaign stations in both Mexico and the U.S.A., and permanent stations. Our shear-wave model has 0.05° x 0.05° lateral and 1 km vertical blocks. We used the Harvard Community Velocity Model (CVM-H) as the initial model for the inversion. We show significant differences relative to the CVM-H model, especially in the lower crust and upper mantle. We observe prominent low-velocity anomalies in the upper mantle under the Salton Buttes and Cerro Prieto geothermal fields, indicating high-temperatures and possibly partial-melt. Similar low-velocity zones have been previously observed along the Gulf of California. We also observe vertical to gradually dipping lateral velocity contrasts in the lower crust under the southern part of the San Andreas Fault. The east to northeast dip may represent crustal fabric sheared by movement of the Pacific plate under the North American plate prior to the initiation of transform motion.

  20. Faults--Offshore of San Francisco Map Area, California (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for faults for the geologic and geomorphic map of the Offshore San Francisco map area, California. The vector data file is included...

  1. Faults--Offshore of San Gregorio Map Area, California (United States)

    U.S. Geological Survey, Department of the Interior — This part of SIM 3306 presents data for the faults for the geologic and geomorphic map (see sheet 10, SIM 3306) of the Offshore of San Gregorio map area, California....

  2. La Poésie sans frontières d’Andrea Moorhead

    Directory of Open Access Journals (Sweden)

    André Ughetto


    Full Text Available L’auteur met à jour la façon dont l’Américaine Andrea Moorhead donne à la langue française ce qu’elle se procure en elle : non les joliesses dont celle-ci est capable, mais la possibilité d’y effectuer un « voyage invisible ». Il suggère qu’Andrea Moorhead ose peut-être en français ce qu’elle se refuserait d’écrire en anglais en naviguant sur les énigmes de la langue. Son ardente quête la porte au-delà d’elle-même, ainsi que le laisse entendre le recueil de sa correspondance avec Joseph Bonenfant, Entre nous la neige.

  3. Fortnightly modulation of San Andreas tremor and low-frequency earthquakes (United States)

    Van Der Elst, Nicholas; Delorey, Andrew; Shelly, David R.; Johnson, Paul


    Earth tides modulate tremor and low-frequency earthquakes (LFEs) on faults in the vicinity of the brittle−ductile (seismic−aseismic) transition. The response to the tidal stress carries otherwise inaccessible information about fault strength and rheology. Here, we analyze the LFE response to the fortnightly tide, which modulates the amplitude of the daily tidal stress over a 14-d cycle. LFE rate is highest during the waxing fortnightly tide, with LFEs most strongly promoted when the daily stress exceeds the previous peak stress by the widest margin. This pattern implies a threshold failure process, with slip initiated when stress exceeds the local fault strength. Variations in sensitivity to the fortnightly modulation may reflect the degree of stress concentration on LFE-producing brittle asperities embedded within an otherwise aseismic fault.

  4. How fault evolution changes strain partitioning and fault slip rates in Southern California: Results from geodynamic modeling (United States)

    Ye, Jiyang; Liu, Mian


    In Southern California, the Pacific-North America relative plate motion is accommodated by the complex southern San Andreas Fault system that includes many young faults (western Transverse Ranges and along the dextral faults across the Mojave Desert, where numerous damaging earthquakes occurred in recent years.

  5. Near Surface Structure of the Frijoles Strand of the San Gregorio Fault, Point Año Nuevo, San Mateo County, California, from Seismic Imaging (United States)

    Campbell, L.; Catchings, R. D.; Rymer, M. J.; Goldman, M.; Weber, G. E.


    The San Gregorio Fault Zone (SGFZ) is one of the major faults of the San Andreas Fault (SAF) system in the San Francisco Bay region of California. The SGFZ is nearly 200 km long, trends subparallel to the SAF, and is located primarily offshore with two exceptions- between Point Año Nuevo and San Gregorio Beach and between Pillar Point and Moss Beach. It has a total width of 2 to 3 km and is comprised of seven known fault strands with Quaternary activity, five of which also demonstrate late Holocene activity. The fault is clearly a potential source of significant earthquakes and has been assigned a maximum likely magnitude of 7.3. To better understand the structure, geometry, and shallow-depth P-wave velocities associated with the SGFZ, we acquired a 585-m-long, high-resolution, combined seismic reflection and refraction profile across the Frijoles strand of the SGFZ at Point Año Nuevo State Park. Both P- and S-wave data were acquired, but here we present only the P-wave data. We used two 60-channel Geometrics RX60 seismographs and 120 40-Hz single-element geophones connected via cable to record Betsy Seisgun seismic sources (shots). Both shots and geophones were approximately co-located and spaced at 5-m intervals along the profile, with the shots offset laterally from the geophones by 1 m. We measured first-arrival refractions from all shots and geophones to develop a seismic refraction tomography velocity model of the upper 70 m. P-wave velocities range from about 600 m/s near the surface to more than 2400 m/s at 70 m depth. We used the refraction tomography image to infer the depth to the top of the groundwater table on the basis of the 1500 m/s velocity contour. The image suggests that the depth, along the profile, to the top of groundwater varies by about 18 m, with greater depth on the west side of the fault. At about 46 m depth, a 60- to 80-m-wide, low-velocity zone, which is consistent with faulting, is observed southwest of the Frijoles strand of the

  6. Investigation of late Pleistocene and Holocene activity in the San Gregorio fault zone on the continental slope north of Monterey Canyon, offshore central California (United States)

    Maier, Katherine L.; Paull, Charles K.; Brothers, Daniel; Caress, David W.; McGann, Mary; Lundsten, Eve M.; Anderson, Krystle; Gwiazda, Roberto


    We provide an extensive high‐resolution geophysical, sediment core, and radiocarbon dataset to address late Pleistocene and Holocene fault activity of the San Gregorio fault zone (SGFZ), offshore central California. The SGFZ occurs primarily offshore in the San Andreas fault system and has been accommodating dextral strike‐slip motion between the Pacific and North American plates since the mid‐Miocene. Our study focuses on the SGFZ where it has been mapped through the continental slope north of Monterey Canyon. From 2009 to 2015, the Monterey Bay Aquarium Research Institute collected high‐resolution multibeam bathymetry and chirp sub‐bottom profiles using an autonomous underwater vehicle (AUV). Targeted samples were collected using a remotely operated vehicle (ROV) to provide radiocarbon age constraints. We integrate the high‐resolution geophysical data with radiocarbon dates to reveal Pleistocene seismic horizons vertically offset less than 5 m on nearly vertical faults. These faults are buried by continuous reflections deposited after ∼17.5  ka and likely following erosion during the last sea‐level lowstand ∼21  ka, bracketing the age of faulting to ∼32–21  ka. Clearly faulted horizons are only detected in a small area where mass wasting exhumed older strata to within ∼25  m of the seafloor. The lack of clearly faulted Holocene deposits and possible highly distributed faulting in the study area are consistent with previous interpretations that late Pleistocene and Holocene activity along the SGFZ may decrease to the south. This study illustrates the complexity of the SGFZ, offshore central California, and demonstrates the utility of very high‐resolution data from combined AUV (geophysical)–ROV (seabed sampling) surveys in offshore studies of fault activity.

  7. The Fateful Rift: The San Andreas Fault in the Modern Mind. (United States)

    Percy, Walker


    Claims that modern science is radically incoherent and that this incoherence lies within the practice of science. Details the work of the scientist and philosopher Charles Sanders Pierce, expounding on the difference between Rene Descartes' dualistic philosophy and Pierce's triadic view. Concludes with a brief description of the human existence.…

  8. Electrical conductivity images of active and fossil fault zones


    Oliver Ritter; A. Hoffmann-Rothe; P. A. Bedrosian; Ute Weckmann; V. Haak;  ;  


    We compare recent magnetotelluric investigations of four large fault systems: (i) the actively deforming, ocean-continent interplate San Andreas Fault (SAF), (ii) the actively deforming, continent-continent interplate Dead Sea Transform (DST), (iii) the currently inactive, trench-linked intraplate West Fault (WF) in northern Chile, and (iv) the Waterberg Fault/Omaruru Lineament (WF/OL) in Namibia, a fossilized intraplate shear zone formed during early Proterozoic continental collision. These ...

  9. Recent deformation on the San Diego Trough and San Pedro Basin fault systems, offshore Southern California: Assessing evidence for fault system connectivity. (United States)

    Bormann, J. M.; Kent, G. M.; Driscoll, N. W.; Harding, A. J.


    The seismic hazard posed by offshore faults for coastal communities in Southern California is poorly understood and may be considerable, especially when these communities are located near long faults that have the ability to produce large earthquakes. The San Diego Trough fault (SDTF) and San Pedro Basin fault (SPBF) systems are active northwest striking, right-lateral faults in the Inner California Borderland that extend offshore between San Diego and Los Angeles. Recent work shows that the SDTF slip rate accounts for 25% of the 6-8 mm/yr of deformation accommodated by the offshore fault network, and seismic reflection data suggest that these two fault zones may be one continuous structure. Here, we use recently acquired CHIRP, high-resolution multichannel seismic (MCS) reflection, and multibeam bathymetric data in combination with USGS and industry MCS profiles to characterize recent deformation on the SDTF and SPBF zones and to evaluate the potential for an end-to-end rupture that spans both fault systems. The SDTF offsets young sediments at the seafloor for 130 km between the US/Mexico border and Avalon Knoll. The northern SPBF has robust geomorphic expression and offsets the seafloor in the Santa Monica Basin. The southern SPBF lies within a 25-km gap between high-resolution MCS surveys. Although there does appear to be a through-going fault at depth in industry MCS profiles, the low vertical resolution of these data inhibits our ability to confirm recent slip on the southern SPBF. Empirical scaling relationships indicate that a 200-km-long rupture of the SDTF and its southern extension, the Bahia Soledad fault, could produce a M7.7 earthquake. If the SDTF and the SPBF are linked, the length of the combined fault increases to >270 km. This may allow ruptures initiating on the SDTF to propagate within 25 km of the Los Angeles Basin. At present, the paleoseismic histories of the faults are unknown. We present new observations from CHIRP and coring surveys at

  10. Recent faulting in the Gulf of Santa Catalina: San Diego to Dana Point (United States)

    Ryan, H.F.; Legg, M.R.; Conrad, J.E.; Sliter, R.W.


    We interpret seismic-reflection profiles to determine the location and offset mode of Quaternary offshore faults beneath the Gulf of Santa Catalina in the inner California Continental Borderland. These faults are primarily northwest-trending, right-lateral, strike-slip faults, and are in the offshore Rose Canyon-Newport-Inglewood, Coronado Bank, Palos Verdes, and San Diego Trough fault zones. In addition we describe a suite of faults imaged at the base of the continental slope between Dana Point and Del Mar, California. Our new interpretations are based on high-resolution, multichannel seismic (MCS), as well as very high resolution Huntec and GeoPulse seismic-reflection profiles collected by the U.S. Geological Survey from 1998 to 2000 and MCS data collected by WesternGeco in 1975 and 1981, which have recently been made publicly available. Between La Jolla and Newport Beach, California, the Rose Canyon and Newport-Inglewood fault zones are multistranded and generally underlie the shelf break. The Rose Canyon fault zone has a more northerly strike; a left bend in the fault zone is required to connect with the Newport-Inglewood fault zone. A prominent active anticline at mid-slope depths (300-400 m) is imaged seaward of where the Rose Canyon fault zone merges with the Newport-Inglewood fault zone. The Coronado Bank fault zone is a steeply dipping, northwest-trending zone consisting of multiple strands that are imaged from south of the U.S.-Mexico border to offshore of San Mateo Point. South of the La Jolla fan valley, the Coronado Bank fault zone is primarily transtensional; this section of the fault zone ends at the La Jolla fan valley in a series of horsetail splays. The northern section of the Coronado Bank fault zone is less well developed. North of the La Jolla fan valley, the Coronado Bank fault zone forms a positive flower structure that can be mapped at least as far north as Oceanside, a distance of ??35 km. However, north of Oceanside, the Coronado Bank

  11. Coulomb stress changes imparted by simulated M>7 earthquakes to major fault surfaces in Southern California (United States)

    Rollins, J. C.; Ely, G. P.; Jordan, T. H.


    To study static stress interactions between faults in southern California and identify cases where one large earthquake could trigger another, we select fourteen M>7 events simulated by the SCEC/CME CyberShake project and calculate the Coulomb stress changes those events impart to major fault surfaces in the UCERF2 fault model for the region. CyberShake simulates between 6 and 32 slip distributions for each event at a slip sampling resolution of 1 km, and we calculate stress changes on fault surfaces at the same resolution, a level of detail which is unprecedented in studies of stress transfer and which allows us to study the way that variabilities in slip on the source can affect imparted stress changes. We find that earthquakes rupturing the southern San Andreas fault generally decrease Coulomb stress on right-lateral faults in the Los Angeles basin, while M>7 events on the San Jacinto, Elsinore, Newport-Inglewood and Palos Verdes faults generally decrease stress on parallel right-lateral faults but increase Coulomb stress on the Mojave or San Bernardino sections of the San Andreas. Stress interactions between strike-slip and thrust faults and between the San Andreas and Garlock faults depend on the rupture area of the source. Coulomb stress changes imparted by simulated SAF events to locations on the San Jacinto and Garlock faults within ~8 km of the San Andreas appear to be influenced more by the nearby distribution of high and low slip on the San Andreas than by the overall slip distribution across the entire rupture. Using a simplified model, we calculate that an area of no slip surrounded by high slip on a rupture imparts strong Coulomb stress increases ≤7 km to either side of the source fault, possibly explaining the apparent ~8-km range of influence of local slip on the San Andreas. Additionally, we devise a method for evaluating uncertainty values in Coulomb stress changes caused by uncertainties in the strike, dip and rake of the receiver fault. These

  12. Carlsbad, San Onofre, and San Mateo Fault Zones: Possible Right-Lateral Offset Along the Slope-Basin Transition, Offshore Southern California (United States)

    Conrad, J. E.; Dartnell, P.; Sliter, R. W.; Ryan, H. F.; Maier, K. L.; Brothers, D. S.


    Several poorly understood faults are exposed along the mid- and lower slope offshore southern California from Encinitas to San Clemente. From south to north, these faults have been referred to as the Carlsbad, San Onofre, and San Mateo fault zones, which are generally characterized as nearly vertical to steeply east-dipping faults with a reverse slip component. The U.S. Geological Survey collected high-resolution seismic reflection and bathymetric data from 2009-2012 to better characterize these faults. From offshore Encinitas to Oceanside, these data reveal a complex and variable fault zone that structurally controls the slope-basin transition. In this area, the faults show both reverse as well as normal offset, but may also include an unknown amount of strike-slip offset. North of Oceanside, however, faulting shows clear evidence of right-lateral slip, offsetting submarine channels near the base of the slope by approximately 60 m. North of these offset channels, the base of the slope bends about 30° to the west, following the trend of the San Mateo fault zone, but fault strands on strike with those that offset the channels trend obliquely up slope, appearing to merge with the Newport-Inglewood fault zone (NIFZ) on the shelf. These fault strands consist of several en echelon left-stepping segments separated by "pop-up" structures, which imply a significant component of right-lateral offset along this fault zone, and thus may serve to transfer right-lateral slip from faults along the base of the slope to the NIFZ. This fault zone also separates structures associated with the San Mateo fold and thrust belt to the west from undeformed slope sediments to the east. The existence of significant right-lateral slip on faults along the slope and slope-basin transition has implications for assessing seismic hazards associated with the NIFZ, and also provides constraints on possible reverse motion on the hypothesized Oceanside Thrust.

  13. New High-Resolution 3D Imagery of Fault Deformation and Segmentation of the San Onofre and San Mateo Trends in the Inner California Borderlands (United States)

    Holmes, J. J.; Driscoll, N. W.; Kent, G. M.; Bormann, J. M.; Harding, A. J.


    The Inner California Borderlands (ICB) is situated off the coast of southern California and northern Baja. The structural and geomorphic characteristics of the area record a middle Oligocene transition from subduction to microplate capture along the California coast. Marine stratigraphic evidence shows large-scale extension and rotation overprinted by modern strike-slip deformation. Geodetic and geologic observations indicate that approximately 6-8 mm/yr of Pacific-North American relative plate motion is accommodated by offshore strike-slip faulting in the ICB. The farthest inshore fault system, the Newport-Inglewood Rose Canyon (NIRC) fault complex is a dextral strike-slip system that extends primarily offshore approximately 120 km from San Diego to the San Joaquin Hills near Newport Beach, California. Based on trenching and well data, the NIRC fault system Holocene slip rate is 1.5-2.0 mm/yr to the south and 0.5-1.0 mm/yr along its northern extent. An earthquake rupturing the entire length of the system could produce an Mw 7.0 earthquake or larger. West of the main segments of the NIRC fault complex are the San Mateo and San Onofre fault trends along the continental slope. Previous work concluded that these were part of a strike-slip system that eventually merged with the NIRC complex. Others have interpreted these trends as deformation associated with the Oceanside Blind Thrust fault purported to underlie most of the region. In late 2013, we acquired the first high-resolution 3D P-Cable seismic surveys (3.125 m bin resolution) of the San Mateo and San Onofre trends as part of the Southern California Regional Fault Mapping project aboard the R/V New Horizon. Analysis of these volumes provides important new insights and constraints on the fault segmentation and transfer of deformation. Based on the new 3D sparker seismic data, our preferred interpretation for the San Mateo and San Onofre fault trends is they are transpressional features associated with westward

  14. TEM prospection on quaternary faults: the case of San Ramón Fault (SRF), Central Chile (United States)

    Estay, N. P.; Yanez, G. A.; Maringue, J. I.


    Quaternary faults are relevant study objects in geosciences to better estimation of seismic risk. Nowadays main efforts are focused on the improvement of paleoseismology and geophysics techniques. At this regard, we present here a TEM prospection of the San Ramón quaternary fault in the southern Andes. This fault has no record of historic activation, however, given its proximity to the Chilean capital, hazardous estimate is mandatory. Evidences of the SRF are restricted to geomorphologic features, and associated secondary faults on the hanging wall block, but any outcrop of the main fault have been identified. To observe the main fault in the basement rock, cover by a 30-100 m sedimentary basin, we carried out a TEM experiment. The best advantage of the TEM methodology compared to other near-surface electrical methods is it capacity to reach greater penetration depth compared to its spatial sampling rate. Taking this advantage, we define a 25x25 m transmitter loop (Tx) and 5x5 m receiver loop (Rx), allowing the suitable resolution to observe the fault core. To reach a deeper penetration depth but keeping high resolution of the shallow parts, we made two complementary measurements, the first with one-turn transmitter loop, and the second with 4-turn transmitter loops, to resolve the early and late times properly. As result we define vertical profiles of 100-150m depth, and including 48 measures (24 of one-turn transmitter loop, and 24 of four-turn transmitter loop), the resulting pseudo 2D image is a 500m profile with depth extent of 150m. In this section we can observe different resistivity domain, with a horizontal continuity in many measures. The experiment allows to cross the sedimentary cover, and observe the top of the basement rock. In the rock domain, it can be observed a high resistivity body, interpreted as a pristine rock, and some extremely low resistivity bodies, that are interpreted as a fractured rock saturated with water, and eventually mapping a

  15. Post-Miocene Right Separation on the San Gabriel and Vasquez Creek Faults, with Supporting Chronostratigraphy, Western San Gabriel Mountains, California (United States)

    Beyer, Larry A.; McCulloh, Thane H.; Denison, Rodger E.; Morin, Ronald W.; Enrico, Roy J.; Barron, John A.; Fleck, Robert J.


    The right lateral San Gabriel Fault Zone in southern California extends from the northwestern corner of the Ridge Basin southeastward to the eastern end of the San Gabriel Mountains. It bifurcates to the southeast in the northwestern San Gabriel Mountains. The northern and older branch curves eastward in the range interior. The southern younger branch, the Vasquez Creek Fault, curves southeastward to merge with the Sierra Madre Fault Zone, which separates the San Gabriel Mountains from the northern Los Angeles Basin margin. An isolated exposure of partly macrofossiliferous nearshore shallow-marine sandstone, designated the Gold Canyon beds, is part of the southwest wall of the fault zone 5.5 km northwest of the bifurcation. These beds contain multiple subordinate breccia-conglomerate lenses and are overlain unconformably by folded Pliocene-Pleistocene Saugus Formation fanglomerate. The San Gabriel Fault Zone cuts both units. Marine macrofossils from the Gold Canyon beds give an age of 5.2+-0.3 Ma by 87Sr/86Sr analyses. Magnetic polarity stratigraphy dates deposition of the overlying Saugus Formation to between 2.6 Ma and 0.78 Ma. Distinctive metaplutonic rocks of the Mount Lowe intrusive suite in the San Gabriel Range are the source of certain clasts in both the Gold Canyon beds and Saugus Formation. Angular clasts of nondurable Paleocene sandstone also occur in the Gold Canyon beds. The large size and angularity of some of the largest of both clast types in breccia-conglomerate lenses of the beds suggest landslides or debris flows from steep terrain. Sources of Mount Lowe clasts, originally to the north or northeast, are now displaced southeastward by faulting and are located between the San Gabriel and Vasquez Creek faults, indicating as much as 12+-2 km of post-Miocene Vasquez Creek Fault right separation, in accord with some prior estimates. Post-Miocene right slip thus transferred onto the Vasquez Creek Fault southeast of the bifurcation. The right separation

  16. Extensive barite deposits on a seepage site along the offshore San Clemente Fault, Mexican Borderland (United States)

    Gwiazda, R.; Paull, C. K.; Maier, K. L.; McGann, M.; Caress, D. W.; Herguera, J. C.; Lundsten, E. M.; Anderson, K.


    A 6 km-long section of San Clemente Fault Zone was recently mapped with an Autonomous Underwater Vehicle, 53 km south of the U.S.-Mexican border in ~1850 m water depth. The surface expression of the fault zone as well as patches of especially rough seafloor texture on both flanks of the fault are distinctively recognized in 1-m resolution bathymetry. On the SW side of the fault, apparently accreted ovoid mounds 10 to 30 meters in diameter and up to 11 m high cover up to 50% of the seafloor within a restricted 0.43 km2 area. In contrast, on the NE side similar mounds are identified along outcropping bedding planes, suggesting that on the NE side mound formation and distribution is stratigraphically controlled. On a dive with the Remotely Operated Vehicle (ROV) Doc Ricketts we observed variably colored ~1 m-sized material clusters accreted onto the sides and top of the mounds. Some clusters consist of white, fragile, vertical spires, suggesting active upward growth of chemical precipitates. The lightly colored clusters are partially covered with gelatinous and filamentous bacterial mats on their uppermost surfaces. The mounds broke easily when prodded with the ROV arm. X-ray powder diffraction analyses show the mounds are composed of barite. Black varnish variably covers the mounds and may be related to time since the last episode of barite precipitation in a particular area. Except for thickets of tubeworms, mounds are notably devoid of attached fauna. Concentration of methane in sediment pore fluids extracted from push cores collected at the base of a tubeworm thicket was low, in the order of micromolar to undetectable Sulfur isotopic compositions of seven rock samples range between δ34S +20.1‰ to +27.5‰, indicating the sulfate in barite is mainly seawater-derived (δ34S +21) which has undergone a small degree of sulfur reduction. Overall, barite deposits covered 14% of the area within a 500 m wide band along the SW side of the fault, and 22% within a 650 m

  17. Dislocation model for aseismic fault slip in the transverse ranges of Southern California (United States)

    Cheng, A.; Jackson, D. D.; Matsuura, M.


    Geodetic data at a plate boundary can reveal the pattern of subsurface displacements that accompany plate motion. These displacements are modelled as the sum of rigid block motion and the elastic effects of frictional interaction between blocks. The frictional interactions are represented by uniform dislocation on each of several rectangular fault patches. The block velocities and fault parameters are then estimated from geodetic data. Bayesian inversion procedure employs prior estimates based on geological and seismological data. The method is applied to the Transverse Ranges, using prior geological and seismological data and geodetic data from the USGS trilateration networks. Geodetic data imply a displacement rate of about 20 mm/yr across the San Andreas Fault, while the geologic estimates exceed 30 mm/yr. The prior model and the final estimates both imply about 10 mm/yr crustal shortening normal to the trend of the San Andreas Fault. Aseismic fault motion is a major contributor to plate motion. The geodetic data can help to identify faults that are suffering rapid stress accumulation; in the Transverse Ranges those faults are the San Andreas and the Santa Susana.

  18. Behavior of Repeating Earthquake Sequences in Central California and the Implications for Subsurface Fault Creep

    Energy Technology Data Exchange (ETDEWEB)

    Templeton, D C; Nadeau, R; Burgmann, R


    Repeating earthquakes (REs) are sequences of events that have nearly identical waveforms and are interpreted to represent fault asperities driven to failure by loading from aseismic creep on the surrounding fault surface at depth. We investigate the occurrence of these REs along faults in central California to determine which faults exhibit creep and the spatio-temporal distribution of this creep. At the juncture of the San Andreas and southern Calaveras-Paicines faults, both faults as well as a smaller secondary fault, the Quien Sabe fault, are observed to produce REs over the observation period of March 1984-May 2005. REs in this area reflect a heterogeneous creep distribution along the fault plane with significant variations in time. Cumulative slip over the observation period at individual sequence locations is determined to range from 5.5-58.2 cm on the San Andreas fault, 4.8-14.1 cm on the southern Calaveras-Paicines fault, and 4.9-24.8 cm on the Quien Sabe fault. Creep at depth appears to mimic the behaviors seen of creep on the surface in that evidence of steady slip, triggered slip, and episodic slip phenomena are also observed in the RE sequences. For comparison, we investigate the occurrence of REs west of the San Andreas fault within the southern Coast Range. Events within these RE sequences only occurred minutes to weeks apart from each other and then did not repeat again over the observation period, suggesting that REs in this area are not produced by steady aseismic creep of the surrounding fault surface.

  19. Shallow Subsurface Resistivity Profiles Across the San Jose Fault As It Transects the Cal Poly Pomona Campus (United States)

    Chantrapornlert, K. J.; Polet, J.; Colin, H.


    The San Jose fault is a left-lateral strike-slip fault located in the San Gabriel Valley in Southern California. The 1988 (M4.6) and 1990 (M5.2) Upland earthquakes have been attributed to this fault and it has been suggested that it is capable of producing a magnitude M6.0-6.5 earthquake. Sections of the fault are considered to run through the campus of California State Polytechnic University, Pomona as inferred from a 2001 geotechnical engineering report (Geocon, 2001). As it cuts across the campus, the geotechnical engineering report concluded that it has a reverse component of motion. Ascertaining the precise location of the San Jose fault traces on campus is crucial as the university plans its future buildings. Resistivity surveys were conducted across several suggested traces of the fault. The surveys consisted of 24 electrodes in a Wenner electrode configuration with an electrode spacing that varies between 1-5m. An IRIS Instruments Syscal KID switcher unit provided the power source and data recording hardware. The data was processed using IRIS Prosys II software suite before using Geotomo's Res2Dinv software to obtain 2D images of subsurface resistivity for these profiles. A total of 23 surveys were conducted throughout the campus. Surveys were performed before and after rainfall to compensate for the variation of water content and its effect on resistivity. Preliminary results indicate shallow, north-dipping contrasts in resistivity across many of the areas where the fault was previously identified in the Geocon 2001 report. More data will be analyzed to present an enhanced understanding of the San Jose fault in the vicinity of the Cal Poly Pomona campus at AGU.

  20. Possible Connections Between the Coronado Bank Fault Zone and the Newport-Inglewood, Rose Canyon, and Palos Verdes Fault Zones Offshore San Diego County, California. (United States)

    Sliter, R. W.; Ryan, H. F.


    High-resolution multichannel seismic-reflection and deep-tow Huntec data collected by the USGS were interpreted to map the Coronado Bank fault zone (CBFZ) offshore San Diego County, California. The CBFZ is comprised of several major strands (eastern, central, western) that change in both orientation and degree of deformation along strike. Between Coronado Bank and San Diego, the CBFZ trends N25W and occupies a narrow 7 km zone. Immediately north of La Jolla submarine canyon (LJSC), the easternmost strand changes orientation to almost due north and appears to be offset in a right-lateral sense across the canyon axis. The strand merges with a prominent fault that follows the base of the continental slope in about 600 m water depth. The central portion of the CBFZ is mapped as a negative flower structure and deforms seafloor sediment as far north as 15 km north of LJSC. Farther north, this structure is buried by more than 400 m of basin sediment. Along the eastern edge of the Coronado Bank, the western portion of the CBFZ is characterized by high angle normal faults that dip to the east. North of the Coronado Bank, the western segment follows the western edge of a basement high; it cuts through horizontal basin reflectors and in places deforms the seafloor. We mapped an additional splay of the CBFZ that trends N40W; it is only observed north and west of LJSC. Although the predominant trend of the CBFZ is about N40W, along strike deviations from this orientation of some of the strands indicate that these strands connect with other offshore fault zones in the area. Based on the limited data available, the trend of the CBFZ south of Coronado Bank suggests that it might connect with the Rose Canyon fault zone (RCFZ) that has been mapped in San Diego Bay. North of Coronado Bank, the CBFZ is a much broader fault zone (about 25 km wide) composed of diverging fault strands. The westernmost strand may merge with the western strand of the Palos Verdes fault zone (PVFZ) south of

  1. Data from theodolite measurements of creep rates on San Francisco Bay region faults, California: 1979-2001 (United States)

    Galehouse, Jon S.


    My purpose is to make our creep data on San Francisco Bay region active faults available to the scientific research community. My student research assistants and I measured creep (aseismic slip) rates on these faults from 1979 until my retirement from the project in 2001. These data are further described in my final technical report as principal investigator, which summarizes results from 22 September 1979 through 28 February 2001 (Galehouse, 2001). We made over 2,600 creep measurements, about one-third in the ten years prior to the Loma Prieta earthquake (LPEQ) and two-thirds in the 11.4 years following it. The measurements are continuing to be made by members of the Geosciences Department at San Francisco State University (SFSU) under the direction of Karen Grove and John Caskey. A complete analysis of our results obtained on the Hayward fault is presented in Lienkaemper, Galehouse, and Simpson (2001). A formal report based on the entire San Francisco Bay region data set is in preparation. Data sheets for each site along the fault are available for downloading in Excel format to facilitate analysis of the data. They are also available as tab-delimited raw data. The data include all regular measurement sites, SF–1 through SF–34, and the 20 SFSU and U.S. Geological Survey (USGS) afterslip sites on the Hayward fault.

  2. How does the 2010 El Mayor - Cucapah Earthquake Rupture Connect to the Southern California Plate Boundary Fault System (United States)

    Donnellan, A.; Ben-Zion, Y.; Arrowsmith, R.


    The Pacific - North American plate boundary in southern California is marked by several major strike slip faults. The 2010 M7.2 El Mayor - Cucapah earthquake ruptured 120 km of upper crust in Baja California to the US-Mexico border. The earthquake triggered slip along an extensive network of faults in the Salton Trough from the Mexican border to the southern end of the San Andreas fault. Earthquakes >M5 were triggered in the gap between the Laguna Salada and Elsinore faults at Ocotillo and on the Coyote Creek segment of the San Jacinto fault 20 km northwest of Borrego Springs. UAVSAR observations, collected since October of 2009, measure slip associated with the M5.7 Ocotillo aftershock with deformation continuing into 2014. The Elsinore fault has been remarkably quiet, however, with only M5.0 and M5.2 earthquakes occurring on the Coyote Mountains segment of the fault in 1940 and 1968 respectively. In contrast, the Imperial Valley has been quite active historically with numerous moderate events occurring since 1935. Moderate event activity is increasing along the San Jacinto fault zone (SJFZ), especially the trifurcation area, where 6 of 12 historic earthquakes in this 20 km long fault zone have occurred since 2000. However, no recent deformation has been detected using UAVSAR measurements in this area, including the recent M5.2 June 2016 Borrego earthquake. Does the El Mayor - Cucapah rupture connect to and transfer stress primarily to a single southern California fault or several? What is its role relative to the background plate motion? UAVSAR observations indicate that the southward extension of the Elsinore fault has recently experienced the most localized deformation. Seismicity suggests that the San Jacinto fault is more active than neighboring major faults, and geologic evidence suggests that the Southern San Andreas fault has been the major plate boundary fault in southern California. Topographic data with 3-4 cm resolution using structure from motion from

  3. Seismic hazard in low slip rate crustal faults, estimating the characteristic event and the most hazardous zone: study case San Ramón Fault, in southern Andes (United States)

    Estay, Nicolás P.; Yáñez, Gonzalo; Carretier, Sebastien; Lira, Elias; Maringue, José


    Crustal faults located close to cities may induce catastrophic damages. When recurrence times are in the range of 1000-10 000 or higher, actions to mitigate the effects of the associated earthquake are hampered by the lack of a full seismic record, and in many cases, also of geological evidences. In order to characterize the fault behavior and its effects, we propose three different already-developed time-integration methodologies to define the most likely scenarios of rupture, and then to quantify the hazard with an empirical equation of peak ground acceleration (PGA). We consider the following methodologies: (1) stream gradient and (2) sinuosity indexes to estimate fault-related topographic effects, and (3) gravity profiles across the fault to identify the fault scarp in the basement. We chose the San Ramón Fault on which to apply these methodologies. It is a ˜ 30 km N-S trending fault with a low slip rate (0.1-0.5 mm yr-1) and an approximated recurrence of 9000 years. It is located in the foothills of the Andes near the large city of Santiago, the capital of Chile (> 6 000 000 inhabitants). Along the fault trace we define four segments, with a mean length of ˜ 10 km, which probably become active independently. We tested the present-day seismic activity by deploying a local seismological network for 1 year, finding five events that are spatially related to the fault. In addition, fault geometry along the most evident scarp was imaged in terms of its electrical resistivity response by a high resolution TEM (transient electromagnetic) profile. Seismic event distribution and TEM imaging allowed the constraint of the fault dip angle (˜ 65°) and its capacity to break into the surface. Using the empirical equation of Chiou and Youngs (2014) for crustal faults and considering the characteristic seismic event (thrust high-angle fault, ˜ 10 km, Mw = 6.2-6.7), we estimate the acceleration distribution in Santiago and the hazardous zones. City domains that are under

  4. Offset of latest pleistocene shoreface reveals slip rate on the Hosgri strike-slip fault, offshore central California (United States)

    Johnson, Samuel Y.; Hartwell, Stephen R.; Dartnell, Peter


    The Hosgri fault is the southern part of the regional Hosgri–San Gregorio dextral strike‐slip fault system, which extends primarily in the offshore for about 400 km in central California. Between Morro Bay and San Simeon, high‐resolution multibeam bathymetry reveals that the eastern strand of the Hosgri fault is crossed by an ∼265  m wide slope interpreted as the shoreface of a latest Pleistocene sand spit. This sand spit crossed an embayment and connected a western fault‐bounded bedrock peninsula and an eastern bedrock highland, a paleogeography resembling modern coastal geomorphology along the San Andreas fault. Detailed analysis of the relict shoreface with slope profiles and slope maps indicates a lateral slip rate of 2.6±0.9  mm/yr, considered a minimum rate for the Hosgri given the presence of an active western strand. This slip rate indicates that the Hosgri system takes up the largest share of the strike‐slip fault budget and is the most active strike‐slip fault west of the San Andreas fault in central California. This result further demonstrates the value and potential of high‐resolution bathymetry in characterization of active offshore faults.

  5. Seismicity around Parkfield correlates with static shear stress changes following the 2003 Mw6.5 San Simeon earthquake (United States)

    Meng, Xiaoteng; Peng, Zhigang; Hardebeck, Jeanne L.


    Earthquakes trigger other earthquakes, but the physical mechanism of the triggering is currently debated. Most studies of earthquake triggering rely on earthquakes listed in catalogs, which are known to be incomplete around the origin times of large earthquakes and therefore missing potentially triggered events. Here we apply a waveform matched-filter technique to systematically detect earthquakes along the Parkfield section of the San Andreas Fault from 46 days before to 31 days after the nearby 2003 Mw6.5 San Simeon earthquake. After removing all possible false detections, we identify ~8 times more earthquakes than in the Northern California Seismic Network catalog. The newly identified events along the creeping section of the San Andreas Fault show a statistically significant decrease following the San Simeon main shock, which correlates well with the negative static stress changes (i.e., stress shadow) cast by the main shock. In comparison, the seismicity rate around Parkfield increased moderately where the static stress changes are positive. The seismicity rate changes correlate well with the static shear stress changes induced by the San Simeon main shock, suggesting a low friction in the seismogenic zone along the Parkfield section of the San Andreas Fault.

  6. Paleoseismic Investigations of the Walnut Site on the San Jacinto Fault (United States)

    Fumal, T.E.; Kendrick, K.J.


    The Walnut paleoseismic site is located along the northern San Jacinto fault about 3 km southeast of the San Bernardino, California city center (Figures 1, 2). More than 340 meters of trenches were excavated across the fault zone at this site as part of an Alquist-Priolo fault study (Figure 3). We photographed and logged the SE wall and most of the NE wall of trench 1, both walls of trenches 2 and 7, the NW walls of trenches 3 and 4 and the SE wall of trench 6. After carefully cleaning the trench walls we put up a 1m by 0.5m string and nail grid. For trenches 1, 2, 6, and 7, we photographed each 1m by 0.5m panel individually and photologged on these unrectified photos. These large-scale photos were later rectified to remove the distortion due to irregularities in the trench walls and slight distortion introduced by the camera lens. Field linework was then transferred to the rectified photomosaics. We also took a set of overview photographs for each trench taken from the top of the trench towards the opposite wall. We spliced together these overview photos to make photomosaics of all of the trenches. Because the photos were taken at a downward angle, there is significant distortion. Some of this distortion has been corrected: an attempt was made to keep horizontal grid lines horizontal and there has been some horizontal scaling to align vertical lines between benches. Although the string and nail grid spacing is 1 meter by 0.5 meter, because of the distortion in the photos and subsequent adjustments, the scale is variable along the benches, from bench to bench and from trench to trench for these overview mosaics. This report serves principally as a repository for the overview photomosaics. Sheet 1 shows the overview mosaics for both walls of trenches 1 and 2 along with some linework including most of the fault traces, a prominent unconformity within the fluvial deposits and the larger bodies of liquefied sand. Sheet 2 shows the overview mosaics for the SE wall of

  7. Faults (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Through the study of faults and their effects, much can be learned about the size and recurrence intervals of earthquakes. Faults also teach us about crustal...

  8. Mapping Fault Slip in Central California Using Satellite, Airborne InSAR and GPS (United States)

    Liu, Zhen; Lundgren, Paul; Hensley, Scott


    The central San Andreas fault is accommodating relative motion between the Sierra Nevada-Great Valley block and the Pacific plate in central California. It is creeping along the ~60 km long central segment while changing to locking towards the northwest and southeast. Characterizing its creeping nature and on and off-fault deformation are crucial for improved earthquake hazard assessment in the region. We use L-band ALOS PALSAR, NASA airborne UAVSAR data and geodetic measurements to map the fault slip variation. Our results show a distinct change in shallow fault creep and fault slip at depth from the central creeping to the transitional segment. Our work demonstrates that airborne UAVSAR provides useful constraints on shallow creep and near fault deformation. Continuing observations would be essential in capturing time-varying faulting behaviours and their implication towards present and future earthquake activities.

  9. Data from Theodolite Measurements of Creep Rates on San Francisco Bay Region Faults, California (United States)

    U.S. Geological Survey, Department of the Interior — The data comprise an archive of repeated surveyed measurements to monitor surface fault creep (a form of gradual tectonic movement) occurring along active faults in...

  10. Three-dimensional fault framework of the 2014 South Napa Earthquake, San Francisco Bay region, California (United States)

    Graymer, R. W.


    Assignment of the South Napa earthquake to a mapped fault is difficult, as it occurred where three large, northwest-trending faults converge and may interact in the subsurface. The surface rupture did not fall on the main trace of any of these faults, but instead between the Carneros and West Napa faults and northwest along strike from the northern mapped end of the Franklin Fault. The 2014 rupture plane appears to be nearly vertical, based on focal mechanisms of the mainshock and connection of the surface trace/rupture to the relocated hypocenter (J. Hardebeck, USGS). 3D surfaces constructed from published data show that the Carneros Fault is a steeply west-dipping fault that runs just west of the near-vertical 2014 rupture plane. The Carneros Fault does not appear to have been involved in the earthquake, although relocated aftershocks suggest possible minor triggered slip. The main West Napa Fault is also steeply west-dipping and that its projection intersects the 2014 rupture plane at around the depth of the mainshock hypocenter. UAVSAR data (A. Donnellan, JPL) and relocated aftershocks suggest that the main West Napa Fault experienced triggered slip/afterslip along a length of roughly 20 km. It is possible that the 2014 rupture took place along a largely unrecognized westerly strand of the West Napa Fault. The Franklin Fault is a steeply east-dipping fault (with a steeply west-dipping subordinate trace east of Mare Island) that has documented late Quaternary offset. Given the generally aligned orientation of the 3D fault surfaces, an alternative interpretation is that the South Napa earthquake occurred on the northernmost reach of the Franklin Fault within it's 3D junction with the West Napa Fault. This interpretation is supported, but not proven, by a short but prominent linear feature in the UAVSAR data at Slaughterhouse Point west of Vallejo, along trend south-southeast of the observed coseismic surface rupture.

  11. Spatio-temporal mapping of plate boundary faults in California using geodetic imaging (United States)

    Donnellan, Andrea; Arrowsmith, Ramon; DeLong, Stephen B.


    The Pacific–North American plate boundary in California is composed of a 400-km-wide network of faults and zones of distributed deformation. Earthquakes, even large ones, can occur along individual or combinations of faults within the larger plate boundary system. While research often focuses on the primary and secondary faults, holistic study of the plate boundary is required to answer several fundamental questions. How do plate boundary motions partition across California faults? How do faults within the plate boundary interact during earthquakes? What fraction of strain accumulation is relieved aseismically and does this provide limits on fault rupture propagation? Geodetic imaging, broadly defined as measurement of crustal deformation and topography of the Earth’s surface, enables assessment of topographic characteristics and the spatio-temporal behavior of the Earth’s crust. We focus here on crustal deformation observed with continuous Global Positioning System (GPS) data and Interferometric Synthetic Aperture Radar (InSAR) from NASA’s airborne UAVSAR platform, and on high-resolution topography acquired from lidar and Structure from Motion (SfM) methods. Combined, these measurements are used to identify active structures, past ruptures, transient motions, and distribution of deformation. The observations inform estimates of the mechanical and geometric properties of faults. We discuss five areas in California as examples of different fault behavior, fault maturity and times within the earthquake cycle: the M6.0 2014 South Napa earthquake rupture, the San Jacinto fault, the creeping and locked Carrizo sections of the San Andreas fault, the Landers rupture in the Eastern California Shear Zone, and the convergence of the Eastern California Shear Zone and San Andreas fault in southern California. These examples indicate that distribution of crustal deformation can be measured using interferometric synthetic aperture radar (InSAR), Global Navigation

  12. Field imaging spectroscopy and inferring a blind thrust earthquake history from secondary faulting: 1944 San Juan Earthquake, Argentina (United States)

    Ragona, Daniel Eduardo

    The studies presented in this dissertation provide new approaches to extract paleo-earthquake information from the geological record. The first chapter describes the development of Field Imaging Spectroscopy, a new methodology for data acquisition and analysis in paleoseismology. The study shows the steps followed from data acquisition, pre-processing, processing and analysis of high spatial and spectral resolution images obtained from cores and a large sample from a fault zone collected at Hog Lake, San Jacinto Fault, Southern California. The study demonstrate that hyperspectral data can be obtained in the field using portable scanners and that high spatial and spectral resolution in the visible to short wave infrared provide a way to enhance subtle or invisible stratigraphic and structural features. The second chapter focuses on the use of neural networks and naive Bayesian classifiers to automatically classify hyperspectral image data, providing an objective mapping of the structure of cores, samples and field exposures. The results of this study show that a system integrated by a hyperspectral scanner and pattern recognition algorithms can work as an enhanced eye and an objective classifier to provide the geologist with additional information that facilitates the final description, interpretation and correlation of the geology in paleoseismic exposures and cores. The hyperspectral dataset collected together with a spectral library of the materials observed in the excavation provide a new way to archive paleoseismological data for future analysis. Finally, in chapter 3, an innovative approach to study blind thrust faults is presented. The study of the secondary La Laja fault near San Juan, Argentina shows that the earthquake history recorded in a minor fault provides an indirect way to study the occurrence of large M˜7 earthquakes at depth. This investigation also provides the first and perhaps the longest record of the earthquake activity of a blind thrust

  13. Internal structure of the San Jacinto fault zone at Jackass Flat from data recorded by a dense linear array (United States)

    Qiu, H.; Ben-Zion, Y.; Ross, Z. E.; Share, P.-E.; Vernon, F. L.


    The internal structure of the Clark fault in the trifurcation area of the San Jacinto fault zone is imaged using seismograms recorded by a dense linear array (Jackass Flat, JF) crossing the surface trace of the fault and an adjacent array (TR) to the SW. Delay times between phase arrivals associated with ∼3500 local earthquakes and nine teleseismic events are used to estimate velocity variations within the arrays. The teleseismic P waves travel faster beneath the TR than the JF array, in contrast to larger scale tomographic results. Statistical analysis of local P-wave delay times indicates that the entire JF array, with an aperture of ∼400 m, is inside a low-velocity damage zone. This low-velocity zone is bounded on the NE side by a shallow bimaterial interface generating fault zone head waves, and it contains an inner zone of more intense damage generating fault zone trapped waves. The P-wave velocity contrast across the local bounding bimaterial interface is 10-15 per cent. The trapping structure is associated with a width of ∼200 m, S-wave velocity reduction of ∼35 per cent with respect to the surrounding rock, Q-value of ∼20 and depth of ∼3.5 km. The imaging results suggest that the main seismogenic fault is near the SW end of the JF array, in agreement with a prominent geomorphologic feature. The existence of intense local damage on the crustal block with faster larger scale velocity at depth is consistent with common propagation of earthquake ruptures in the area to the NW.

  14. Extremely weak fault planes: An estimate of focal mechanisms from stationary seismic activity in the San'in district, Japan (United States)

    Iio, Yoshihisa; Kishimoto, Shinji; Nakao, Setsuro; Miura, Tsutomu; Yoneda, Itaru; Sawada, Masayo; Katao, Hiroshi


    In this paper, using data from dense seismic observations in and around the seismic belt of the San'in district, Japan, we describe our analysis of focal mechanisms of stationary seismic activity, estimated stress states, and pore fluid pressures. We found these focal mechanisms to be described by the estimated stress field, suggesting that the stress field can be treated as uniform in each sub-region of the study area. We also found that events occurred even on unfavorably oriented fault planes with small shear stress. Further, we inferred that pore fluid pressures of approximately 20% of the faults analyzed are greater than the magnitude of minimum principal stress, when we assume μ = 0.6. A possible explanation is localized high pore fluid pressure anomalies; another is the coefficient of friction of at least a part of faults analyzed in the study area being substantially smaller than 0.6, which we view as more plausible, since it is difficult to maintain pore fluid pressures higher than the magnitude of minimum principal stress for long periods of time.

  15. Fault Trends and the Evolution of the Pacific-North America Transform in Southern California (United States)

    Legg, M. R.; Kamerling, M. J.


    The Pacific-North America (PAC-NOAM) transform boundary evolved during the past 30 Ma, lengthening more than 1000 km and spanning a zone exceeding 200-km across southern California. The relative plate motion vector has been estimated using seafloor magnetic anomaly patterns. Orientations of major transform fault segments within this boundary provide direct evidence of the relative motion at the time these faults formed, where the faults preserve their original orientations. Avoiding areas of known vertical-axis block rotations, we find at least three major fault trends that document past and present tectonic kinematics. A northwest trend of 330 degrees is related to subduction trends in the forearc region that defined the late Mesozoic and early Tertiary coastline and has subsequently controlled the orientation of oblique rifting during the Neogene initiation and growth of the PAC-NOAM transform. This trend is manifest in the San Diego Trough and adjacent coastal rifts and associated fault zones including the Coronado Bank and Newport-Inglewood. The middle Miocene transform orientation appears to be 300-310 degrees, which imparted extensional character to faults reactivated with older subduction trends. Major faults inferred to represent Neogene transform fault segments with this trend include the Whittier, Palos Verdes Hills, Santa Cruz-Catalina Ridge, Catalina Escarpment, and possibly the Mojave segment of the San Andreas fault. In late Miocene time, the plate motion vector rotated clockwise eventually achieving its modern orientation of about 320 degrees. Active faulting showing pure strike-slip character on the San Clemente - San Isidro fault zone and the Imperial Fault show this trend, as do transform faults in the northern Gulf of California. An intermediate trend is apparent in some areas along the San Clemente fault zone in the Borderland, and along the Elsinore and San Jacinto fault zones, which transect the Peninsular Ranges. The intermediate trends may

  16. Teatrikunstnik Andrea Haamer: Olen alati unistanud Eestisse tagasi tulla / Andrea Haamer ; intervjueerinud Andreas Sepp, Anneli Sihvart

    Index Scriptorium Estoniae

    Haamer, Andrea


    Eesti juurtega lava- ja kostüümikunstnikust Andrea T. Haamerist, kes on Eestis kujundanud kolm balletti. 25. veebruaril avatavast neljandast Jõhvi balletifestivalist, kus avatakse Andrea Haameri näitus

  17. Determination of Aquifer and Fault Permeabilities by Studying the Poroelastic Response of Rocks Using InSAR in the Upper Coachella Valley Area, CA, USA (United States)

    Appana, R.; Saar, M. O.


    Coachella Valley in California is an area enclosed between Little Bernardino, San Jacinto, and San Bernardino Mountains. The San Andreas Fault system runs through the valley. Satellite interferometry (InSAR) has revealed a differential uplift of the land surface over a period of time across two basin-cutting faults, the Banning Fault (BF) and the Garnet Hill Fault (GHF), in the upper Coachella valley region. This uplift is due to a combined effect of both elastic response of the aquifer due to groundwater recharge at the White Water Spreading Facility and tectonic stresses in the region (Wisely et. al., AGU 2006). In this region, faults appear to act as semi-permeable barriers to groundwater flow (Wisely et. al., AGU 2005). As a result, water levels are not restored uniformly throughout the entire aquifer leading to differential uplift of the land surface. Hence, by developing a numerical model of groundwater flow in this aquifer system, that includes hydraulic representations of the existing faults, a better water management strategy can be achieved which aims at restoring the groundwater levels throughout the aquifer. In addition, the proposed model would better constrain fault permeabilities with implications for research related to earthquake dynamics and assessment of potential slip along segments of the San Andreas Fault system. A finite element code is being used to implement the groundwater flow model. The model simulates the poroelastic response of the faulted aquifer to changing groundwater levels. InSAR data and well data collected in this region will be used to constrain the model yielding parameters such as the hydraulic conductivity field of the aquifer and fault system, storage co-efficients, skeletal compressibilities, and the grounwater influx, and outflux, of the basin.

  18. [Andreas Vesalius in Pisa]. (United States)

    Ciranni, Rosalba


    Andreas Vesalius is the most commanding figure in European medicine, after Galen and before Harvey. His dissections and lectures were in considerable demand. Having just published the De humani corporis fabrica, and before operating as a private physician of Emperor Charles V, the anatomist spent some months conducting demonstrations of anatomy at the universities of Bologna, Pisa and Florence. The present study aim to reconstruct the journey he made to Pisa, where he was invited by Duke Cosimo I De' Medici. The work of Andrea Corsini and O'Malley, the study of Vesalius' Epistola... rationem modumque propinandi radicis Chynae dedocti... , and other documents make possible a more detailed reconstruction of the period Vesalius spent in the Nuovo Studio Pisano, carrying out public human dissections, discussing and refuting most of the Galenic doctrine.

  19. The Andrea Levialdi Fellowship (United States)

    Fieschi, Roberto

    My first encounter with Cuba dates back to winter 1967-1968 at the Cultural Congress of La Havana, a very large international event to promote greater understanding of the reality of the Cuban Revolution. In fact the person invited was my friend and colleague Andrea Levialdi (Andrea already knew Cuba and loved it) who, unable to participate, allowed me to go in her place. So I landed at the airport of the "first free country in Latin America" with the delegation of the Italian Communist Party. In Havana I met other Italian physicists whom I already knew, among them Bruno Vitale and Daniele Amati. They, like me, were embarrassed by the generous hospitality of `Havana Libre,' especially in a country which was going through such difficulties. Despite our best efforts we did not succeed in receiving a more modest welcome.

  20. Detection of small earthquakes with dense array data: example from the San Jacinto fault zone, southern California (United States)

    Meng, Haoran; Ben-Zion, Yehuda


    We present a technique to detect small earthquakes not included in standard catalogues using data from a dense seismic array. The technique is illustrated with continuous waveforms recorded in a test day by 1108 vertical geophones in a tight array on the San Jacinto fault zone. Waveforms are first stacked without time-shift in nine non-overlapping subarrays to increase the signal-to-noise ratio. The nine envelope functions of the stacked records are then multiplied with each other to suppress signals associated with sources affecting only some of the nine subarrays. Running a short-term moving average/long-term moving average (STA/LTA) detection algorithm on the product leads to 723 triggers in the test day. Using a local P-wave velocity model derived for the surface layer from Betsy gunshot data, 5 s long waveforms of all sensors around each STA/LTA trigger are beamformed for various incident directions. Of the 723 triggers, 220 are found to have localized energy sources and 103 of these are confirmed as earthquakes by verifying their observation at 4 or more stations of the regional seismic network. This demonstrates the general validity of the method and allows processing further the validated events using standard techniques. The number of validated events in the test day is >5 times larger than that in the standard catalogue. Using these events as templates can lead to additional detections of many more earthquakes.

  1. The Quaternary Silver Creek Fault Beneath the Santa Clara Valley, California (United States)

    Wentworth, Carl M.; Williams, Robert A.; Jachens, Robert C.; Graymer, Russell W.; Stephenson, William J.


    The northwest-trending Silver Creek Fault is a 40-km-long strike-slip fault in the eastern Santa Clara Valley, California, that has exhibited different behaviors within a changing San Andreas Fault system over the past 10-15 Ma. Quaternary alluvium several hundred meters thick that buries the northern half of the Silver Creek Fault, and that has been sampled by drilling and imaged in a detailed seismic reflection profile, provides a record of the Quaternary history of the fault. We assemble evidence from areal geology, stratigraphy, paleomagnetics, ground-water hydrology, potential-field geophysics, and reflection and earthquake seismology to determine the long history of the fault in order to evaluate its current behavior. The fault formed in the Miocene more than 100 km to the southeast, as the southwestern fault in a 5-km-wide right step to the Hayward Fault, within which the 40-km-long Evergreen pull-apart basin formed. Later, this basin was obliquely cut by the newly recognized Mt. Misery Fault to form a more direct connection to the Hayward Fault, although continued growth of the basin was sufficient to accommodate at least some late Pliocene alluvium. Large offset along the San Andreas-Calaveras-Mt Misery-Hayward Faults carried the basin northwestward almost to its present position when, about 2 Ma, the fault system was reorganized. This led to near abandonment of the faults bounding the pull-apart basin in favor of right slip extending the Calaveras Fault farther north before stepping west to the Hayward Fault, as it does today. Despite these changes, the Silver Creek Fault experienced a further 200 m of dip slip in the early Quaternary, from which we infer an associated 1.6 km or so of right slip, based on the ratio of the 40-km length of the strike-slip fault to a 5-km depth of the Evergreen Basin. This dip slip ends at a mid-Quaternary unconformity, above which the upper 300 m of alluvial cover exhibits a structural sag at the fault that we interpret as

  2. [Andreas Vesalius--the life]. (United States)

    De Caro, Raffaele; Goddeeris, Theodoor; Plessas, Pavlos; Biebrouck, Maurits; Steeno, Omer


    The details of Vesalius' life can be found in Charles O'Malley, Andreas Vesalius of Brussels, 1514-1564, (University of California Press, 1964) and in Stephen N Joffe, Andreas Vesalius: The Making, The Madman, and the Myth, (Persona Publishing, 2009). This session reviews the circumstances of his last voyage and his death and other aspects of his life.

  3. Structural characteristics of the Yilan-Yitong and Dunhua-Mishan faults as northern extensions of the Tancheng-Lujiang Fault Zone: New deep seismic reflection results (United States)

    Xu, Ming; Li, Yalin; Hou, Hesheng; Wang, Chengshan; Gao, Rui; Wang, Haiyan; Han, Zhongpeng; Zhou, Aorigele


    The Tancheng-Lujiang Fault Zone (TLFZ) can be subdivided into three segments that exhibit sharp contrasts in their deep structures. A deep seismic reflection profile (length 600 km) across the north part of the TLFZ, which provides new constraints on the structural styles of the northern TLFZ, was recently completed by the Chinese Sinoprobe Project. Here, the TLFZ branches into the Yilan-Yitong Fault (YYF) to the west and the Dunhua-Mishan Fault (DMF) to the east. The YYF developed as an internal fault in the Songnen-Zhangguangcai massif, while the DMF serves as the tectonic boundary between the Nadanhada terrane and the Khanka massif. Both faults developed large-scale flower structures, with that of the YYF being negative and that of the DMF being positive with reverse faults. The Moho in the profile is at a depth of 25-39 km and is offset by the faults. The north part of the TLFZ extends into the upper mantle as thin shear zones with the reflectors truncated in the middle/lower crust. This feature differs from most crustal-scale strike-slip faults that distribute over a discrete shear zone in the lower crust, such as the San Andreas Fault.

  4. Slip on faults in the Imperial Valley Triggered by the 4 April 2010 Mw 7.2 El Major earthquake as revealed by InSAR (United States)

    Wei, M.; Sandwell, D. T.; Fialko, Y.; Bilham, R. G.


    Radar interferometry (InSAR) reveals surface slip on multiple faults in the Imperial Valley triggered by the 2010 Baja M7.2 earthquake. Co-seismic offsets occurred on the San Andreas, Superstition Hills, Imperial, Elmore Ranch, Wienert, Coyote Creek, Elsinore, Yuha Wells, and several minor faults near the town of Ocotillo at the northern end of the mainshock rupture. We documented right-lateral slip (Hills (≤ 50 mm) and Durmid Hill (≤ 10 mm) respectively, and 23 km of the Superstition Hills Fault (≤ 37 mm). Field measurements of slip on the Superstition Hills Fault agree with InSAR and creepmeter measurements to within a few millimeters. Dislocation models of the InSAR data on the Superstition Hills Fault confirm that creep in this sequence, as in previous slip events, is confined to shallow depths (Black solid lines are major faults. Yellow solid lines are faults with observed offsets. Dashed black lines are National and State borders. White star is the epicenter of the 2010 April 4th El Major earthquake. Red dots are aftershocks within one month after the main rupture with magnitude greater than 5, blue 4-5, and green 3-4. Earthquake data are from the Southern California Earthquake Center. Fault names are abbreviated as follows: ERF, Elmore Ranch fault; SHF, Superstition Hills fault; SMF, Superstition Mountains fault; WF, Wienert fault; YWF, Yuha Wells Fault.


    Pampeyan, Earl H.


    Following the earthquake of April 18, 1906, it was discovered that a brick forebay and other parts of the reservoir outlet system were in the slip zone of the San Andreas fault. The original outlet through which water was directed to San Francisco consisted of two tunnels joined at the brick forebay; one tunnel extends 2,820 ft to the east under Bald Hill on Buri Buri Ridge, and the other tunnel intersects the lake bottom about 250 ft west of the forebay. In 1897 a second intake was added to the system, also joining the original forebay. During the present study the accessible parts of this original outlet system were examined with the hope of learning how the system had been affected by fault slip in 1906.

  6. Perspective View, Garlock Fault (United States)


    California's Garlock Fault, marking the northwestern boundary of the Mojave Desert, lies at the foot of the mountains, running from the lower right to the top center of this image, which was created with data from NASA's shuttle Radar Topography Mission (SRTM), flown in February 2000. The data will be used by geologists studying fault dynamics and landforms resulting from active tectonics. These mountains are the southern end of the Sierra Nevada and the prominent canyon emerging at the lower right is Lone Tree canyon. In the distance, the San Gabriel Mountains cut across from the leftside of the image. At their base lies the San Andreas Fault which meets the Garlock Fault near the left edge at Tejon Pass. The dark linear feature running from lower right to upper left is State Highway 14 leading from the town of Mojave in the distance to Inyokern and the Owens Valley in the north. The lighter parallel lines are dirt roads related to power lines and the Los Angeles Aqueduct which run along the base of the mountains.This type of display adds the important dimension of elevation to the study of land use and environmental processes as observed in satellite images. The perspective view was created by draping a Landsat satellite image over an SRTM elevation model. Topography is exaggerated 1.5 times vertically. The Landsat image was provided by the United States Geological Survey's Earth Resources Observations Systems (EROS) Data Center, Sioux Falls, South Dakota.Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11,2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed

  7. Faulting, volcanism, and basin development along the western margin of the southern San Luis Basin segment of the Rio Grande rift, New Mexico and Colorado (United States)

    Turner, K. J.; Thompson, R. A.; Cosca, M. A.; Drenth, B.; Lee, J.; Budahn, J. R.


    The San Luis Basin segment of the northern Rio Grande rift, straddling the Colorado-New Mexico border, is an asymmetrical graben where the major basin-bounding fault is on the east side. In contrast, the west side is a basin-directed dip slope surface cut by north to northwest trending faults with predominantly down-to-southwest displacement. Around 26 Ma, initial rift-related faulting formed broad, shallow basins coincident with basaltic volcanism of the Hinsdale Formation. Later episodes of rifting produced deep and narrow sub-basins generally along the eastern boundary. Basin-fill deposits along the western margin are generally thin. However, in the northern Tusas Mountains, gravity data identifies a small, yet deep, sub-basin that may contain 750 m of basin-filling Los Pinos Formation based on thickness projections derived from mapping. The Los Pinos Formation is overlain by early rift-related Hinsdale Formation basalt flows indicating this sub-basin formed as part of early rifting; the sub-basin may be a southern extension of the Monte Vista graben to the north. The stratigraphic section along the western boundary includes Precambrian basement up to volcanic rocks of the Taos Plateau volcanic field (~5-2Ma). Dips on the early-rift Miocene to Oligocene Hinsdale Formation lavas (3-5 degrees) reflect the cumulative eastward tilting corresponding to continued basin subsidence. Shallower dips (1-2 degrees) on early Pliocene volcanic rocks suggest continued subsidence up to about 3 Ma, or younger. Down-to-southwest faults accommodating eastward tilting are mostly in areas west of Pliocene volcanic rocks; individual faults offset Hinsdale Formation and older rocks by up to 200 m. The few observed faults in the Pliocene volcanic rocks have minor offset. Numerous volcanic vents are in close proximity to the faults along the western boundary. Volcanoes are commonly low to medium relief shield volcanoes with basaltic andesite composition capped by late stage cinder cones

  8. Andreas Vesalius' corpses. (United States)

    Biesbrouck, Maurits; Steeno, Omer


    Judging from his writings, Andreas Vesalius must have had dozens of bodies at his disposal, thirteen of which were definitely from before 1543. They came from cemeteries, places of execution or hospitals. Not only did his students help him obtain the bodies, but also public and judicial authorities. At first, he used the corpses for his own learning purposes, and later to teach his students and to write De humani corporis fabrica, his principal work. Clearly he had an eye for comparative anatomy. He observed anatomical variants and studied foetal anatomy. Occasionally, he would dissect a body to study physiological processes, while the post-mortems on the bodies brought in by the families of the deceased gave him an insight into human pathology. Some of his dissection reports have been preserved.

  9. Strain partitioning and stress perturbation around stepovers and bends of strike-slip faults: Numerical results (United States)

    Wang, Hui; Liu, Mian; Ye, Jiyang; Cao, Jianling; Jing, Yan


    Stepovers and bends along strike-slip faults are where push-up ranges and pull-apart basins are formed. They are also commonly where fault ruptures terminate. Field study and analogue models suggest that the configuration of faults plays a key role in crustal deformation around bends and stepovers, but the related mechanics of stress perturbation, strain partitioning, and fault evolution remains poorly understood. Here we present results of systematical mechanical models of stress changes and strain partitioning around simple stepovers and bends, using three-dimensional viscoelasto-plastic finite element code. Our model predicts elevated deviatoric stress around all stepovers and bends, with higher stresses around the restraining ones. Narrow stepovers localize strain between the fault gaps to form connecting faults, whereas wide stepovers localize strain on the tips of fault segments so the stepovers may evolve into subparallel faults. We explored how various configurations of stepovers and bends change the stress field and strain distribution, and show that these results can help explain some key differences between the pull-apart basins in the Dead Sea Trough and Death Valley, and the push-up ranges along the San Andreas Fault.

  10. California State Waters Map Series: offshore of San Gregorio, California (United States)

    Cochrane, Guy R.; Dartnell, Peter; Greene, H. Gary; Watt, Janet T.; Golden, Nadine E.; Endris, Charles A.; Phillips, Eleyne L.; Hartwell, Stephen R.; Johnson, Samuel Y.; Kvitek, Rikk G.; Erdey, Mercedes D.; Bretz, Carrie K.; Manson, Michael W.; Sliter, Ray W.; Ross, Stephanie L.; Dieter, Bryan E.; Chin, John L.; Cochran, Susan A.; Cochrane, Guy R.; Cochran, Susan A.


    In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within the 3-nautical-mile limit of California's State Waters. The CSMP approach is to create highly detailed seafloor maps through collection, integration, interpretation, and visualization of swath sonar data, acoustic backscatter, seafloor video, seafloor photography, high-resolution seismic-reflection profiles, and bottom-sediment sampling data. The map products display seafloor morphology and character, identify potential marine benthic habitats, and illustrate both the surficial seafloor geology and shallow (to about 100 m) subsurface geology. The Offshore of San Gregorio map area is located in northern California, on the Pacific coast of the San Francisco Peninsula about 50 kilometers south of the Golden Gate. The map area lies offshore of the Santa Cruz Mountains, part of the northwest-trending Coast Ranges that run roughly parallel to the San Andreas Fault Zone. The Santa Cruz Mountains lie between the San Andreas Fault Zone and the San Gregorio Fault system. The nearest significant onshore cultural centers in the map area are San Gregorio and Pescadero, both unincorporated communities with populations well under 1,000. Both communities are situated inland of state beaches that share their names. No harbor facilities are within the Offshore of San Gregorio map area. The hilly coastal area is virtually undeveloped grazing land for sheep and cattle. The coastal geomorphology is controlled by late Pleistocene and Holocene slip in the San Gregorio Fault system. A westward bend in the San Andreas Fault Zone, southeast of the map area, coupled with right-lateral movement along the San Gregorio Fault system have caused regional folding and uplift. The coastal area consists of high coastal bluffs and vertical sea cliffs. Coastal promontories in

  11. The Point Sal–Point Piedras Blancas correlation and the problem of slip on the San Gregorio–Hosgri fault, central California Coast Ranges (United States)

    Colgan, Joseph P.; Stanley, Richard G.


    Existing models for large-magnitude, right-lateral slip on the San Gregorio–Hosgri fault system imply much more deformation of the onshore block in the Santa Maria basin than is supported by geologic data. This problem is resolved by a model in which dextral slip on this fault system increases gradually from 0–10 km near Point Arguello to ∼150 km at Cape San Martin, but such a model requires abandoning the cross-fault tie between Point Sal and Point Piedras Blancas, which requires 90–100 km of right-lateral slip on the southern Hosgri fault. We collected stratigraphic and detrital zircon data from Miocene clastic rocks overlying Jurassic basement at both localities to determine if either section contained unique characteristics that could establish how far apart they were in the early Miocene. Our data indicate that these basins formed in the early Miocene during a period of widespread transtensional basin formation in the central Coast Ranges, and they filled with sediment derived from nearby pre-Cenozoic basement rocks. Although detrital zircon data do not indicate a unique source component in either section, they establish the maximum depositional age of the previously undated Point Piedras Blancas section to be 18 Ma. We also show that detrital zircon trace-element data can be used to discriminate between zircons of oceanic crust and arc affinity of the same age, a potentially useful tool in future studies of the California Coast Ranges. Overall, we find no characteristics in the stratigraphy and provenance of the Point Sal and Point Piedras Blancas sections that are sufficiently unique to prove whether they were far apart or close together in the early Miocene, making them of questionable utility as piercing points.

  12. Complex Paleotopography and Faulting near the Elsinore Fault, Coyote Mountains, southern California (United States)

    Brenneman, M. J.; Bykerk-Kauffman, A.


    The Coyote Mountains of southern California are bounded on the southwest by the Elsinore Fault, an active dextral fault within the San Andreas Fault zone. According to Axen and Fletcher (1998) and Dorsey and others (2011), rocks exposed in these mountains comprise a portion of the hanging wall of the east-vergent Salton Detachment Fault, which was active from the late Miocene-early Pliocene to Ca. 1.1-1.3 Ma. Detachment faulting was accompanied by subsidence, resulting in deposition of a thick sequence of marine and nonmarine sedimentary rocks. Regional detachment faulting and subsidence ceased with the inception of the Elsinore Fault, which has induced uplift of the Coyote Mountains. Detailed geologic mapping in the central Coyote Mountains supports the above interpretation and adds some intriguing details. New discoveries include a buttress unconformity at the base of the Miocene/Pliocene section that locally cuts across strata at an angle so high that it could be misinterpreted as a fault. We thus conclude that the syn-extension strata were deposited on a surface with very rugged topography. We also discovered that locally-derived nonmarine gravel deposits exposed near the crest of the range, previously interpreted as part of the Miocene Split Mountain Group by Winker and Kidwell (1996), unconformably overlie units of the marine Miocene/Pliocene Imperial Group and must therefore be Pliocene or younger. The presence of such young gravel deposits on the crest of the range provides evidence for its rapid uplift. Additional new discoveries flesh out details of the structural history of the range. We mapped just two normal faults, both of which were relatively minor, thus supporting Axen and Fletcher's assertion that the hanging wall block of the Salton Detachment Fault had not undergone significant internal deformation during extension. We found abundant complex synthetic and antithetic strike-slip faults throughout the area, some of which offset Quaternary alluvial

  13. Dynamic Rupture Models of Earthquakes on the Bartlett Springs Fault, Northern California (United States)

    Lozos, J.; Harris, R.; Murray, J. R.; Lienkaemper, J. J.; Abrahamson, N. A.


    The Bartlett Springs Fault is a major right-lateral component of the San Andreas fault system in northern California. Fault slip-rate models inferred from GPS data [Murray et al., 2013] and alignment array data [McFarland et al., 2009] both indicate that the Bartlett Springs fault experiences aseismic creep. We use the three-dimensional finite element computer code of Barall [2009] to conduct models of dynamic spontaneous rupture on this fault, both to determine characteristics of potential earthquakes, and to gauge the ability of rupture to propagate in the creeping regions. Within the framework of slip-weakening friction, we represent locked portions of the fault as regions of positive stress drop, and creeping regions as having zero or negative stress drop. Using the fault geometry and creep distribution from studies by Murray et al., we examine simulations that implement either homogeneous initial stresses or a regional stress field, along with several different parameterizations of the contrast in frictional properties between locked and creeping zones. We compare the earthquake source characteristics for the same fault geometry with and without the known creeping sections. These comparisons can be used to estimate the impacts of the creeping sections on ground motion predictions.

  14. Ground motion modeling of the 1906 San Francisco earthquake II: Ground motion estimates for the 1906 earthquake and scenario events

    Energy Technology Data Exchange (ETDEWEB)

    Aagaard, B; Brocher, T; Dreger, D; Frankel, A; Graves, R; Harmsen, S; Hartzell, S; Larsen, S; McCandless, K; Nilsson, S; Petersson, N A; Rodgers, A; Sjogreen, B; Tkalcic, H; Zoback, M L


    We estimate the ground motions produced by the 1906 San Francisco earthquake making use of the recently developed Song et al. (2008) source model that combines the available geodetic and seismic observations and recently constructed 3D geologic and seismic velocity models. Our estimates of the ground motions for the 1906 earthquake are consistent across five ground-motion modeling groups employing different wave propagation codes and simulation domains. The simulations successfully reproduce the main features of the Boatwright and Bundock (2005) ShakeMap, but tend to over predict the intensity of shaking by 0.1-0.5 modified Mercalli intensity (MMI) units. Velocity waveforms at sites throughout the San Francisco Bay Area exhibit characteristics consistent with rupture directivity, local geologic conditions (e.g., sedimentary basins), and the large size of the event (e.g., durations of strong shaking lasting tens of seconds). We also compute ground motions for seven hypothetical scenarios rupturing the same extent of the northern San Andreas fault, considering three additional hypocenters and an additional, random distribution of slip. Rupture directivity exerts the strongest influence on the variations in shaking, although sedimentary basins do consistently contribute to the response in some locations, such as Santa Rosa, Livermore, and San Jose. These scenarios suggest that future large earthquakes on the northern San Andreas fault may subject the current San Francisco Bay urban area to stronger shaking than a repeat of the 1906 earthquake. Ruptures propagating southward towards San Francisco appear to expose more of the urban area to a given intensity level than do ruptures propagating northward.

  15. [Andreas Vesalius and surgery]. (United States)

    Van Hee, R


    By publishing De Humani Corporis Fabrica Libri Septem in 1543, Andries van Wesel (1514-1564) gave surgical science an immense impulse. The revolutionary renovation in the knowledge of man's anatomical structure changed slowly and progressively into topographical and physiological understanding of surgical diseases. At the same time, this made better aimed and more secure operations possible. Apart from the importance of this anatomical publication, Andreas Vesalius also won his spurs as a surgeon. He taught surgery in Padua for many years. He was appointed court physician and surgeon at the Habsburg Court of Charles V and Philip II. He personally performed lots of operations known at the time as major ones. He not only quickly adopted the surgical innovations of his fellow-surgeon Ambroise Paré, but he even performed operations that had been forgotten during several centuries, among which thoracocentesis for pleural empyema. His clinical perspicacity in discovering the indication for some operations was staggering and was appreciated by all great monarchs of Europe in the 16th century. In his several consilia, numerous pieces of advice were given for the treatment of surgical patients. The surgical practice which Vesalius had in Brussels for many years, consequently became most successful. Many publications by Vesalius about surgery and blood-letting are well-known. His Chirurgia magna in septem Libros digesta still remains controversial; these books were published by Prospero Borgarruccio (1560) in 1568 by the Venetian editor Valgrisi. This book gives an excellent survey of surgical pathology as it was taught and treated in the 16th century. The scientific method that Vesalius used, not only in his anatomical studies but also in his surgical practice, deserves not only our full appraisal but should still be studied in our own time.

  16. Resource investigation of low- and moderate-temperature geothermal areas in San Bernardino, California. Part of the third year report, 1980-81, of the US Department of Energy-California State-Coupled Program for Reservoir Assessment and Confirmation

    Energy Technology Data Exchange (ETDEWEB)

    Youngs, L.G.; Bezore, S.P.; Chapman, R.H.; Chase, G.W.


    Ninety-seven geothermal wells and springs were identified and plotted on a compiled geologic map of the 40-square-mile study area. These wells and springs were concentrated in three distinguishable resource areas: Arrowhead Hot Springs; South San Bernardino; and Harlem Hot Springs - in each of which detailed geophysical, geochemical, and geological surveys were conducted. The Arrowhead Hot Springs geothermal area lies just north of the City of San Bernardino in the San Bernardino Mountains astride a shear zone (offshoot of the San Andreas fault) in pre-Cambrian gneiss and schist. The Harlem Hot Springs geothermal area, on the east side of the City, and the south San Bernardino geothermal area, on the south side, have geothermal reservoirs in Quaternary alluvial material which overlies a moderately deep sedimentary basin bound on the southwest by the San Jacinto fault (a ground water barrier). Geothermometry calculations suggest that the Arrowhead Hot Springs geothermal area, with a maximum reservoir temperature of 142/sup 0/C, may have the highest maximum reservoir temperature of the three geothermal areas. The maximum temperature recorded by CDMG in the south San Bernardino geothermal area was 56/sup 0/C from an artesian well, while the maximum temperature recorded in the Harlem Hot Springs geothermal area was 49.5/sup 0/C at 174 meters (570 feet) in an abandoned water well. The geophysical and geological surveys delineated fault traces in association with all three of the designated geothermal areas.

  17. Andreas Struppleri intelligentsed rakendused / Andreas Struppler ; interv. Margit Aedla

    Index Scriptorium Estoniae

    Struppler, Andreas


    Disainer Andreas Struppler (sünd. 1964) enda ja oma meeskonna loodud e-mood'i sarja vannitoast, valgustusest vannitoas. Privaatala eraldamiseks ülejäänud vannitoast suunatakse värviline valgus keraamiliselt trükitud klaaspaneelile. E-sirm on ruumijagaja moodne tõlgendus

  18. A bottom-driven mechanism for distributed faulting in the Gulf of California rift (United States)

    Persaud, Patricia; Tan, Eh; Contreras, Juan; Lavier, Luc


    Observations of active faulting in the continent-ocean transition of the Northern Gulf of California show multiple oblique-slip faults distributed in a 200 × 70 km2 area developed some time after a westward relocation of the plate boundary at 2 Ma. In contrast, north and south of this broad pull-apart structure, major transform faults accommodate Pacific-North America plate motion. Here we propose that the mechanism for distributed brittle deformation results from the boundary conditions present in the Northern Gulf, where basal shear is distributed between the Cerro Prieto strike-slip fault (southernmost fault of the San Andreas fault system) and the Ballenas Transform Fault. We hypothesize that in oblique-extensional settings whether deformation is partitioned in a few dip-slip and strike-slip faults, or in numerous oblique-slip faults may depend on (1) bottom-driven, distributed extension and shear deformation of the lower crust or upper mantle, and (2) the rift obliquity. To test this idea, we explore the effects of bottom-driven shear on the deformation of a brittle elastic-plastic layer with the help of pseudo-three dimensional numerical models that include side forces. Strain localization results when the basal shear abruptly increases in a step-function manner while oblique-slip on numerous faults dominates when basal shear is distributed. We further explore how the style of faulting varies with obliquity and demonstrate that the style of delocalized faulting observed in the Northern Gulf of California is reproduced in models with an obliquity of 0.7 and distributed basal shear boundary conditions, consistent with the interpreted obliquity and boundary conditions of the study area.

  19. Neogene folding and faulting in southern Monterey Bay, Central California, USA (United States)

    Gardner-Taggart, J. M.; Greene, H. Gary; Ledbetter, M.T.


    The goal of this study was to determine the Neogene structural history of southern Monterey Bay by mapping and correlating the shallow tectonic structures with previously identified deeper occurring structures. Side scan sonographs and Uniboom seismic reflection profiles collected in the region suggest that deformation associated with both compressional and transcurrent movement is occurring. Strike-slip movement between the North American and Pacific plates started as subduction ceased 21 Ma, creating the San Andreas fault system. Clockwise rotation of the Pacific plate occurred between 3.4 and 3.9 Ma causing orthogonal convergence between the two plates. This plate rotation is responsible for compressional Neogene structures along the central California coast. Structures exhibit transpressional tectonic characteristics such as thrust faulting, reverse faulting and asymmetrical folding. Folding and faulting are confined to middle Miocene and younger strata. Shallow Mesozoic granitic basement rocks either crop out or lie near the surface in most of the region and form a possible de??collement along which the Miocene Monterey Formation has decoupled and been folded. Over 50% of the shallow faults strike normal (NE-SW) to the previously identified faults. Wrench fault tectonics complicated by compression, gradual uplift of the basement rocks, and a change in plate convergence direction are responsible for the observed structures in southern Monterey Bay. ?? 1993.

  20. Geologic map of the Palo Alto and part of the Redwood Point 7-1/2' quadrangles, San Mateo and Santa Clara counties, California (United States)

    Pampeyan, Earl H.


    The Palo Alto and southern part of the Redwood Point 7-1/2' quadrangles cover an area on the San Francisco peninsula between San Francisco Bay and the Santa Cruz Mountains. San Francisquito and Los Trancos Creeks, in the southeastern part of the map area, form the boundary between San Mateo and Santa Clara Counties. The area covered by the geologic map extends from tidal and marsh lands at the edge of the bay southward across a gently sloping alluvial plain to the foothills of the northern Santa Cruz Mountains. The foothills are separated from the main mass of the mountains by two northwest-striking faults, the San Andreas and Pilarcitos, that cross the southwest corner of the map area (fig. 1). The map and adjoining areas are here divided into three structural blocks juxtaposed along these faults, adopting the scheme of Nilsen and Brabb (1979): (1) the San Francisco Bay block lying east of the San Andreas Fault Zone; (2) the Pilarcitos block lying between the San Andreas and Pilarcitos Faults; and (3) the La Honda block that includes the main mass of the Santa Cruz Mountains lying west of the Pilarcitos Fault. The west boundary of the La Honda block is the Seal Cove-San Gregorio Fault. Pre-late Pleistocene Cenozoic rocks of the foothills have been compressed into northwest-striking folds, which have been overridden by Mesozoic rocks along southwest-dipping low-angle faults. Coarse- to fine-grained upper Pleistocene and Holocene alluvial and estuarine deposits, eroded from the foothills and composing the alluvial plain, are essentially undeformed. Most of the alluvial plain, including some parts of the marsh land that borders the bay, has been covered by residential and commercial developments, and virtually all of the remaining marsh land has been diked off and used as salt evaporating ponds. The map area includes parts of the municipalities of San Carlos, Redwood City, Atherton, Woodside, Portola Valley, Menlo Park, and East Palo Alto in San Mateo County; and

  1. How do "ghost transients" from past earthquakes affect GPS slip rate estimates on southern California faults? (United States)

    Hearn, E. H.; Pollitz, F. F.; Thatcher, W. R.; Onishi, C. T.


    In this study, we investigate the extent to which viscoelastic velocity perturbations (or "ghost transients") from individual fault segments can affect elastic block model-based inferences of fault slip rates from GPS velocity fields. We focus on the southern California GPS velocity field, exploring the effects of known, large earthquakes for two end-member rheological structures. Our approach is to compute, at each GPS site, the velocity perturbation relative to a cycle average for earthquake cycles on particular fault segments. We then correct the SCEC CMM4.0 velocity field for this perturbation and invert the corrected field for fault slip rates. We find that if asthenosphere viscosities are low (3 × 1018 Pa s), the current GPS velocity field is significantly perturbed by viscoelastic earthquake cycle effects associated with the San Andreas Fault segment that last ruptured in 1857 (Mw = 7.9). Correcting the GPS velocity field for this perturbation (or "ghost transient") adds about 5 mm/a to the SAF slip rate along the Mojave and San Bernardino segments. The GPS velocity perturbations due to large earthquakes on the Garlock Fault (most recently, events in the early 1600s) and the White Wolf Fault (most recently, the Mw = 7.3 1952 Kern County earthquake) are smaller and do not influence block-model inverted fault slip rates. This suggests that either the large discrepancy between geodetic and geologic slip rates for the Garlock Fault is not due to a ghost transient or that un-modeled transients from recent Mojave earthquakes may influence the GPS velocity field.

  2. Pärnograafiline / Andreas Trossek

    Index Scriptorium Estoniae

    Trossek, Andreas, 1980-


    Priit Pärna näitus Kumu Kunstimuuseumis kuni 21. X. Kuraator Eha Komissarov. 11. V toimus Kumu auditooriumis Priit Pärna loomingule pühendatud rahvusvaheline seminar, peaesinejaks oli Edwin Carels Belgiast. Esitamisele tuli filmiprogramm Priit Pärna filmidest ning toimus ümarlaud, milles osalesid Andreas Trossek, Mari Laaniste ja Priit Pärn

  3. Constraining Basin Geometry and Fault Kinematics on the Santo Tomas Segment of the Agua Blanca Fault Through a Combined Geophysical and Structural Study (United States)

    Springer, A.; Wetmore, P.; Fletcher, J.; Connor, C. B.; Callihan, S.; Beeson, J.; Wilson, J.


    The Santo Tomas basin, located in northern Baja California, formed at a right step in the dextral Agua Blanca fault (ABF). The ABF extends for more than 120km east from Punta Banda, with an east-west strike, and represents the southernmost fault in the San Andreas system of faulting. The basin is located roughly 40km south of Ensenada where the Agua Blanca fault intersects the Maximos fault. A detailed geophysical analysis defines the basin geometry, and helps to constrain the distribution and offset of mapped and concealed faults. Geophysical and structural data sets are combined to constrain the kinematic evolution of the Santo Tomas basin, including determining the relative amount of dip-slip and strike-slip motion on basin-bounding faults. Gravity data was collected over seven transects across and along the axis of the basin at 500 meter intervals, with 200 meter intervals at locations of known or inferred faults. Magnetic data were taken over the same lines, and are used in conjunction with gravity data to constrain the locations, geometries and displacements of intrabasinal faults. The combined gravity and magnetic data are modeled using Geosoft Oasis montaj software to create 2 3/4D models along profiles across the study area. Modeling of the geophysical data combined with structural mapping indicates that the Santo Tomas basin is bound by two major strike-slip faults, the ABF on the northeastern side and the Maximos fault on south, Based on offset markers, most of the strike-slip motion appears to be concentrated on the ABF on the north side of the basin. The ABF fault is characterized by multiple subparallel fault strands that appear to coalesce into single strands to the northwest and southeast of the basin. The Maximos is characterized by a single strand throughout the basin and it exhibits a minor dip-slip component. Basin sediments thicken slightly against the Maximos fault to as much as 1km. A third fault, cutting across the basin southeast of the

  4. Morphotectonic and structural analysis of the municipalities of San Cristóbal and Candelaria, Western Cuba: contribution to seismic hazard studies of Pinar Fault

    Directory of Open Access Journals (Sweden)

    Alexis Ordaz Hernández


    Full Text Available The research focuses on revealing the main morphotectonic expressions of relief, as a contribution to the study of moderate seismicity of territory. Morphostructural analysis combined with results of analysis of structures, to mesoscopic scale, provide elements of the preferred direction of the tectonic forces that determined the contemporary re lief. A total of 44 outcrops were described and 686 structural elements measured (extension fracture, shear and hybrid fracture, axes and axial planes of folds. Morphotectonics interpretations and geomorphological indexes allowed to reveal morphostructural block differentiation, transverse to Pinar transcurrent fault, with potential seismogenic character and also conclude on the main and subordinate directions of tectonic efforts which generated the substrate’s mesostructures and the relief ’s morphostructures, significant parameters in characterizing regional seismotectonics. Special attention deserves the “back pressure” generated on the Pinar fault trace, located to north of La Conchita, which present a differentiation in stepped microblocks and displaced horizontally, indicating a remarkable deformation with characteristics seismic hazard for San Cristóbal and Candelaria towns.

  5. Spatial and temporal variation of fault slip and distributed off-fault deformation, Santa Cruz Mountains, central California (United States)

    Horsman, E. M.; Graymer, R. W.


    The Santa Cruz Mountains of central California record a lengthy history of deformation, including slip on the dextral San Andreas Fault (SAF) system and off-fault deformation manifested by both slip on secondary faults as well as distributed strain. This complex history provides insight into regional deformation processes operating both before and after initiation of the SAF. We focus here on deformation SW of the SAF, where several distinct, fault-bounded crustal blocks record different histories. We evaluate the magnitude and significance of off-fault deformation SW of the SAF by considering spatial and temporal relationships between slip on secondary faults and distributed deformation. To conduct the analysis we combine a synthesis of the slip histories of five important regional faults with a new dataset constraining spatial and temporal variation of regional deformation magnitude. This new dataset is based on shortening measurements of several major unconformities compiled from more than 60 cross sections from the region. To estimate strain magnitude recorded by older surfaces, we progressively subtract shortening magnitude of young markers from older markers. Because uncertainties grow for older surfaces, this method is most reliable for younger surfaces. Results of the analysis demonstrate that strain magnitude recorded by several unconformity-bound sedimentary packages of different ages is largest within about 5 km of the SAF, providing evidence of long-term deformation partitioning near this major structure. This pattern of distributed deformation partitioning near faults is also apparent but less pronounced near the secondary faults SW of the SAF. When considering spatial and temporal ties between regional deformation and slip on secondary faults, no simple pattern emerges. Fault activity is highly variable in both space and time. Additionally, fault activity at any one time is highly localized; one fault may be active while a nearby structure is inactive

  6. Age and isotopic systematics of Cretaceous borehole and surface samples from the greater Los Angeles Basin region: Implications for the types of crust that might underlie Los Angeles and their distribution along late Cenozoic fault systems (United States)

    Premo, Wayne R.; Morton, Douglas M.; Kistler, Ronald W.


    Nine U-Pb zircon ages were determined on plutonic rocks sampled from surface outcrops and rock chips of drill core from boreholes within the greater Los Angeles Basin region. In addition, lead-strontium-neodymium (Pb-Sr-Nd) whole-rock isotopic data were obtained for eight of these samples. These results help to characterize the crystalline basement rocks hidden in the subsurface and provide information that bears on the tectonic history of the myriad of fault systems that have dissected the Los Angeles region over the past 15 m.y. Seven of the nine samples have U-Pb ages ranging from 115 to 103 Ma and whole-rock Pb-Sr-Nd isotopic characteristics that indicate the crystalline basement underneath the greater Los Angeles Basin region is mostly part of the Peninsular Ranges batholith. Furthermore, these data are interpreted as evidence for (1) the juxtaposition of mid-Cretaceous, northern Peninsular Ranges batholith plutonic rocks against Late Cretaceous plutonic rocks of the Transverse Ranges in the San Fernando Valley, probably along the Verdugo fault; (2) the juxtaposition of older northwestern Peninsular Ranges batholith rocks against younger northeastern Peninsular Ranges batholith rocks in the northern Puente Hills, implying transposition of northeastern Peninsular Ranges batholith rocks to the west along unrecognized faults beneath the Chino Basin; and (3) juxtaposition of northern Peninsular Ranges batholith plutonic rocks against Late Cretaceous plutonic rocks of the Transverse Ranges along the San Jose fault in the northern San Jose Hills at Ganesha Park. These mainly left-lateral strike-slip faults of the eastern part of the greater Los Angeles Basin region could be the result of block rotation within the adjacent orthogonal, right-lateral, Elsinore-Whittier fault zone to the west and the subparallel San Jacinto fault zone to the east. The San Andreas fault system is the larger, subparallel, driving force further to the east.

  7. Multi-method Feasibility Study of Geophysical Methods to Accurately Delineate the Mt. General Fault in Hinkley, CA (United States)

    Jordan, J. J.; Grannell, R.; Martin, A. J.


    Barstow, California is in the immediate vicinity of the dextral Mt. General, Lenwood and Harper Lake faults.These faults exhibit a lack of surface expression common to faults in the Central Mojave, in which the faults are occluded by Quaternary alluvial fill resulting in large sections of the fault strand to be inferred near high risk localities. The three quaternary right-lateral strike slip faults belong to the Lenwood-Lockhart and Harper Lake fault zones. These fault zones associated with the Eastern California Shear Zone, a predominantly discontinuous northwest striking dextral shear zone that accommodates approximately 25% of interplate motion along the Pacific and North American plate boundary from the San Andreas bend on the south and Walker Lane shear zone to the northwest. The proximity of the inferred fault to high density population centers and critical infrastructure pose considerable risk to the inhabitants of Southern California, where precise knowledge of fault locations is critical. A feasibility study using various complementary geophysical methods was conducted to assess which, if any, provide the highest likelihood in accurately delineating a fault trace in the subsurface. The study focused on the Mt. General fault in Hinkley, CA. Two-dimensional gravity, magnetic, seismic refraction, and electrical resistivity along the same bounded location were collected, modeled, and interpreted. Gravity and magnetic results revealed anomalies across the inferred fault. Likewise, a seismic refraction model show a clear velocity contrast. Additionally, the electrical resistivity model showed a decrease in resistivity across the fault zone implying a groundwater barrier, complementing results from the other methods. Furthermore, overlaying the profiles shows clear evidence of a fault scarp. The success of the feasibility study in delineating the Mt. General fault zone shows that adopting a multi-method approach to the Lenwood-Lockhart and Harper Lake fault zone

  8. Dr Andrea Granelli, Vice President, Telecom Italia

    CERN Multimedia

    Patrice Loïez


    Photo 06: Dr Andrea Granelli, Chief Executive Officer, Telecom Italia Lab (second from right) visiting the LHC superconducting magnet test hall with (from left to right) M. Cecchi , F. Gagliardi and G. Cavallari. Photo 15: Dr Andrea Granelli, Chief Executive Officer, Telecom Italia Lab (left) visiting the LHC superconducting magnet test hall with (from left to right) M. Cecchi and G. Cavallari.

  9. Explaining the current geodetic field with geological models: A case study of the Haiyuan fault system (United States)

    Daout, S.; Jolivet, R.; Lasserre, C.; Doin, M. P.; Barbot, S.; Peltzer, G.; Tapponnier, P.


    Oblique convergence across Tibet leads to slip partitioning with the co-existence of strike-slip, normal and thrust motion in major fault systems. While such complexity has been shown at the surface, the question is to understand how faults interact and accumulate strain at depth. Here, we process InSAR data across the central Haiyuan restraining bend, at the north-eastern boundary of the Tibetan plateau and show that the surface complexity can be explained by partitioning of a uniform deep-seated convergence rate. We construct a time series of ground deformation, from Envisat radar data spanning from 2001-2011 period, across a challenging area because of the high jump in topography between the desert environment and the plateau. To improve the signal-to-noise ratio, we used the latest Synthetic Aperture Radar interferometry methodology, such as Global Atmospheric Models (ERA Interim) and Digital Elevation Model errors corrections before unwrapping. We then developed a new Bayesian approach, jointly inverting our InSAR time series together with published GPS displacements. We explore fault system geometry at depth and associated slip rates and determine a uniform N86±7E° convergence rate of 8.45±1.4 mm/yr across the whole fault system with a variable partitioning west and east of a major extensional fault-jog. Our 2D model gives a quantitative understanding of how crustal deformation is accumulated by the various branches of this thrust/strike-slip fault system and demonstrate the importance of the geometry of the Haiyuan Fault, controlling the partitioning or the extrusion of the block motion. The approach we have developed would allow constraining the low strain accumulation along deep faults, like for example for the blind thrust faults or possible detachment in the San Andreas "big bend", which are often associated to a poorly understood seismic hazard.

  10. Counter-intuitive Behavior of Subduction Zones: Weak Faults Rupture, Strong Faults Creep (United States)

    Wang, K.; Gao, X.; Bilek, S. L.; Brown, L. N.


    San Andreas fault. The general correlation between subducting seafloor ruggedness, creeping, and greater heat dissipation, if further verified, provides a new perspective in assessing earthquake and tsunami hazards for risk mitigation. Wang, K., and S. L. Bilek. Tectonophysics 610, 1-24 (2014).

  11. Effects of fluid-rock interactions on faulting within active fault zones - evidence from fault rock samples retrieved from international drilling projects (United States)

    Janssen, C.; Wirth, R.; Kienast, M.; Yabe, Y.; Sulem, J.; Dresen, G. H.


    Chemical and mechanical effects of fluids influence the fault mechanical behavior. We analyzed fresh fault rocks from several scientific drilling projects to study the effects of fluids on fault strength. For example, in drill core samples on a rupture plane of an Mw 2.2 earthquake in a deep gold mine in South Africa the main shock occurred on a preexisting plane of weakness that was formed by fluid-rock interaction (magnesiohornblende was intensively altered to chlinochlore). The plane acted as conduit for hydrothermal fluids at some time in the past. The chemical influence of fluids on mineralogical alteration and geomechanical processes in fault core samples from SAFOD (San Andreas Fault Observatory at Depth) is visible in pronounced dissolution-precipitation processes (stylolites, solution seams) as well as in the formation of new phases. Detrital quartz and feldspar grains are partially dissolved and replaced by authigenic illite-smectite (I-S) mixed-layer clay minerals. Transmission Electron Microscopy (TEM) imaging of these grains reveals that the alteration processes and healing were initiated within pores and small intra-grain fissures. Newly formed phyllosilicates growing into open pore spaces likely reduced the fluid permeability. The mechanical influence of fluids is indicated by TEM observations, which document open pores that formed in-situ in the gouge material during or after deformation. Pores were possibly filled with formation water and/or hydrothermal fluids suggesting elevated fluid pressure preventing pore collapse. Fluid-driven healing of fractures in samples from SAFOD and the DGLab Gulf of Corinth project is visible in cementation. Cathodoluminescence microscopy (CL) reveals different generations of calcite veins. Differences in CL-colors suggest repeated infiltration of fluids with different chemical composition from varying sources (formation and meteoric water).

  12. Library holdings for Cradle of the Earthquake: Exploring the Underwater San Andreas Fault on the R/V Pacific Storm and the SRV Derek M. Baylis in the North Pacific Ocean between September 10, 2010 and October 3, 2010 (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Library Catalog may include: Data Management Plans, Cruise Plans, Cruise Summary Reports, Scientific "Quick Look Reports", Video Annotation Logs, Image Collections,...

  13. Tidal triggering of low frequency earthquakes near Parkfield, California: Implications for fault mechanics within the brittle-ductile transition (United States)

    Thomas, A.M.; Burgmann, R.; Shelly, David R.; Beeler, Nicholas M.; Rudolph, M.L.


    Studies of nonvolcanic tremor (NVT) have established the significant impact of small stress perturbations on NVT generation. Here we analyze the influence of the solid earth and ocean tides on a catalog of ∼550,000 low frequency earthquakes (LFEs) distributed along a 150 km section of the San Andreas Fault centered at Parkfield. LFE families are identified in the NVT data on the basis of waveform similarity and are thought to represent small, effectively co-located earthquakes occurring on brittle asperities on an otherwise aseismic fault at depths of 16 to 30 km. We calculate the sensitivity of each of these 88 LFE families to the tidally induced right-lateral shear stress (RLSS), fault-normal stress (FNS), and their time derivatives and use the hypocentral locations of each family to map the spatial variability of this sensitivity. LFE occurrence is most strongly modulated by fluctuations in shear stress, with the majority of families demonstrating a correlation with RLSS at the 99% confidence level or above. Producing the observed LFE rate modulation in response to shear stress perturbations requires low effective stress in the LFE source region. There are substantial lateral and vertical variations in tidal shear stress sensitivity, which we interpret to reflect spatial variation in source region properties, such as friction and pore fluid pressure. Additionally, we find that highly episodic, shallow LFE families are generally less correlated with tidal stresses than their deeper, continuously active counterparts. The majority of families have weaker or insignificant correlation with positive (tensile) FNS. Two groups of families demonstrate a stronger correlation with fault-normal tension to the north and with compression to the south of Parkfield. The families that correlate with fault-normal clamping coincide with a releasing right bend in the surface fault trace and the LFE locations, suggesting that the San Andreas remains localized and contiguous down

  14. 3D Dynamic Rupture Simulation Across a Complex Fault System: the Mw7.0, 2010, Haiti Earthquake (United States)

    Douilly, R.; Aochi, H.; Calais, E.; Freed, A. M.


    Earthquakes ruptures sometimes take place on a secondary fault and surprisingly do not activate an adjacent major one. The 1989 Loma Prieta earthquake is a classic case where rupture occurred on a blind thrust while the adjacent San Andreas Fault was not triggered during the process. Similar to Loma Prieta, the Mw7.0, January 12 2010, Haiti earthquake also ruptured a secondary blind thrust, the Léogâne fault, adjacent to the main plate boundary, the Enriquillo Plantain Garden Fault, which did not rupture during this event. Aftershock relocalizations delineate the Léogâne rupture with two north dipping segments with slightly different dip, where the easternmost segment had mostly dip-slip motion and the westernmost one had mostly strike-slip motion. In addition, an offshore south dipping structure inferred from the aftershocks to the west of the rupture zone coincides with the offshore Trois Baies reverse fault, a region of increase in Coulomb stress increase. In this study, we investigate the rupture dynamics of the Haiti earthquake in a complex fault system of multiple segments identified by the aftershock relocations. We suppose a background stress regime that is consistent with the type of motion of each fault and with the regional tectonic regime. We initiate a nucleation on the east segment of the Léogâne fault by defining a circular region with a 2 km radius where shear stress is slightly greater than the yield stress. By varying friction on faults and background stress, we find a range of plausible scenarios. In the absence of near-field seismic records of the event, we score the different models against the static deformation field derived from GPS and InSAR at the surface. All the plausible simulations show that the rupture propagates from the eastern to the western segment along the Léogâne fault, but not on the Enriquillo fault nor on the Trois Baies fault. The best-fit simulation shows a significant increase of shear stresses on the Trois Baies

  15. Effects of Channel Modification on Detection and Dating of Fault Scarps (United States)

    Sare, R.; Hilley, G. E.


    Template matching of scarp-like features could potentially generate morphologic age estimates for individual scarps over entire regions, but data noise and scarp modification limits detection of fault scarps by this method. Template functions based on diffusion in the cross-scarp direction may fail to accurately date scarps near channel boundaries. Where channels reduce scarp amplitudes, or where cross-scarp noise is significant, signal-to-noise ratios decrease and the scarp may be poorly resolved. In this contribution, we explore the bias in morphologic age of a complex scarp produced by systematic changes in fault scarp curvature. For example, fault scarps may be modified by encroaching channel banks and mass failure, lateral diffusion of material into a channel, or undercutting parallel to the base of a scarp. We quantify such biases on morphologic age estimates using a block offset model subject to two-dimensional linear diffusion. We carry out a synthetic study of the effects of two-dimensional transport on morphologic age calculated using a profile model, and compare these results to a well- studied and constrained site along the San Andreas Fault at Wallace Creek, CA. This study serves as a first step towards defining regions of high confidence in template matching results based on scarp length, channel geometry, and near-scarp topography.

  16. Radar Determination of Fault Slip and Location in Partially Decorrelated Images (United States)

    Parker, Jay; Glasscoe, Margaret; Donnellan, Andrea; Stough, Timothy; Pierce, Marlon; Wang, Jun


    Faced with the challenge of thousands of frames of radar interferometric images, automated feature extraction promises to spur data understanding and highlight geophysically active land regions for further study. We have developed techniques for automatically determining surface fault slip and location using deformation images from the NASA Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR), which is similar to satellite-based SAR but has more mission flexibility and higher resolution (pixels are approximately 7 m). This radar interferometry provides a highly sensitive method, clearly indicating faults slipping at levels of 10 mm or less. But interferometric images are subject to decorrelation between revisit times, creating spots of bad data in the image. Our method begins with freely available data products from the UAVSAR mission, chiefly unwrapped interferograms, coherence images, and flight metadata. The computer vision techniques we use assume no data gaps or holes; so a preliminary step detects and removes spots of bad data and fills these holes by interpolation and blurring. Detected and partially validated surface fractures from earthquake main shocks, aftershocks, and aseismic-induced slip are shown for faults in California, including El Mayor-Cucapah (M7.2, 2010), the Ocotillo aftershock (M5.7, 2010), and South Napa (M6.0, 2014). Aseismic slip is detected on the San Andreas Fault from the El Mayor-Cucapah earthquake, in regions of highly patterned partial decorrelation. Validation is performed by comparing slip estimates from two interferograms with published ground truth measurements.

  17. Imaging the North Anatolian Fault using the scattered teleseismic wavefield (United States)

    Thompson, D. A.; Rost, S.; Houseman, G. A.; Cornwell, D. G.; Turkelli, N.; Teoman, U.; Kahraman, M.; Altuncu Poyraz, S.; Gülen, L.; Utkucu, M.; Frederiksen, A. W.; Rondenay, S.


    The North Anatolian Fault Zone (NAFZ) is a major continental strike-slip fault system, similar in size and scale to the San Andreas system, that extends ˜1200 km across Turkey. In 2012, a new multidisciplinary project (FaultLab) was instigated to better understand deformation throughout the entire crust in the NAFZ, in particular the expected transition from narrow zones of brittle deformation in the upper crust to possibly broader shear zones in the lower crust/upper mantle and how these features contribute to the earthquake loading cycle. This contribution will discuss the first results from the seismic component of the project, a 73 station network encompassing the northern and southern branches of the NAFZ in the Sakarya region. The Dense Array for North Anatolia (DANA) is arranged as a 6×11 grid with a nominal station spacing of 7 km, with a further 7 stations located outside of the main grid. With the excellent resolution afforded by the DANA network, we will present images of crustal structure using the technique of teleseismic scattering tomography. The method uses a full waveform inversion of the teleseismic scattered wavefield coupled with array processing techniques to infer the properties and location of small-scale heterogeneities (with scales on the order of the seismic wavelength) within the crust. We will also present preliminary results of teleseismic scattering migration, another powerful method that benefits from the dense data coverage of the deployed seismic network. Images obtained using these methods together with other conventional imaging techniques will provide evidence for how the deformation is distributed within the fault zone at depth, providing constraints that can be used in conjunction with structural analyses of exhumed fault segments and models of geodetic strain-rate across the fault system. By linking together results from the complementary techniques being employed in the FaultLab project, we aim to produce a comprehensive

  18. Active tectonic deformation of the western Indian plate boundary: A case study from the Chaman Fault System (United States)

    Crupa, Wanda E.; Khan, Shuhab D.; Huang, Jingqiu; Khan, Abdul S.; Kasi, Aimal


    Collision of the Eurasian and Indian plates has resulted in two spatially offset subduction zones, the Makran subduction zone to the south and the Himalayan convergent margin to the north. These zones are linked by a system of left-lateral strike-slip faults known as the Chaman Fault System, ∼1200 km, which spans along western Pakistan. Although this is one of the greatest strike-slip faults, yet temporal and spatial variation in displacement has not been adequately defined along this fault system. This study conducted geomorphic and geodetic investigations along the Chaman Fault in a search for evidence of spatial variations in motion. Four study areas were selected over the span of the Chaman Fault: (1) Tarnak-Rud area over the Tarnak-Rud valley, (2) Spinatizha area over the Spinatizha Mountain Range, (3) Nushki area over the Nushki basin, and (4) Kharan area over the northern tip of the Central Makran Mountains. Remote sensing data allowed for in depth mapping of different components and faults within the Kohjak group. Wind and water gap pairs along with offset rivers were identified using high-resolution imagery and digital-elevation models to show displacement for the four study areas. The mountain-front-sinuosity ratio, valley height-to-width-ratio, and the stream-length-gradient index were calculated and used to determine the relative tectonic activity of each area. These geomorphic indices suggest that the Kharan area is the most active and the Tarnak-Rud area is the least active. GPS data were processed into a stable Indian plate reference frame and analyzed. Fault parallel velocity versus fault normal distance yielded a ∼8-10 mm/yr displacement rate along the Chaman Fault just north of the Spinatizha area. InSAR data were also integrated to assess displacement rates along the fault system. Geodetic data support that ultra-slow earthquakes similar to those that strike along other major strike-slip faults, such as the San Andreas Fault System, are

  19. Tectonic inheritance, reactivation and long term fault weakening processes (United States)

    Holdsworth, Bob


    This talk gives a geological review of weakening processes in faults and their long-term effect on reactivation and tectonic inheritance during crustal deformation. Examples will be drawn from the Atlantic margins, N America, Japan and the Alps. Tectonic inheritance and reactivation are fundamentally controlled by the processes of stress concentration and shear localisation manifested at all scales in the continental lithosphere. Lithosphere-scale controls include crustal thickness, thermal age and the boundary conditions imposed by the causative plate tectonic processes during extension. At the other end of the scale range, grain-scale controls include local environmental controls (depth, stress, strain rate), rock composition, grainsize, fabric intensity and the presence of fluids or melt. Intermediate-scale geometric controls are largely related to the size, orientation and interconnectivity of pre-existing anisotropies. If reactivation of pre-existing structures occurs, it likely requires a combination of processes across all three scale ranges to be favourable. This can make the unequivocal recognition of inheritance and reactivation difficult. Large (e.g. crustal-scale) pre-existing structures are especially important due to their ability to efficiently concentrate stress and localise strain. For big faults (San Andreas, Great Glen, Median Tectonic Line), detailed studies of the associated exposed fault rocks indicate that reactivation is linked to the development of strongly anisotropic phyllosilicate-rich fault rocks that are weak (e.g. friction coefficients as low as 0.2 or less) under a broad range of deformation conditions. In the case of pre-existing regional dyke swarms (S Atlantic, NW Scotland) - which may themselves track deep mantle fabrics at depth - multiple reactivation of dyke margins is widespread and may preclude reactivation of favourably oriented local basement fabrics. In a majority of cases, pre-existing structures in the crust are

  20. Preliminary geologic map of the San Guillermo Mountain Quadrangle, Ventura County, California (United States)

    Minor, S.A.


    New 1:24,000-scale geologic mapping in the Cuyama 30' x 60' quadrangle, in support of the USGS Southern California Areal Mapping Project (SCAMP), is contributing to a more complete understanding of the stratigraphy, structure, and tectonic evolution of the complex junction area between the NW-striking Coast Ranges and EW-striking western Transverse Ranges. The 1:24,000-scale geologic map of the San Guillermo Mountain quadrangle is one of six contiguous 7 1/2' quadrangle geologic maps in the eastern part of the Cuyama map area being compiled for a more detailed portrayal and reevaluation of geologic structures and rock units shown on previous geologic maps of the area (e.g., Dibblee, 1979). The following observations and interpretations are based on the new San Guillermo Mountain geologic compilation: (1) The new geologic mapping in the northern part of the San Guillermo Mountain quadrangle allows for reinterpretation of fault architecture that bears on potential seismic hazards of the region. Previous mapping had depicted the eastern Big Pine fault (BPF) as a northeast-striking, sinistral strike-slip fault that extends for 30 km northeast of the Cuyama River to its intersection with the San Andreas fault (SAF). In contrast the new mapping indicates that the eastern BPF is a thrust fault that curves from a northeast strike to an east strike, where it is continuous with the San Guillermo thrust fault, and dies out further east about 15 km south of the SAF. This redefined segment of the BPF is a south-dipping, north-directed thrust, with dominantly dip slip components (rakes > 60 deg.), that places Middle Eocene marine rocks (Juncal and Matilija Formations) over Miocene through Pliocene(?) nonmarine rocks (Caliente, Quatal, and Morales Formations). Although a broad northeast-striking fault zone, exhibiting predominantly sinistral components of slip (rakes structures. These revised fault interpretations bring into question earlier estimates of net sinistral strike

  1. UAVSAR observations of triggered slip on the Imperial, Superstition Hills, and East Elmore Ranch Faults associated with the 2010 M 7.2 El Mayor-Cucapah earthquake (United States)

    Donnellan, Andrea; Parker, Jay; Hensley, Scott; Pierce, Marlon; Wang, Jun; Rundle, John


    4 April 2010 M 7.2 El Mayor-Cucapah earthquake that occurred in Baja California, Mexico and terminated near the U.S. Mexican border caused slip on the Imperial, Superstition Hills, and East Elmore Ranch Faults. The pattern of slip was observed using radar interferometry from NASA's Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) instrument collected on 20-21 October 2009 and 12-13 April 2010. Right-lateral slip of 36 ± 9 and 14 ± 2 mm occurred on the Imperial and Superstition Hills Faults, respectively. Left-lateral slip of 9 ± 2 mm occurred on the East Elmore Ranch Fault. The widths of the zones of displacement increase northward suggesting successively more buried fault motion to the north. The observations show a decreasing pattern of slip northward on a series of faults in the Salton Trough stepping between the El Mayor-Cucapah rupture and San Andreas Fault. Most of the motion occurred at the time of the M 7.2 earthquake and the UAVSAR observations are consistent with field, creepmeter, GPS, and Envisat observations. An additional 28 ± 1 mm of slip at the southern end of the Imperial Fault over a <1 km wide zone was observed over a 1 day span a week after the earthquake suggesting that the fault continued to slip at depth following the mainshock. The total moment release on the three faults is 2.3 × 1023-1.2 × 1024 dyne cm equivalent to a moment magnitude release of 4.9-5.3, assuming shallow slip depths ranging from 1 to 5 km.

  2. On the innovative genius of Andreas Vesalius

    NARCIS (Netherlands)

    Brinkman, R.J.C.


    Andreas Vesalius (1515 - 1564) is generally considered to be the founding father of modern human anatomy. To commemorate his 500th birthday, some of the most striking anatomical and physiological aspects of Vesalius’ major work De Humani Corporis Fabrica Libri Septem (De Fabrica) are presented and

  3. A Response to Andrea R. Halpern's Commentary

    Directory of Open Access Journals (Sweden)

    Freya Bailes


    Full Text Available The author responds to points raised in Andrea Halpern’s commentary, which appeared in Vol. 2, No. 1 of Empirical Musicology Review. Discussion focuses on the apparent contradiction between self-reports of veridical mental imagery of musical timbre, and cognitive constraints on temporal memory for multidimensional sound.

  4. Andrea Dworkin on Pornography: Exposing "Male Truth." (United States)

    VerLinden, Jay G.

    Radical feminist Andrea Dworkin has been instrumental in efforts to curtail pornography by defining it as a violation of women's civil rights and allowing individual women to sue the distributors for damages. Dworkin's position derives from the tension between "what should be" and "what is." Her conception of the difference…

  5. Investigations into the Fish Lake Valley Fault Zone (FLVFZ) and its interactions with normal faulting within Eureka and Deep Springs Valleys (United States)

    Lawson, M. J.; Rhodes, E.; Yin, A.


    In most textbooks, the San Andreas Fault is stated to be the plate boundary between the North American and the Pacific plates, as plate tectonics assumes that boundaries are essentially discrete. In the Western United States this is not the case, as up to 25% of relative plate motion is accommodated on other structures within the Walker Lane Shear Zone (WLSZ) in a diffuse 100 km margin (Faulds et al., 2005; Oldow et al., 2001). Fish Lake Valley Fault Zone (FLVFZ), situated at the northern border of Death Valley National Park, is the northern continuation of the Furnace Creek Fault Zone (FCFZ), and is an important transfer structure within the Walker Lane Shear Zone. Though the FLVFZ has a long term rate (since 10 Ma) of 5 mm/yr (Reheis and Sawyer, 1997), it has a highly variable slip rate. In the middle Pleistocene, the rate has a maximum of up to 11 mm/yr which would accommodate nearly the entirety of slip within the Walker Lane, and yet this rate decreases significantly ( 2.5 to 3 mm/yr) by the late Pleistocene due to unknown causes (Frankel et al. 2007). This variation in slip rate has been proposed by previous workers to be due to strain transience, an increase in the overall strain rate, or due to other unknown structures (Lee et al., 2009). Currently, we are investigating the cause of this variation, and the possibility of the transfer of slip to faults south of the FLVFZ on oblique normal faults within Eureka and Deep Springs Valleys. Preliminary data will be shown utilizing scarp transects, geomorphic scarp modeling, and Optically Stimulated Luminescence (OSL) dating techniques.

  6. Testing Pixel Translation Digital Elevation Models to Reconstruct Slip Histories: An Example from the Agua Blanca Fault, Baja California, Mexico (United States)

    Wilson, J.; Wetmore, P. H.; Malservisi, R.; Ferwerda, B. P.; Teran, O.


    We use recently collected slip vector and total offset data from the Agua Blanca fault (ABF) to constrain a pixel translation digital elevation model (DEM) to reconstruct the slip history of this fault. This model was constructed using a Perl script that reads a DEM file (Easting, Northing, Elevation) and a configuration file with coordinates that define the boundary of each fault segment. A pixel translation vector is defined as a magnitude of lateral offset in an azimuthal direction. The program translates pixels north of the fault and prints their pre-faulting position to a new DEM file that can be gridded and displayed. This analysis, where multiple DEMs are created with different translation vectors, allows us to identify areas of transtension or transpression while seeing the topographic expression in these areas. The benefit of this technique, in contrast to a simple block model, is that the DEM gives us a valuable graphic which can be used to pose new research questions. We have found that many topographic features correlate across the fault, i.e. valleys and ridges, which likely have implications for the age of the ABF, long term landscape evolution rates, and potentially provide conformation for total slip assessments The ABF of northern Baja California, Mexico is an active, dextral strike slip fault that transfers Pacific-North American plate boundary strain out of the Gulf of California and around the "Big Bend" of the San Andreas Fault. Total displacement on the ABF in the central and eastern parts of the fault is 10 +/- 2 km based on offset Early-Cretaceous features such as terrane boundaries and intrusive bodies (plutons and dike swarms). Where the fault bifurcates to the west, the northern strand (northern Agua Blanca fault or NABF) is constrained to 7 +/- 1 km. We have not yet identified piercing points on the southern strand, the Santo Tomas fault (STF), but displacement is inferred to be ~4 km assuming that the sum of slip on the NABF and STF is

  7. Geology, geochronology, and paleogeography of the southern Sonoma volcanic field and adjacent areas, northern San Francisco Bay region, California (United States)

    Wagner, David L.; Saucedo, George J.; Clahan, Kevin B.; Fleck, Robert J.; Langenheim, Victoria E.; McLaughlin, Robert J.; Sarna-Wojcicki, Andrei M.; Allen, James R.; Deino, Alan L.


    Recent geologic mapping in the northern San Francisco Bay region (California, USA) supported by radiometric dating and tephrochronologic correlations, provides insights into the framework geology, stratigraphy, tectonic evolution, and geologic history of this part of the San Andreas transform plate boundary. There are 25 new and existing radiometric dates that define three temporally distinct volcanic packages along the north margin of San Pablo Bay, i.e., the Burdell Mountain Volcanics (11.1 Ma), the Tolay Volcanics (ca. 10–8 Ma), and the Sonoma Volcanics (ca. 8–2.5 Ma). The Burdell Mountain and the Tolay Volcanics are allochthonous, having been displaced from the Quien Sabe Volcanics and the Berkeley Hills Volcanics, respectively. Two samples from a core of the Tolay Volcanics taken from the Murphy #1 well in the Petaluma oilfield yielded ages of 8.99 ± 0.06 and 9.13 ± 0.06 Ma, demonstrating that volcanic rocks exposed along Tolay Creek near Sears Point previously thought to be a separate unit, the Donnell Ranch volcanics, are part of the Tolay Volcanics. Other new dates reported herein show that volcanic rocks in the Meacham Hill area and extending southwest to the Burdell Mountain fault are also part of the Tolay Volcanics. In the Sonoma volcanic field, strongly bimodal volcanic sequences are intercalated with sediments. In the Mayacmas Mountains a belt of eruptive centers youngs to the north. The youngest of these volcanic centers at Sugarloaf Ridge, which lithologically, chemically, and temporally matches the Napa Valley eruptive center, was apparently displaced 30 km to the northwest by movement along the Carneros and West Napa faults. The older parts of the Sonoma Volcanics have been displaced at least 28 km along the Rodgers Creek fault since ca. 7 Ma. The Petaluma Formation also youngs to the north along the Rodgers Creek–Hayward fault and the Bennett Valley fault. The Petaluma basin formed as part of the Contra Costa basin in the Late Miocene and

  8. Fault and anthropogenic processes in central California constrained by satellite and airborne InSAR and in-situ observations (United States)

    Liu, Zhen; Lundgren, Paul


    The San Andreas Fault (SAF) system is the primary plate boundary in California, with the central SAF (CSAF) lying adjacent to the San Joaquin Valley (SJV), a vast structural trough that accounts for about one-sixth of the United Sates' irrigated land and one-fifth of its extracted groundwater. The CSAF displays a range of fault slip behavior with creeping in its central segment that decreases towards its northwest and southeast ends, where the fault transitions to being fully locked. At least six Mw ~6.0 events since 1857 have occurred near the Parkfield transition, most recently in 2004. Large earthquakes also occurred on secondary faults parallel to the SAF, the result of distributed deformation across the plate boundary zone. Recent studies have revealed the complex interaction between anthropogenic related groundwater depletion and the seismic activity on adjacent faults through stress interaction. Despite recent progress, many questions regarding fault and anthropogenic processes in the region still remain. For example, how is the relative plate motion accommodated between the CSAF and off-fault deformation? What is the distribution of fault creep and slip deficit at shallow depths? What are the spatiotemporal variations of fault slip? What are the spatiotemporal characteristics of anthropogenic and lithospheric processes and how do they interact with each other? To address these, we combine satellite InSAR and NASA airborne UAVSAR data to image on and off-fault deformation. The UAVSAR data cover fault perpendicular swaths imaged from opposing look directions and fault parallel swaths since 2009. The much finer spatial resolution and optimized viewing geometry provide important constraints on near fault deformation and fault slip at very shallow depth. We performed a synoptic InSAR time series analysis using ERS-1/2, Envisat, ALOS and UAVSAR interferograms. The combined C-band ERS-1/2 and Envisat data provide a long time interval of SAR data over the region

  9. Quantification of Fault-Zone Plasticity Effects with Spontaneous Rupture Simulations (United States)

    Roten, D.; Olsen, K. B.; Day, S. M.; Cui, Y.


    Previous studies have shown that plastic yielding in crustal rocks in the fault zone may impose a physical limit to extreme ground motions. We explore the effects of fault-zone non-linearity on peak ground velocities (PGVs) by simulating a suite of surface-rupturing strike-slip earthquakes in a medium governed by Drucker-Prager plasticity using the AWP-ODC finite-difference code. Our simulations cover magnitudes ranging from 6.5 to 8.0, three different rock strength models, and average stress drops of 3.5 and 7.0 MPa, with a maximum frequency of 1 Hz and a minimum shear-wave velocity of 500 m/s. Friction angles and cohesions in our rock models are based on strength criteria which are frequently used for fractured rock masses in civil and mining engineering. For an average stress drop of 3.5 MPa, plastic yielding reduces near-fault PGVs by 15-30% in pre-fractured, low strength rock, but less than 1% in massive, high-quality rock. These reductions are almost insensitive to magnitude. If the stress drop is doubled, plasticity reduces near-fault PGVs by 38-45% and 5-15% in rocks of low and high strength, respectively. Because non-linearity reduces slip rates and static slip near the surface, plasticity acts in addition to, and may partially be emulated by, a shallow velocity-strengthening layer. The effects of plasticity are exacerbated if a fault damage zone with reduced shear-wave velocities and reduced rock strength is present. In the linear case, fault-zone trapped waves result in higher near-surface peak slip rates and ground velocities compared to simulations without a low-velocity zone. These amplifications are balanced out by fault-zone plasticity if rocks in the damage zone exhibit low-to-moderate strength throughout the depth extent of the low-velocity zone (˜5 km). We also perform dynamic non-linear simulations of a high stress drop (8 MPa) M 7.8 earthquake rupturing the southern San Andreas fault along 250 km from Indio to Lake Hughes. Non-linearity in the

  10. Absolute age determination of quaternary faults

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Chang Sik; Lee, Seok Hoon; Choi, Man Sik [Korea Basic Science Institute, Seoul (Korea, Republic of)] (and others)


    To constrain the age of neotectonic fault movement, Rb-Sr, K-Ar, U-series disequilibrium, C-14 and Be-10 methods were applied to the fault gouges, fracture infillings and sediments from the Malbang, Ipsil, Wonwonsa faults faults in the Ulsan fault zone, Yangsan fault in the Yeongdeog area and southeastern coastal area. Rb-Sr and K-Ar data imply that the fault movement of the Ulan fault zone initiated at around 30 Ma and preliminary dating result for the Yang san fault is around 70 Ma in the Yeongdeog area. K-Ar and U-series disequilibrium dating results for fracture infillings in the Ipsil fault are consistent with reported ESR ages. Radiocarbon ages of quaternary sediments from the Jeongjari area are discordant with stratigraphic sequence. Carbon isotope data indicate a difference of sedimentry environment for those samples. Be-10 dating results for the Suryum fault area are consistent with reported OSL results.

  11. Quantification of Ground Motion Reductions by Fault Zone Plasticity with 3D Spontaneous Rupture Simulations (United States)

    Roten, D.; Olsen, K. B.; Cui, Y.; Day, S. M.


    We explore the effects of fault zone nonlinearity on peak ground velocities (PGVs) by simulating a suite of surface rupturing earthquakes in a visco-plastic medium. Our simulations, performed with the AWP-ODC 3D finite difference code, cover magnitudes from 6.5 to 8.0, with several realizations of the stochastic stress drop for a given magnitude. We test three different models of rock strength, with friction angles and cohesions based on criteria which are frequently applied to fractured rock masses in civil engineering and mining. We use a minimum shear-wave velocity of 500 m/s and a maximum frequency of 1 Hz. In rupture scenarios with average stress drop (~3.5 MPa), plastic yielding reduces near-fault PGVs by 15 to 30% in pre-fractured, low-strength rock, but less than 1% in massive, high quality rock. These reductions are almost insensitive to the scenario earthquake magnitude. In the case of high stress drop (~7 MPa), however, plasticity reduces near-fault PGVs by 38 to 45% in rocks of low strength and by 5 to 15% in rocks of high strength. Because plasticity reduces slip rates and static slip near the surface, these effects can partially be captured by defining a shallow velocity-strengthening layer. We also perform a dynamic nonlinear simulation of a high stress drop M 7.8 earthquake rupturing the southern San Andreas fault along 250 km from Indio to Lake Hughes. With respect to the viscoelastic solution (a), nonlinearity in the fault damage zone and in near-surface deposits would reduce long-period (> 1 s) peak ground velocities in the Los Angeles basin by 15-50% (b), depending on the strength of crustal rocks and shallow sediments. These simulation results suggest that nonlinear effects may be relevant even at long periods, especially for earthquakes with high stress drop.

  12. "Ghost transients" in the southern California GPS velocity field: An investigation using finite-fault earthquake cycle models (United States)

    Hearn, E. H.; Pollitz, F. F.; Thatcher, W. R.; Onishi, C. T.


    Elastic block models are generally used to infer slip rates on fault segments in tectonically complex areas, such as southern California (e.g. McCaffrey, 2005; Meade et al., 2005). These models implicitly assume steady-state deformation. However, owing to viscoelastic effects of past large earthquakes, deformation rates and patterns around major faults are expected to vary with time. Where viscoelasticity has been incorporated into block models, differences in inferred slip rates have resulted (Johnson et al., 2007). Here, we investigate the extent to which viscoelastic velocity perturbations (or "ghost transients") from individual earthquakes can affect elastic block model-based inferences of fault slip rates from GPS velocity fields. We focus on the southern California GPS velocity field, exploring the effects of known, large earthquakes for end-member rheological structures. For selected faults, an idealized earthquake history is constructed, consisting of a sequence of periodic, identical repeating slip events. For each earthquake, we first calculate average velocities and time-dependent perturbations relative to this average at all GPS sites in the neighborhood of an earthquake. (We deal with perturbations because to recover the velocities, we would have to compute and sum cycle-average velocities and perturbations for all fault segments in the region.) Next, we invert two GPS velocity fields for slip rates using a block modeling approach: one field that has been corrected for the perturbation, and one which has not, and we compare the resulting slip rates. For now, the viscoelastic models are simple (layers with linear rheologies), and locking depth is fixed in the block models. We find that if asthenosphere viscosities are low enough (3 x 10**18 Pa-s) the current GPS velocity field is significantly perturbed by the 1857 M 7.9 San Andreas Fault (SAF) earthquake sequence; that is, current strain rates around the SAF are lower than their average values

  13. Rhazes in the Renaissance of Andreas Vesalius


    Compier, Abdul Haq


    Andreas Vesalius' (1514–64) first publication was a Paraphrasis of the ninth book of the Liber ad Almansorem, written by the Arab–Persian physician and alchemist Rhazes (854–925). The role of Rhazes in Vesalius' oeuvre has thus far been much disregarded. The different ways Rhazes recurs reveal an intellectual evolution in Vesalius' work. In the Paraphrasis, Vesalius subjects Rhazes to the authority of Galen in the context of the early sixteenth-century humanist campaign for the substitution o...

  14. Andreas Vesalius--the reformer of anatomy. (United States)

    Holomanova, A; Ivanova, A; Brucknerova, I; Benuska, J


    This paper deals with two main topics. The first part provides data on the life of Andreas Vesalius, a scholar and anatomist of the 16th century, and describes the environment in which he lived and worked. It highlights his personality of a great doctor and teacher and points out the importance of his scientific methods and techniques as opposed to speculative methods that were prevalent in the scientific research in those days. The second part of the paper is devoted to the characteristics and description of his famous and, given the times he lived in, grand work called "De Humani Corporis Fabrica", which opened a new epoch in the history of anatomy. Andreas Vesalius is considered to be the founder of the science of anatomy which is based on observation and experience gained by using scalpel on dead bodies of humans. This is how he proved the then valid statements wrong. This complex view of life and work of Andreas Vesalius is aimed at highlighting the milestone which he represents in this traditional science of anatomy that has been conscientiously developed since the Classical times. (Fig. 4, Ref. 6.)

  15. Measurement of Creep on the Calaveras Fault at Coyote Dam using Terrestrial Radar Interferometry (TRI). (United States)

    Baker, B.; Cassotto, R.; Fahnestock, M. A.; Werner, C. L.; Boettcher, M. S.


    The Calaveras fault in central California is part of the San Andreas fault system. Coyote Dam, an earthen dam that straddles the fault ~13km northeast of Gilroy, experiences creep style deformation that ranges from 10 to 15 mm/yr. Uncertainty in the location of the fault, coupled with the historic rate of deformation, affect the dam's safety factor. Assessing the impact of fault creep on the dam's stability is paramount to its safety evaluation, but is difficult to resolve due to limited spatial and temporal sampling of conventional methods. Terrestrial radar interferometry (TRI), like satellite-based observations, produces high spatial resolution maps of ground deformation. Unlike space-based sensors, TRI can be readily deployed and the observation geometry selected to get the maximum line of sight (LOS) signal. TRI also benefits from high temporal sampling which can be used to reduce errors related to atmospheric phase delays and high temporal sampling also facilitates tracking rapidly moving features such as landslides and glaciers. GAMMA Portable Radar Interferometer (GPRI) measurements of Coyote Dam rock faces were made from concrete piers built upstream and downstream of the dam. The GPRI operates at a radar frequency of 17.2 GHz with a spatial resolution at the dam of approximately 0.9 m x 2.0 m. Changes in LOS path length smaller than 0.1mm can be measured. Data were acquired approximately every 2 to 3 weeks over a 7-month period to map the fault trace through the dam faces. Our study exploits the dense record of observations obtained, and the relatively short distance of the radar to the dam to minimize atmospheric affects. We investigate how the deformation evolves in time and the orientation of fault through the dam, including the strike and dip as measured along the dam surface. Our results show rates consistent with GPS data and regional satellite observations, but produce a much more detailed map of the fault on the dam than possible with GPS or

  16. Deep-seated landslides and seismic triggering along major transcurrent faults in central Asia and California. (United States)

    Rust, Derek; Korjenkov, Andrey; Bobrovskii, Alexander; Mamyrov, Ernes


    The Tien Shan mountains of central Asia, the northernmost expression of India-Eurasia collision, are characterised by active deformation (GPS measured contraction rates of ~20 mm a-1), rapid uplift and steep slopes prone to landsliding. In addition to seismogenic structures associated with contraction, the mountain belt is bisected by the Talas-Fergana fault, a poorly-known, historically aseismic, 700-km-long dextral strike-slip structure displaying active faulting and landslide features similar to those along the San Andreas fault in the Transverse Ranges of southern California. In both cases uplift along fault traces making up the fault zones has produced a deep central trough occupied by landslide and reworked landslide deposits, bordered by mountain ridges dominated by high to medium grade metamorphic bedrock and acting as landslide source areas. Moreover, palaeoseismic evidence suggests both fault zones may be regarded as seismic gaps characterised by relatively infrequent large-magnitude earthquakes. The numerous deep-seated landslides along both fault zones record a long history of landsliding based on: 1) radiocarbon dating; 2) sequences of lacustrine deposits containing apparent seismites and formed in landslide-dammed lakes now breached and drained; 3) recorded offsets and entrenchment of drainage features and deposits, associated with a characteristic cycle of fluvial reworking of landslide masses; 4) perched gravels preserved high on central trough walls and interpreted as related to reworking of landslide deposits; 5) degree of erosional and depositional degradation, including a time-series of landslide mass - lacustrine deposit assemblages. Together, these features suggest a landslide history characterised by large-volume failures, a pattern thought to mirror that of seismic strain release along these apparently locked fault systems. It seems likely that deep-seated landslides are effectively only triggered by major faulting events in these settings

  17. SEISMOLOGY: Watching the Hayward Fault. (United States)

    Simpson, R W


    The Hayward fault, located on the east side of the San Francisco Bay, represents a natural laboratory for seismologists, because it does not sleep silently between major earthquakes. In his Perspective, Simpson discusses the study by Bürgmann et al., who have used powerful new techniques to study the fault. The results indicate that major earthquakes cannot originate in the northern part of the fault. However, surface-rupturing earthquakes have occurred in the area, suggesting that they originated to the north or south of the segment studied by Bürgmann et al. Fundamental questions remain regarding the mechanism by which plate tectonic stresses are transferred to the Hayward fault.

  18. Continuity of the West Napa–Franklin fault zone inferred from guided waves generated by earthquakes following the 24 August 2014 Mw 6.0 South Napa earthquake (United States)

    Catchings, Rufus D.; Goldman, Mark R.; Li, Yong-Gang; Chan, Joanne


    We measure peak ground velocities from fault‐zone guided waves (FZGWs), generated by on‐fault earthquakes associated with the 24 August 2014 Mw 6.0 South Napa earthquake. The data were recorded on three arrays deployed across north and south of the 2014 surface rupture. The observed FZGWs indicate that the West Napa fault zone (WNFZ) and the Franklin fault (FF) are continuous in the subsurface for at least 75 km. Previously published potential‐field data indicate that the WNFZ extends northward to the Maacama fault (MF), and previous geologic mapping indicates that the FF extends southward to the Calaveras fault (CF); this suggests a total length of at least 110 km for the WNFZ–FF. Because the WNFZ–FF appears contiguous with the MF and CF, these faults apparently form a continuous Calaveras–Franklin–WNFZ–Maacama (CFWM) fault that is second only in length (∼300  km) to the San Andreas fault in the San Francisco Bay area. The long distances over which we observe FZGWs, coupled with their high amplitudes (2–10 times the S waves) suggest that strong shaking from large earthquakes on any part of the CFWM fault may cause far‐field amplified fault‐zone shaking. We interpret guided waves and seismicity cross sections to indicate multiple upper crustal splays of the WNFZ–FF, including a northward extension of the Southhampton fault, which may cause strong shaking in the Napa Valley and the Vallejo area. Based on travel times from each earthquake to each recording array, we estimate average P‐, S‐, and guided‐wave velocities within the WNFZ–FF (4.8–5.7, 2.2–3.2, and 1.1–2.8  km/s, respectively), with FZGW velocities ranging from 58% to 93% of the average S‐wave velocities.

  19. Liquefaction Hazard Maps for Three Earthquake Scenarios for the Communities of San Jose, Campbell, Cupertino, Los Altos, Los Gatos, Milpitas, Mountain View, Palo Alto, Santa Clara, Saratoga, and Sunnyvale, Northern Santa Clara County, California (United States)

    Holzer, Thomas L.; Noce, Thomas E.; Bennett, Michael J.


    Maps showing the probability of surface manifestations of liquefaction in the northern Santa Clara Valley were prepared with liquefaction probability curves. The area includes the communities of San Jose, Campbell, Cupertino, Los Altos, Los Gatos Milpitas, Mountain View, Palo Alto, Santa Clara, Saratoga, and Sunnyvale. The probability curves were based on complementary cumulative frequency distributions of the liquefaction potential index (LPI) for surficial geologic units in the study area. LPI values were computed with extensive cone penetration test soundings. Maps were developed for three earthquake scenarios, an M7.8 on the San Andreas Fault comparable to the 1906 event, an M6.7 on the Hayward Fault comparable to the 1868 event, and an M6.9 on the Calaveras Fault. Ground motions were estimated with the Boore and Atkinson (2008) attenuation relation. Liquefaction is predicted for all three events in young Holocene levee deposits along the major creeks. Liquefaction probabilities are highest for the M7.8 earthquake, ranging from 0.33 to 0.37 if a 1.5-m deep water table is assumed, and 0.10 to 0.14 if a 5-m deep water table is assumed. Liquefaction probabilities of the other surficial geologic units are less than 0.05. Probabilities for the scenario earthquakes are generally consistent with observations during historical earthquakes.

  20. Dynamic rupture simulations on complex fault zone structures with off-fault plasticity using the ADER-DG method (United States)

    Wollherr, Stephanie; Gabriel, Alice-Agnes; Igel, Heiner


    zones or branched faults. Studying the interplay of stress conditions and angle dependence of neighbouring branches including inelastic material behaviour and its effects on rupture jumps and seismic activation helps to advance our understanding of earthquake source processes. An application is the simulation of a real large-scale subduction zone scenario including plasticity to validate the coupling of our dynamic rupture calculations to a tsunami model in the framework of the ASCETE project ( Andrews, D. J. (2005): Rupture dynamics with energy loss outside the slip zone, J. Geophys. Res., 110, B01307. Heinecke, A. (2014), A. Breuer, S. Rettenberger, M. Bader, A.-A. Gabriel, C. Pelties, A. Bode, W. Barth, K. Vaidyanathan, M. Smelyanskiy and P. Dubey: Petascale High Order Dynamic Rupture Earthquake Simulations on Heterogeneous Supercomputers. In Supercomputing 2014, The International Conference for High Performance Computing, Networking, Storage and Analysis. IEEE, New Orleans, LA, USA, November 2014. Roten, D. (2014), K. B. Olsen, S.M. Day, Y. Cui, and D. Fäh: Expected seismic shaking in Los Angeles reduced by San Andreas fault zone plasticity, Geophys. Res. Lett., 41, 2769-2777.

  1. Bounding the moment deficit rate on crustal faults using geodetic data: Methods (United States)

    Maurer, Jeremy; Segall, Paul; Bradley, Andrew M.


    The geodetically derived interseismic moment deficit rate (MDR) provides a first-order constraint on earthquake potential and can play an important role in seismic hazard assessment, but quantifying uncertainty in MDR is a challenging problem that has not been fully addressed. We establish criteria for reliable MDR estimators, evaluate existing methods for determining the probability density of MDR, and propose and evaluate new methods. Geodetic measurements moderately far from the fault provide tighter constraints on MDR than those nearby. Previously used methods can fail catastrophically under predictable circumstances. The bootstrap method works well with strong data constraints on MDR, but can be strongly biased when network geometry is poor. We propose two new methods: the Constrained Optimization Bounding Estimator (COBE) assumes uniform priors on slip rate (from geologic information) and MDR, and can be shown through synthetic tests to be a useful, albeit conservative estimator; the Constrained Optimization Bounding Linear Estimator (COBLE) is the corresponding linear estimator with Gaussian priors rather than point-wise bounds on slip rates. COBE matches COBLE with strong data constraints on MDR. We compare results from COBE and COBLE to previously published results for the interseismic MDR at Parkfield, on the San Andreas Fault, and find similar results; thus, the apparent discrepancy between MDR and the total moment release (seismic and afterslip) in the 2004 Parkfield earthquake remains.

  2. Homage to genial anatomist - Andreas Vesalius. (United States)

    Brucknerova, Ingrid; Holomanova, Anna


    The paper highlights the personality of the founder of modern anatomy, who was able to use his knowledge and skills to change the view on the construction of the human body extending over centuries. He introduced a new scientific approach and highlighted the importance of autopsies for understanding of human body which carefully demonstrated and documented. De humani corporis fabrica - the spectacular work, in which he summarized results of his theoretical and practical findings, has opened a new path for the study of anatomy. Andreas Vesalius became a pioneer in the history of medical education. In 2014 will pass 500 years since his birth.

  3. The last months of Andreas Vesalius. (United States)

    Biesbrouck, Maurits; Steeno, Omer


    A good deal has already been written about the last months of Andreas Vesalius' life. Most of it has been fairly speculative, because the necessary primary sources have been lacking. Much of what was supposedly known for sure seemed bizarre, and various writers even frankly characterised their own accounts as 'legend'. It is only since the discovery of several letters in the archives of Simancas by Josh Baron in 1962 that various points have become somewhat clearer. Baron presented these letters at the 19th International Congress on the History of Medicine in Basel in September 1964.

  4. Rapid mapping of ultrafine fault zone topography with structure from motion (United States)

    Johnson, Kendra; Nissen, Edwin; Saripalli, Srikanth; Arrowsmith, J. Ramón; McGarey, Patrick; Scharer, Katherine M.; Williams, Patrick; Blisniuk, Kimberly


    Structure from Motion (SfM) generates high-resolution topography and coregistered texture (color) from an unstructured set of overlapping photographs taken from varying viewpoints, overcoming many of the cost, time, and logistical limitations of Light Detection and Ranging (LiDAR) and other topographic surveying methods. This paper provides the first investigation of SfM as a tool for mapping fault zone topography in areas of sparse or low-lying vegetation. First, we present a simple, affordable SfM workflow, based on an unmanned helium balloon or motorized glider, an inexpensive camera, and semiautomated software. Second, we illustrate the system at two sites on southern California faults covered by existing airborne or terrestrial LiDAR, enabling a comparative assessment of SfM topography resolution and precision. At the first site, an ∼0.1 km2 alluvial fan on the San Andreas fault, a colored point cloud of density mostly >700 points/m2 and a 3 cm digital elevation model (DEM) and orthophoto were produced from 233 photos collected ∼50 m above ground level. When a few global positioning system ground control points are incorporated, closest point vertical distances to the much sparser (∼4 points/m2) airborne LiDAR point cloud are mostly 530 points/m2 and a 2 cm DEM and orthophoto were produced from 450 photos taken from ∼60 m above ground level. Closest point vertical distances to existing terrestrial LiDAR data of comparable density are mostly <6 cm. Each SfM survey took ∼2 h to complete and several hours to generate the scene topography and texture. SfM greatly facilitates the imaging of subtle geomorphic offsets related to past earthquakes as well as rapid response mapping or long-term monitoring of faulted landscapes.

  5. Gouge-zone or solid-rock: An experimental view on fault frictional behavior (United States)

    Reches, Z.


    Natural faults always include zone(s) of breccia, gouge or cataclasite that localize the slip. In contrast, many rock mechanics experiments are conducted on experimental faults made of rough, solid blocks without fault-rock zones. We experimentally compare the frictional strength of solid experimental faults with fault-zones made of granular material in high-velocity/long-distance runs. The frictional evolution of solid and granular dolomite fault was tested in a rotary apparatus at slip velocity up to 1 m/s and normal stress up to 7 MPa. The granular samples were composed of the 125-250 microns fraction of the crushed dolomite. They were sheared in a confined, rotary cell with continuous monitoring of CO2 and H2O and mechanical data. The tests showed that the granular samples required longer slip-distances and higher velocities to evolve to a frictional strength similar to the solid samples. Yet, both sample types display similar evolution trends, including slip-weakening at velocities above ~0.05 m/s, and drastic velocity-weakening as slip velocity approached 1 m/s. At velocity above 0.3 m/s, a shining principal-slip-zone developed spontaneously with identical microstructure in both solid and granular sample: thickness friction evolution of granular granite from the San-Andreas fault-zone at Tejon-Pass, CA. These samples remained strong, μ =0.8-0.9, at velocities up to 0.8 m/s and slip-distances up to 3 m, in contrast to known frictional evolution of solid faults made of granite and tonalite. We envision that at the present slip-velocity/normal-stress, the dolomite samples reached a stage of thermally activated phase-transition and associated weakening, whereas the granitic samples were below such transition. Fig. 1. Evolotion of slip-velocity, friction, temperature and CO2 emission in run 3165 with granular Kasota dolomite. Normal stress is 3.3 MPa. The time delay of CO2 data reflect gas flow from shear chamber to gas analyzer.

  6. Ugala juurutab fantasy't / Andreas W ; interv. Margus Kasterpalu

    Index Scriptorium Estoniae

    Andreas W, pseud., 1969-


    "Meremaa võlur. Päeva kaldad", näidend Ursula K Le Guini "Meremaa võluri" teemadel,kirjutanud Andreas W ja lavastanud Andres Noormets, kunstnik Silver Vahtre, valguskunstnik Airi Eras, helikujundaja ja videograafik Andreas W. Esietendus Ugalas 29. apr.

  7. Detailed Northern Anatolian Fault Zone crustal structure from receiver functions (United States)

    Cornwell, D. G.; Kahraman, M.; Thompson, D. A.; Houseman, G. A.; Rost, S.; Turkelli, N.; Teoman, U.; Altuncu Poyraz, S.; Gülen, L.; Utkucu, M.


    We present high resolution images derived from receiver functions of the continental crust in Northern Turkey that is dissected by two fault strands of the Northern Anatolian Fault Zone (NAFZ). The NAFZ is a major continental strike-slip fault system that is comparable in length and slip rate to the San Andreas Fault Zone. Recent large earthquakes occurred towards the western end of the NAFZ in 1999 at Izmit (M7.5) and Düzce (M7.2). As part of the multi-disciplinary Faultlab project, we aim to develop a model of NAFZ crustal structure and locate deformation by constraining variations in seismic properties and anisotropy in the upper and lower crust. The crustal model will be an input to test deformation scenarios in order to match geodetic observations from different phases of the earthquake loading cycle. We calculated receiver functions from teleseismic earthquakes recorded by a rectangular seismometer array spanning the NAFZ with 66 stations at a nominal inter-station spacing of 7 km and 7 additional stations further afield. This Dense Array for North Anatolia (DANA) was deployed from May 2012 until September 2013 and we selected large events (Mw>5.5) from the high quality seismological dataset to analyze further. Receiver functions were calculated for different frequency bands then collected into regional stacks before being inverted for crustal S-wave velocity structure beneath the entire DANA array footprint. In addition, we applied common conversion point (CCP) migration using a regional velocity model to construct a migrated 3D volume of P-to-S converted and multiple energy in order to identify the major crustal features and layer boundaries. We also performed the CCP migration with transverse receiver functions in order to identify regions of anisotropy within the crustal layers. Our preliminary results show a heterogeneous crust above a flat Moho that is typically at a depth of 33 km. We do not observe a prominent step in the Moho beneath the surface

  8. Thrust Faulting, Vp, Vs, Vp/Vs and Poisson's Ratios Beneath the Santa Clara Valley, California as Determined from the Santa Clara Seismic Investigation (SCSI) (United States)

    Catchings, R. D.; Goldman, M. R.; Kiger, L.; Saulter, D.; Wentworth, C.


    In December 2000, we conducted an ~20-km-long, southwest-northeast-trending seismic reflection and refraction seismic imaging survey extending from the central Santa Cruz Mountains to the central Santa Clara Valley. The Santa Clara Seismic investigation (SCSI) originated within 0.5 km of the surface trace of the San Andreas fault zone and terminated in downtown San Jose. Between its origin and terminus, the profile crossed the Cupertino Basin and numerous mapped faults, including the Monte Vista thrust fault. Seismic sources were generated by 11 explosions ranging in size from about 12 to 23 kg (25 to 50 lbs.) and were spaced approximately 1 km apart in the central part of the profile. The seismic data were recorded with approximately 400 PASSCAL Texan seismographs, spaced approximately 50 m apart. We inverted first-arrival refractions to determine the P- and S-wave velocity structure of the upper 3.5 km of the crust, and we stacked the seismic reflection data to develop reflection images the upper 10 km of the crust. Our data indicate that P-wave velocities range from about 1.3 km/s near the surface to about 6.0 km/s at varying depths along the profile. Measured S-wave velocities range from about 0.6 km/s near the surface to about 2.6 km/s at varying depths along the profile. Vp/Vs and Poisson's ratios vary from about 1.57 to about 2.10 and from 0.16 to about 0.37, respectively. All velocities and ratios vary laterally and vertically along the profile, but there is an appreciable difference on either side of the Monte Vista fault. Beneath the central Cupertino Basin, the velocity data suggest that sediments (3 km/s) are about 1.2 km deep, thinning to about 600 m deep beneath downtown San Jose and to 0 km deep in the Santa Cruz Mountains. These data show that the Santa Clara Valley and Cupertino Basin sediments are shallower beneath our profile than previously believed. The velocity image also shows a clear low-velocity zone that is most prominent beneath the town

  9. Strain accumulation on faults beneath Los Angeles: a geodesy-based picture accounting for the effects of sedimentary basins and anthropogenic surface deformation (United States)

    Rollins, C.; Argus, D. F.; Landry, W.; Barbot, S.; Avouac, J. P.


    The Los Angeles region is contracting at 8 mm/yr in the N 5° E direction due to the misalignment of the Mojave section of the San Andreas Fault with the direction of relative Pacific-North American plate motion. This contraction is accommodated by the accumulation of strain on thrust faults such as the Sierra Madre, Puente Hills and other systems and the release of that strain in damaging earthquakes such as the 1971 San Fernando, 1987 Whittier Narrows and 1994 Northridge shocks. A larger earthquake on one of these systems could constitute a worst-case-scenario event for Los Angeles, and so it is essential to use geodetic data to constrain where, and how quickly, tectonic strain is accumulating on these faults. This estimation problem is affected by 1) anthropogenic surface deformation that overprints tectonic contraction in geodetic data, 2) the complex 3D geometries of the relevant faults, and 3) the soft sedimentary basin underlying Los Angeles, which affects the elastostatic Green's functions that map slip rates on faults to velocities at the surface. Using 1) a GPS velocity field corrected for anthropogenic motions [Argus et al, 2005, and in prep.], 2) a detailed quadrilateral mesh of fault geometry based on an updated version of that in Marshall et al [2009] and on the SCEC CFM5.0 [Shaw et al, 2015], and 3) elastostatic Green's functions that incorporate the lateral and vertical heterogeneities in elastic properties represented by the SCEC CVM-H15.1, we obtain the most accurate geodesy-based picture of strain accumulation beneath Los Angeles to date. Among other results, we find that strain accumulation on strike-slip faults such as the Palos Verdes, Whittier-Elsinore and Raymond-Hollywood systems may cause an apparent N-S contractional gradient of 2 mm/yr across Los Angeles that is unrelated to thrust faulting, and that inferred strain accumulation rates on thrust faults are more readily reconciled with geologic slip rates when this strike-slip motion is

  10. A-Priori Rupture Models for Northern California Type-A Faults (United States)

    Wills, Chris J.; Weldon, Ray J.; Field, Edward H.


    . As a result, the modified segmented models discussed here only concern the San Andreas, Hayward-Rodgers Creek, and Calaveras faults. Given the extensive level of effort given by the recent Bay-Area WGCEP-2002, our approach has been to adopt their final average models as our preferred a-prior models. We have modified the WGCEP-2002 models where necessary to match data that were not available or not used by that WGCEP and where the models needed by WGCEP-2007 for a uniform statewide model require different assumptions and/or logic-tree branch weights. In these cases we have made what are usually slight modifications to the WGCEP-2002 model. This Appendix presents the minor changes needed to accomodate updated information and model construction. We do not attempt to reproduce here the extensive documentation of data, model parameters and earthquake probablilities in the WG-2002 report.

  11. The Greenville Fault: preliminary estimates of its long-term creep rate and seismic potential (United States)

    Lienkaemper, James J.; Barry, Robert G.; Smith, Forrest E.; Mello, Joseph D.; McFarland, Forrest S.


    Once assumed locked, we show that the northern third of the Greenville fault (GF) creeps at 2 mm/yr, based on 47 yr of trilateration net data. This northern GF creep rate equals its 11-ka slip rate, suggesting a low strain accumulation rate. In 1980, the GF, easternmost strand of the San Andreas fault system east of San Francisco Bay, produced a Mw5.8 earthquake with a 6-km surface rupture and dextral slip growing to ≥2 cm on cracks over a few weeks. Trilateration shows a 10-cm post-1980 transient slip ending in 1984. Analysis of 2000-2012 crustal velocities on continuous global positioning system stations, allows creep rates of ~2 mm/yr on the northern GF, 0-1 mm/yr on the central GF, and ~0 mm/yr on its southern third. Modeled depth ranges of creep along the GF allow 5-25% aseismic release. Greater locking in the southern two thirds of the GF is consistent with paleoseismic evidence there for large late Holocene ruptures. Because the GF lacks large (>1 km) discontinuities likely to arrest higher (~1 m) slip ruptures, we expect full-length (54-km) ruptures to occur that include the northern creeping zone. We estimate sufficient strain accumulation on the entire GF to produce Mw6.9 earthquakes with a mean recurrence of ~575 yr. While the creeping 16-km northern part has the potential to produce a Mw6.2 event in 240 yr, it may rupture in both moderate (1980) and large events. These two-dimensional-model estimates of creep rate along the southern GF need verification with small aperture surveys.

  12. [Andreas Vesalius in the Spanish Court]. (United States)

    Izumi, Hyonosuke


    After the publication of "Fabrica," Andreas Vesalius entered the Spanish court and became a court physician to Charles the Fifth, Holy Roman Emperor, and then to Philip the Second, Spanish king. The author studied this process and its historical background. The ancestors of Vesalius had close relations with the Hapsburgs and the dukes of BUrgundy, and served them as court physician or a court pharmacist. Vesalius was born in Brussels, obtained his degree at the University of Padua, Italy, became professor of anatomy and surgery there, and published "Tabulae Anatomicae Sex" and "Fabrica."In the ear of the Spanish court, the treatments of Henry the Second, French king, and of Don Carlos, Spanish crown prince, are famous among Vesalius' medical contributions. In the year of his resignation, Charles the Fifth conferred the title of count palatine on Vesalius.

  13. Andrea del Castagno. Última Cena

    Directory of Open Access Journals (Sweden)

    Tomás García-Salgado


    Full Text Available Apreciar la geometría como principio generador de la obra de arte es el objetivo de esta investigación. Es sabido que la reinvención de la perspectiva logró la conquista del espacio pictórico en la pintura renacentista, una aventura que tuvo su origen en los experimentos de elleschi, La Trinità de Masaccio y el tratado Della Pittura de Alberti. Dos décadas después de estos acontecimientos, nuestro personaje, Andrea del Castagno, comenzó a pintar un fresco en el convento de Santa Apolonia, plasmando una Última Cena en perspectiva dotada de un efecto ilusionístico. Nuestro objetivo es formular una hipótesis sobre la construcción de su trazo perspectivo, pues no hay evidencia –si la hubo– que revele su secreto.

  14. Strategie paratestuali nella lirica di Andrea Zanzotto

    Directory of Open Access Journals (Sweden)

    Matteo Tarricone


      A special perspective on the lyrics of Andrea Zanzotto is the constant reasoning on the constitutive aspects of poetry: an essential meditation to Zanzotto’s writing itself. Obviously, several different fundamental elements cannot but interact with this topic, such as the idea of landscape or of the lyrical I; influences of postmodernity on poetry; state of language and dialect, amongst others. They persist in any case on the background, though the central position is occupied by meta-reflection, which goes through and often matches many of the prevailing elements of this unique versification. Zanzotto expresses those concerns even by means of strategies with which he builds his collections; firstly, the paratext of his books, especially titles and notes; secondly, the distinctive feature of the twentieth - century canzoniere and the criteria designed to underline the strategies founding the collected works. There is really no lack of chance for research. Now, the hunt is on for the scented panther.

  15. The Terminology of Fault Zones in the Brittle Regime: Making Field Observations More Useful to the End User (United States)

    Shipton, Z.; Caine, J. S.; Lunn, R. J.


    , number and orientations of slip surfaces, variation in fracture density, relays, asperities, variable juxtaposition relationships etc. Problems can arise when "users" of structural geology try to apply models to general cases without understanding that these are simplified models. For example, when a section like the one in Chester and Logan 1996, gets projected infinitely into the third dimension along a fault the size of the San Andreas (seismology), or Shale Gouge Ratios are blindly applied to an Allen diagram without recognising that sub-seismic scale relays may provide "hidden" juxtapositions resulting in fluids bypassing low permeability fault cores. Phrases like 'low-permeability fault core and high-permeabilty damage zone' fail to appreciate fault zone complexity. Internicene arguments over the details of terminology that baffle the "end users" can make detailed field studies that characterise fault heterogeneity seem irrelevant. We argue that the field geology community needs to consider ways to make sure that we educate end-users to appropriate and cautious approaches to use of the data we provide with an appreciation of the uncertainties inherent in our limited ability to characterize 4D, tectonic structures, at the same time as understanding the value of carefully collected field data.

  16. New insights on Southern Coyote Creek Fault and Superstition Hills Fault (United States)

    van Zandt, A. J.; Mellors, R. J.; Rockwell, T. K.; Burgess, M. K.; O'Hare, M.


    Recent field work has confirmed an extension of the southern Coyote Creek (CCF) branch of the San Jacinto fault in the western Salton trough. The fault marks the western edge of an area of subsidence caused by groundwater extraction, and field measurements suggest that recent strike-slip motion has occurred on this fault as well. We attempt to determine whether this fault connects at depth with the Superstition Hills fault (SHF) to the southeast by modeling observed surface deformation between the two faults measured by InSAR. Stacked ERS (descending) InSAR data from 1992 to 2000 is initially modeled using a finite fault in an elastic half-space. Observed deformation along the SHF and Elmore Ranch fault is modeled assuming shallow (< 5 km) creep. We test various models to explain surface deformation between the two faults.

  17. Effects of Acknowledging Uncertainty about Earthquake Risk Estimates on San Francisco Bay Area Residents' Beliefs, Attitudes, and Intentions. (United States)

    Nakayachi, Kazuya; B Johnson, Branden; Koketsu, Kazuki


    We test here the risk communication proposition that explicit expert acknowledgment of uncertainty in risk estimates can enhance trust and other reactions. We manipulated such a scientific uncertainty message, accompanied by probabilities (20%, 70%, implicit ["will occur"] 100%) and time periods (10 or 30 years) in major (≥magnitude 8) earthquake risk estimates to test potential effects on residents potentially affected by seismic activity on the San Andreas fault in the San Francisco Bay Area (n = 750). The uncertainty acknowledgment increased belief that these specific experts were more honest and open, and led to statistically (but not substantively) significant increases in trust in seismic experts generally only for the 20% probability (vs. certainty) and shorter versus longer time period. The acknowledgment did not change judged risk, preparedness intentions, or mitigation policy support. Probability effects independent of the explicit admission of expert uncertainty were also insignificant except for judged risk, which rose or fell slightly depending upon the measure of judged risk used. Overall, both qualitative expressions of uncertainty and quantitative probabilities had limited effects on public reaction. These results imply that both theoretical arguments for positive effects, and practitioners' potential concerns for negative effects, of uncertainty expression may have been overblown. There may be good reasons to still acknowledge experts' uncertainties, but those merit separate justification and their own empirical tests. © 2017 Society for Risk Analysis.

  18. [Joonas Sildre ; Andreas Trossek. Narratiivsus piltides] / Sven Vabar

    Index Scriptorium Estoniae

    Vabar, Sven, 1977-


    Arvustus: Trossek, Andreas ; Sildre, Joonas. Narratiivsus piltides. Eesti '00 aastate autorikoomiks. Osa 2 = Narration in pictures. Estonian alternative comics from the '00s. Part 2. Tallinn : Haus Galerii, 2009

  19. Development of a Bayesian approach to assess the probability of concealed active faults using Helium isotope ratios: An example from the western Tottori area, SW Japan (United States)

    Martin, A. J.; Umeda, K.; Ishimaru, T.


    . Mariner (1997), Mantle fluids in the San Andreas fault system, California, Science, 278, 1278-1281. Umeda, K., K. Asamori, T. Negi, and T. Kusano (2011), A large intraplate earthquake triggered by latent magmatism, Jour. Geophys. Res., 116, B01207, doi:10.1029/2010JB007963.

  20. Faults Images (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Through the study of faults and their effects, much can be learned about the size and recurrence intervals of earthquakes. Faults also teach us about crustal...

  1. Fault Estimation

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, H.


    This paper presents a range of optimization based approaches to fault diagnosis. A variety of fault diagnosis prob-lems are reformulated in the so-called standard problem setup introduced in the literature on robust control. Once the standard problem formulations are given, the fault diagnosis pr...

  2. Structure of a shear zone at the base of the seismogenic zone, Norumbega fault system, Maine; Potential for comparison with upper-crustal fault structure (United States)

    Price, N. A.; Johnson, S. E.; Gerbi, C. C.; Koons, P. O.


    Studies of large strike-slip faults provide a detailed picture of the upper crustal structure of a seismogenic fault system (e.g. Chester et al., 1993; Ben-Zion and Sammis, 2003; Wibberley et al., 2008). Few studies have provided that same degree of detail for such faults at greater depths. Because of this, it is not well understood how the structure of the fault at the surface correlates with the structure of a fault with depth, particularly across the frictional-to-viscous transition. Our study of the Sandhill Corner shear zone (SCSZ) within the Norumbega fault system (a long-lived, subvertical, seismogenic fault system in Maine, USA) focuses on this depth level and provides an informative view of across and along strike variations within a shear zone from the base of the seismogenic zone. We suggest that the structure of this shear zone correlates with the structure of modern strike slip faults like the San Andreas. The SCSZ is a 300-500m wide shear zone exhumed from depths of ~10-15km that preserves mutually-overprinting pseudotachylyte and mylonite. Using over 100 samples from 6 transects, we considered the spatial variation in (1) quartz fabric intensity, grain size, and CPO data; (2) the prevalence of mineral-filled fractures and shattered porphyroclasts; and (3) the amount of pseudotachylyte (deformed and undeformed). We find a focused shear zone core (1-7m) that contains ultramylonite and phyllonite nearly devoid of porphyroclasts and rich in deformed pseudotachylyte with the finest sizes of quartz new grains. This core region is comparable to the focused core region of upper crustal faults rich in foliated gauge where most of the slip is thought to occur. The core of the SCSZ is surrounded by a wider zone of quartzofeldspathic mylonite and protomylonite, mylonitized calc-silicates, and sheared schist (~100-500m). There is an increased incidence of shattered porphyroclasts and deformed pseudotachylyte in these rocks with proximity to the fault core but

  3. [Epitome, an ignored work of Andreas Vesalius]. (United States)

    Vons, Jacqueline


    A few days before De humani corporis fabrica libri septem publication, in 1543, from Oporinus' office at Basel, a very large but not too bulky in-folio was published, which Andreas Vesalius, the author; offered as the Epitome or Summary of the seven Fabricae books. This work, written in latin, is divided into two parts: the first of them includes six chapters describing the human body, the second is composed of eleven anatomical plates with indices; the reader is invited to cut up the last two and stick them onto the preceding, so as to make a human three-dimensional figure. This method inserts the work in a modern conception of anatomical learning. Vesalius involves himself patiently gives many explanations for learning the body in dissection order through plates and text as well. But these plates--and most of them are different from those in the Fabrica-, are not simple illustrations, but play an active part in anatomical knowledge acquisition, just as the text does, but through a different access. We will attract your attention on this originality, often ignored, of the Epitome.

  4. Rhazes in the renaissance of Andreas Vesalius. (United States)

    Compier, Abdul Haq


    Andreas Vesalius' (1514-64) first publication was a Paraphrasis of the ninth book of the Liber ad Almansorem, written by the Arab-Persian physician and alchemist Rhazes (854-925). The role of Rhazes in Vesalius' oeuvre has thus far been much disregarded. The different ways Rhazes recurs reveal an intellectual evolution in Vesalius' work. In the Paraphrasis, Vesalius subjects Rhazes to the authority of Galen in the context of the early sixteenth-century humanist campaign for the substitution of Arab influences by Greek 'originals'. Over the years Vesalius continues his work on Rhazes, but his approach becomes more internationalistic. Ultimately, Vesalius criticises Galen while expressing sympathy for the Arab author. This may be the more significant as Rhazes could have influenced Vesalius in the act of criticising Galen - critical discussions of Galen were available to Vesalius in Latin translations of Rhazes's Liber Continens. Although Vesalius never refers to the work, it is hardly possible he was unaware of it: similarities in structure, rhetoric and form between the Continens and the De humani corporis fabrica could support this hypothesis.

  5. Andreas Vesalius' understanding of pulmonary ventilation. (United States)

    Hage, J Joris; Brinkman, Romy J


    The historical evolution of understanding of the mechanical aspects of respiration is not well recorded. That the anatomist Andreas Vesalius (1515-1564) first recorded many of these mechanics in De Humani Corporis Fabrica Libri Septem has received little attention. We searched a digital copy of De Fabrica (1543) and its English translation as provided by Richardson and Carman (1998-2009) for references to aspects of pulmonary ventilation. We found that Vesalius grasped the essentials of tidal and forced respiration. He recognized that atmospheric pressure carried air into the lungs, approximately 100 years before Borelli did. He described an in vivo experiment of breathing, some 120 years before John Mayow produced his artificial model. He reported on positive pressure ventilation through a tracheotomy and on its life-saving effect, some 100 years before Robert Hook did. In publicly recording his insights over 450 years ago, Vesalius laid a firm basis for our understanding of the physiology of respiration and the management of its disorders. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Comparative mineral chemistry and textures of SAFOD fault gouge and damage-zone rocks (United States)

    Moore, Diane E.


    Creep in the San Andreas Fault Observatory at Depth (SAFOD) drillhole is localized to two foliated gouges, the central deforming zone (CDZ) and southwest deforming zone (SDZ). The gouges consist of porphyroclasts of serpentinite and sedimentary rock dispersed in a foliated matrix of Mg-smectite clays that formed as a result of shearing-enhanced reactions between the serpentinite and quartzofeldspathic rocks. The CDZ takes up most of the creep and exhibits differences in mineralogy and texture from the SDZ that are attributable to its higher shearing rate. In addition, a ∼0.2-m-wide sector of the CDZ at its northeastern margin (NE-CDZ) is identical to the SDZ and may represent a gradient in creep rate across the CDZ. The SDZ and NE-CDZ have lower clay contents and larger porphyroclasts than most of the CDZ, and they contain veinlets and strain fringes of calcite in the gouge matrix not seen elsewhere in the CDZ. Matrix clays in the SDZ and NE-CDZ are saponite and corrensite, whereas the rest of the CDZ lacks corrensite. Saponite is younger than corrensite, reflecting clay crystallization under declining temperatures, and clays in the more actively deforming portions of the CDZ have better equilibrated to the lower-temperature conditions.

  7. Provenance of alluvial fan deposits to constrain the mid-term offsets along a strike-slip active fault: the Elsinore fault in the Coyote Mountains, Imperial Valley, California. (United States)

    Masana, Eulalia; Stepancikova, Petra; Rockwell, Thomas


    The lateral variation in rates along a fault and its constancy along time is a matter of discussion. To give light to this discussion, short, mid and long term offset distribution along a fault is needed. Many studies analyze the short-term offset distribution along a strike-slip fault that can be obtained by the analysis of offset features imprinted in the morphology of the near-fault area. We present an example on how to obtain the mid- to long-term offset values based on the composition of alluvial fans that are offset by the fault. The study area is on the southern tip of the Elsinore fault, which controls the mountain front of the Coyote Mountains (California). The Elsinore-Laguna Salada fault is part of the San Andreas fault (SAF) system, extending 250 km from the Los Angeles Basin southeastward into the Gulf of California, in Mexico. The slip-rate on the southern Elsinore fault is believed to be moderate based on recent InSAR observations, although a recent study near Fossil Canyon (southern Coyote Mountains) suggests a rate in the range of 1-2 mm/yr. For this study we processed the airborne LiDAR dataset (EarthScope Southern & Eastern California, SoCal) to map short to mid-term alluvial offsets. We reprocessed the point clouds to produce DEMs with 0.5m and 0.25m grids and we varied the insolation angles to illuminate the various fault strands and the offset features. We identified numerous offset features, such as rills, channel bars, channel walls, alluvial fans, beheaded channels and small erosional basins that varied in displacement from 1 to 350 m. For the mid- to long-term offsets of the alluvial fans we benefited from the diverse petrological composition of their sources. Moreover, we recognized that older alluvium, which is offset by greater amounts, is in some cases buried beneath younger alluvial fan deposits and separated by buried soils. To determine the source canyon of various alluvial elements, we quantified the clast assemblage of each source

  8. Finding faults

    Energy Technology Data Exchange (ETDEWEB)

    Barber, J.; Duke, J. [Surpac Minex Group (Australia)


    The Surpac Minex Group has been building a geologic model to represent the coal seam structure at the Carbones del Cerrejon LLC mine in north eastern Colombia which is bonded by major reserve and normal faults. This is being achieved through a new software faulting tool. The tool combines existing Minex modelling with new fault interpretation tools. New software that permits 3-D photogrammetry and seismic data can also be incorporated. 6 figs.

  9. Deep underground recording of induced and natural earthquakes to investigate rupture processes and fault-zone strength (United States)

    McGarr, A.; Boettcher, M. S.; Fletcher, J. B.; Johnston, M. J.


    Seismic recording systems, installed at deep levels in mines or boreholes, yield seismograms from nearby earthquakes that are relatively free of ambient noise and secondary arrivals. This makes it straightforward to determine moment tensors and other source parameters of interest. The maximum slip within an earthquake rupture zone, inferred from the velocity pulse of the S wave, is combined with the seismic moment to define a laboratory stick-slip friction experiment that has the same maximum slip rate and yield stress as the earthquake. Ground motions from mining-induced earthquakes, of about M2, recorded using broadband stations installed at depths between 2 and 3.6 km in two of the deepest gold mines in South Africa were analyzed in this way to infer peak slip rates ranging up to about 10 m/s and yield stresses of as much as 150 MPa. Because the near-fault peak ground velocity is about half of the maximum slip rate, this result indicates that underground support should be capable of withstanding peak ground velocities of 5 m/s. Analysis of 11 mine tremors resulted in a median maximum slip rate of 3.8 m/s and a median yield stress of 62 MPa. The same analysis of ground motion from a M2.1 repeating earthquake near Parkfield, California, recorded in October 2003 using an extensive string of seismometers installed at depth in the SAFOD pilot hole, revealed similar results, a maximum slip rate of 4 m/s and a yield stress of 64 MPa. This similarity is somewhat unexpected in view of tectonic settings and pore pressures that are quite different. Whereas the mining-induced earthquakes occur in a stable tectonic setting and zero pore pressure environment, repeating earthquakes along the San Andreas are due to active plate-boundary faulting at hydrostatic pore pressure, at least near SAFOD. Analyses of heat flow data indicate that the shear strength of the San Andreas fault near SAFOD is less than 20 MPa and in situ stress measurements there show that the regional shear

  10. 3D Mechanical Modeling of Earthquake Cycle on a Frictional Strike-Slip Fault Embedded in a Viscoelastic Lithosphere (United States)

    Chery, J.; Provost, A.; Hassani, R.


    Large earthquakes do not occur regularly. They often happen as sequences or clusters, which are separated by long period of quiescence. For example, the north Anatolian fault, which produced more than ten large eartquakes bewteen 1939 and 1999, has been relatively quiet during the centuries before. Understanding the causes of this behaviour is essential to produce a realistic model of seismic hazard. Three phases have to be accounted for in order to model the seismic cycle 1) the secular loading due to differential plate motion 2) the coseismic motion which is controlled by slip or slip rate weakening 3) the postseismic relaxation which corresponds to deep viscous motion of the crust or to localized fault slip. We present here an attempt to develop such a model for a large strike-slip fault such as the north Anatolian fault or the San Andreas fault. We use a 3D finite element code to in order to obtain both a realistic description of the horizontal motion and of the rheological variation of the lithosphere with depth. We use a linear viscoelastic law for the lithosphere. The viscosity of the upper part is scaled to obtain a realistic stress magnitude in the upper crust. The viscosity of the middle crust decreases according to temperature dependent viscosity. The friction law corresponds to the use of the Coulomb criterion with a static coefficient of friction higher than its dynamic value. The time integration of the mechanical system is done using a finite difference scheme coupled with the dynamic relaxation method. A prescribed velocity is applied laterally and at the base of the model. After a loading phase of stress buildup of the crust, earthquakes of various size and amplitude progressively occur. A fundamental difference with the 2D approach is that earthquake occurrence is not regular, probably due to the supplementary degree of freedom provided in the strike direction. We analyse the behaviour of our system in term of scaling law, and study in which

  11. Earthquake Surface Fault Rupture Interaction with Building Foundations


    Oettle, Nicolas Karl


    Recent earthquakes have provided numerous examples of the devastating effects of earthquake surface fault rupture on structures. Several major cities are built in areas containing active faults that can break the ground surface (e.g., Los Angeles, Salt Lake City, San Diego, San Francisco, and Seattle). Along with the often spectacular observations of damage, examples of satisfactory performance of structures were also observed. These examples of satisfactory performance indicate that similar ...

  12. Andreas Vesalius and his De humani corporis Fabrica libri septem. (United States)

    Steele, Lloyd


    Andreas Vesalius of Brussels (1514-1564) was a Renaissance physician and surgeon whose most famous work was the De humani corporis fabrica libri septem a monograph describing human anatomy, first published in 1543. The Fabrica precipitated advances both anatomical and pedagogical, and its influence was such that Vesalius has since been described as the 'founder of modern anatomy'.

  13. Andreas Riis: a lifetime of colonial drama | Quartey | Research ...

    African Journals Online (AJOL)

    This article traces the adventures of Andreas Riis, a missionary assigned to the Gold Coast (West Africa) by the Basel Mission in the nineteenth century, as a narrative of landscapes, local inhabitants and power to show the complexity of missionary discourse. Various unpublished documents from the Basel Mission Archive ...

  14. Venemaa kaksipidine moslemipärand / Andreas Kappeler

    Index Scriptorium Estoniae

    Kappeler, Andreas, 1943-


    Viini ülikooli Ida-Euroopa ajaloo instituudi direktori Andreas Kappeleri sõnul on Tshethseenia sõda sobivam võrrelda teiste dekoloniseerimisajastu suurte sõdadega, kui näha seda tsivilisatsioonide kokkupõrkena või terrorismivastase sõjana

  15. Au tööle / Andreas Trossek, Margus Tamm

    Index Scriptorium Estoniae

    Trossek, Andreas, 1980-


    Vastuseks Mari Laanemetsa ja Indrek Sirkli artiklike "Elu on läinud paremaks, elu on läinud lõbusamaks ...?" (Sirp, 2009, 31. 07, lk. 18-19) Eesti kunsti ja visuaalkultuuri ajakirja "" 2009. aasta nr. 1-2 sisu ja kujunduse kohta. Ajakirja uus toimetus: Andreas Trossek - peatoimetaja, Heie Treier, Ave Randviir, kujundaja Margus Tamm

  16. Andrea Passoni, Economia delle piattaforme e architettura digitale delle scelte

    Directory of Open Access Journals (Sweden)

    Maria Chiara Pievatolo


    Full Text Available Andrea Passoni ha depositato sull’archivio Marini Economia delle piattaforme e architettura digitale delle scelte. Appunti sull’alternativa cooperativa, su un tema di grande attualità, la cosiddetta sharing economy. A dispetto del nome accattivante, molte delle sue esperienze più note ricadono nel...

  17. Andrea Passoni, Giustizia come equità e socialismo liberale

    Directory of Open Access Journals (Sweden)

    Maria Chiara Pievatolo


    Full Text Available L'articolo di Andrea Passoni, Giustizia come equità e socialismo liberale, appena pubblicato nell'archivio "Giuliano Marini", discute l’idea rawlsiana di socialismo liberale, allo scopo di dimostrare che può essere almeno parzialmente riempire di significato tramite la promozione e lo sviluppo di un’economia di mercato di tipo cooperativo.

  18. Fault diagnosis (United States)

    Abbott, Kathy


    The objective of the research in this area of fault management is to develop and implement a decision aiding concept for diagnosing faults, especially faults which are difficult for pilots to identify, and to develop methods for presenting the diagnosis information to the flight crew in a timely and comprehensible manner. The requirements for the diagnosis concept were identified by interviewing pilots, analyzing actual incident and accident cases, and examining psychology literature on how humans perform diagnosis. The diagnosis decision aiding concept developed based on those requirements takes abnormal sensor readings as input, as identified by a fault monitor. Based on these abnormal sensor readings, the diagnosis concept identifies the cause or source of the fault and all components affected by the fault. This concept was implemented for diagnosis of aircraft propulsion and hydraulic subsystems in a computer program called Draphys (Diagnostic Reasoning About Physical Systems). Draphys is unique in two important ways. First, it uses models of both functional and physical relationships in the subsystems. Using both models enables the diagnostic reasoning to identify the fault propagation as the faulted system continues to operate, and to diagnose physical damage. Draphys also reasons about behavior of the faulted system over time, to eliminate possibilities as more information becomes available, and to update the system status as more components are affected by the fault. The crew interface research is examining display issues associated with presenting diagnosis information to the flight crew. One study examined issues for presenting system status information. One lesson learned from that study was that pilots found fault situations to be more complex if they involved multiple subsystems. Another was pilots could identify the faulted systems more quickly if the system status was presented in pictorial or text format. Another study is currently under way to

  19. San Francisco District Laboratory (SAN) (United States)

    Federal Laboratory Consortium — Program CapabilitiesFood Analysis SAN-DO Laboratory has an expert in elemental analysis who frequently performs field inspections of materials. A recently acquired...

  20. MX Siting Investigation. Geotechnical Report. Volume IIB. Gila Bend Group and White Sands Missile Range Extension. (United States)


    taken to be the San Andreas, Sand Hills, and Algodones faults. Recorded seismicity within the zone adjacent the study area includes many earthquakes of...earthquakes with 8+ magnitudes. Therefore, the San Andreas, Sand Bills, and Algodones faults have been considered capable of producing an earthquake of

  1. San Marino. (United States)


    San Marino, an independent republic located in north central Italy, in 1983 had a population of 22,206 growing at an annual rate of .9%. The literacy rate is 97% and the infant mortality rate is 9.6/1000. The terrain is mountainous and the climate is moderate. According to local tradition, San Marino was founded by a Christian stonecutter in the 4th century A.D. as a refuge against religious persecution. Its recorded history began in the 9th century, and it has survived assaults on its independence by the papacy, the Malatesta lords of Rimini, Cesare Borgia, Napoleon, and Mussolini. An 1862 treaty with the newly formed Kingdom of Italy has been periodically renewed and amended. The present government is an alliance between the socialists and communists. San Marino has had its own statutes and governmental institutions since the 11th century. Legislative authority at present is vested in a 60-member unicameral parliament. Executive authority is exercised by the 11-member Congress of State, the members of which head the various administrative departments of the goverment. The posts are divided among the parties which form the coalition government. Judicial authority is partly exercised by Italian magistrates in civil and criminal cases. San Marino's policies are tied to Italy's and political organizations and labor unions active in Italy are also active in San Marino. Since World War II, there has been intense rivalry between 2 political coalitions, the Popular Alliance composed of the Christian Democratic Party and the Independent Social Democratic Party, and the Liberty Committee, coalition of the Communist Party and the Socialist Party. San Marino's gross domestic product was $137 million and its per capita income was $6290 in 1980. The principal economic activities are farming and livestock raising, along with some light manufacturing. Foreign transactions are dominated by tourism. The government derives most of its revenue from the sale of postage stamps to

  2. Geotechnical Extreme Events Reconnaissance Report on the Performance of Structures in Densely Urbanized Areas Affected by Surface Fault Rupture During the August 24, 2014 M6 South Napa Earthquake, California, USA. (United States)

    Cohen-Waeber, J.; Lanzafame, R.; Bray, J.; Sitar, N.


    The August 24, 2014, M­w 6.0 South Napa earthquake is the largest seismic event to have occurred in the San Francisco Bay Region, California, USA, since the Mw 6.9 1989 Loma Prieta earthquake. The event epicenter occurred at the South end of the Napa Valley, California, principally rupturing northwest along parts of the active West Napa fault zone. Bound by two major fault zones to the East and West (Calaveras and Rogers Creek, respectively), the Napa Valley is filled with up to 170 m. of alluvial deposits and is considered to be moderately to very highly susceptible to liquefaction and has the potential for violent shaking. While damage due to strong ground shaking was significant, remarkably little damage due to liquefaction or landslide induced ground deformations was observed. This may be due to recent drought in the region. Instead, the South Napa earthquake is the first to produce significant surface rupture in this area since the Mw 7.9 1906 San Andreas event, and the first in Northern California to rupture through a densely urbanized environment. Clear expressions of surface fault rupture extended approximately 12 - 15 km northward from the epicenter and approximately 1-2 km southeast with a significant impact to infrastructure, including roads, lifelines and residential structures. The National Science Foundation funded Geotechnical Extreme Events Reconnaissance (GEER) Association presents here its observations on the performance of structures affected by surface fault rupture, in a densely populated residential neighborhood located approximately 10 km north of the epicenter. Based on the detailed mapping of 27 residential structures, a preliminary assessment of the quantitative descriptions of damage shows certain characteristic interactions between surface fault rupture and the overlying infrastructure: 48% of concrete slabs cracked up to 8 cm wide, 19% of structures shifted up to 11 cm off of their foundation and 44% of foundations cracked up to 3 cm

  3. Strike-slip faulting in the Inner California Borderlands, offshore Southern California. (United States)

    Bormann, J. M.; Kent, G. M.; Driscoll, N. W.; Harding, A. J.; Sahakian, V. J.; Holmes, J. J.; Klotsko, S.; Kell, A. M.; Wesnousky, S. G.


    In the Inner California Borderlands (ICB), offshore of Southern California, modern dextral strike-slip faulting overprints a prominent system of basins and ridges formed during plate boundary reorganization 30-15 Ma. Geodetic data indicate faults in the ICB accommodate 6-8 mm/yr of Pacific-North American plate boundary deformation; however, the hazard posed by the ICB faults is poorly understood due to unknown fault geometry and loosely constrained slip rates. We present observations from high-resolution and reprocessed legacy 2D multichannel seismic (MCS) reflection datasets and multibeam bathymetry to constrain the modern fault architecture and tectonic evolution of the ICB. We use a sequence stratigraphy approach to identify discrete episodes of deformation in the MCS data and present the results of our mapping in a regional fault model that distinguishes active faults from relict structures. Significant differences exist between our model of modern ICB deformation and existing models. From east to west, the major active faults are the Newport-Inglewood/Rose Canyon, Palos Verdes, San Diego Trough, and San Clemente fault zones. Localized deformation on the continental slope along the San Mateo, San Onofre, and Carlsbad trends results from geometrical complexities in the dextral fault system. Undeformed early to mid-Pleistocene age sediments onlap and overlie deformation associated with the northern Coronado Bank fault (CBF) and the breakaway zone of the purported Oceanside Blind Thrust. Therefore, we interpret the northern CBF to be inactive, and slip rate estimates based on linkage with the Holocene active Palos Verdes fault are unwarranted. In the western ICB, the San Diego Trough fault (SDTF) and San Clemente fault have robust linear geomorphic expression, which suggests that these faults may accommodate a significant portion of modern ICB slip in a westward temporal migration of slip. The SDTF offsets young sediments between the US/Mexico border and the

  4. Optimal fault signal estimation

    NARCIS (Netherlands)

    Stoorvogel, Antonie Arij; Niemann, H.H.; Saberi, A.; Sannuti, P.


    We consider here both fault identification and fault signal estimation. Regarding fault identification, we seek either exact or almost fault identification. On the other hand, regarding fault signal estimation, we seek either $H_2$ optimal, $H_2$ suboptimal or Hinfinity suboptimal estimation. By

  5. Andreas Vesalius 500 years - A Renaissance that revolutionized cardiovascular knowledge

    Directory of Open Access Journals (Sweden)

    Evandro Tinoco Mesquita


    Full Text Available AbstractThe history of medicine and cardiology is marked by some geniuses who dared in thinking, research, teaching and transmitting scientific knowledge, and the Italian Andreas Vesalius one of these brilliant masters. His main scientific work "De Humani Corporis Fabrica" is not only a landmark study of human anatomy but also an artistic work of high aesthetic quality published in 1543. In the year 2014 we celebrated 500 years since the birth of the brilliant professor of Padua University, who with his courage and sense of observation changed the understanding of cardiovascular anatomy and founded a school to date in innovative education and research of anatomy. By identifying "the anatomical errors" present in Galen's book and speech, he challenged the dogmas of the Catholic Church, the academic world and the doctors of his time. However, the accuracy of his findings and his innovative way to disseminate them among his students and colleagues was essential so that his contributions are considered by many the landmark of modern medicine. His death is still surrounded by mysteries having different hypotheses, but a certainty, suffered sanctions of the Catholic Church for the spread of their ideas. The cardiologists, cardiovascular surgeons, interventional cardiologists, electrophysiologists and cardiovascular imaginologists must know the legacy of genius Andreas Vesalius that changed the paradigm of human anatomy.

  6. Andreas Vesalius 500 years - A Renaissance that revolutionized cardiovascular knowledge (United States)

    Mesquita, Evandro Tinoco; de Souza Júnior, Celso Vale; Ferreira, Thiago Reigado


    The history of medicine and cardiology is marked by some geniuses who dared in thinking, research, teaching and transmitting scientific knowledge, and the Italian Andreas Vesalius one of these brilliant masters. His main scientific work "De Humani Corporis Fabrica" is not only a landmark study of human anatomy but also an artistic work of high aesthetic quality published in 1543. In the year 2014 we celebrated 500 years since the birth of the brilliant professor of Padua University, who with his courage and sense of observation changed the understanding of cardiovascular anatomy and founded a school to date in innovative education and research of anatomy. By identifying "the anatomical errors" present in Galen's book and speech, he challenged the dogmas of the Catholic Church, the academic world and the doctors of his time. However, the accuracy of his findings and his innovative way to disseminate them among his students and colleagues was essential so that his contributions are considered by many the landmark of modern medicine. His death is still surrounded by mysteries having different hypotheses, but a certainty, suffered sanctions of the Catholic Church for the spread of their ideas. The cardiologists, cardiovascular surgeons, interventional cardiologists, electrophysiologists and cardiovascular imaginologists must know the legacy of genius Andreas Vesalius that changed the paradigm of human anatomy. PMID:26107459

  7. Fault zone fabric and fault weakness

    NARCIS (Netherlands)

    Collettini, C.; Niemeijer, A.; Viti, C.; Marone, C.


    Geological and geophysical evidence suggests that some crustal faults are weak1–6 compared to laboratory measurements of frictional strength7. Explanations for fault weakness include the presence of weak minerals4, high fluid pressures within the fault core8,9 and dynamic processes such as

  8. Andreas Vesalius (1514-1564) - an unfinished life. (United States)

    Ambrose, Charles T


    The fame of Andreas Vesalius (1514-1564) rests on his anatomy text, De humani corporis fabrica, regarded as a seminal book in modern medicine. It was compiled while he taught anatomy at Padua, 1537-1543. Some of his findings challenged Galen's writings of the 2c AD, and caused De fabrica to be rejected immediately by classically trained anatomists. At age 29, Vesalius abandoned his studies and over the next two decades served as physician to Emperor Charles V of the Holy Roman Empire (HRE) and later to King Philip II of Spain in Madrid. In 1564, he sought to resume teaching anatomy in Padua, but release from royal service obliged him first to make a pilgrimage to Palestine. During the return voyage to Venice, he became ill and was put ashore alone on an Ionian island Zakynthos, where he died days later at age 50.

  9. The Last Months of Andreas Vesalius: a Coda. (United States)

    Biesbrouck, Maurits; Goddeeris, Theodoor; Steeno, Omer


    Since the publication in this journal of our two articles on the end of Andreas Vesalius' life, some very old sources have recently become available that we were unable to consult at the time of writing and that now prompt us to add a coda. These sources give an even better picture of both the circumstances of the disaster that led to Vesalius' death and the correct site of his burial. Firstly, there is a text by Reinerus Solenander that casts a completely different light on the circumstances in which his ship was at sea and the way in which it reached land; in addition, there is a new early eye-witness report of his burial-place by Christoph Fürer von Haimendorf, dating from 6 August 1565.

  10. El perfil de Andrea Pozzo como maestro de perspectiva

    Directory of Open Access Journals (Sweden)

    Sara Fuentes Lázaro

    Full Text Available Resumen La influencia internacional del arquitecto, cuadraturista y constructor de aparatos efímeros Andrea Pozzo (1642-1709 se debió principalmente a la amplia difusión de su tratado Perspectiva Pictorum Architectorum (Roma 1693-1700. Pozzo ofrecía en estos volúmenes, además de los modelos perspectivos aprendidos de Vignola, Pietro Accolti y Jean Dubreuil, entre sus fuentes más evidentes, un método simplificado de creación personal. Su técnica estaba ideada para resolver cualquier representación de arquitectura desde diferentes puntos de vista utilizando solamente procedimientos gráficos que no implicaban ninguna operación matemática. El perfil como perspectivo de Andrea Pozzo se caracterizó por combinar la formación intelectual y técnica adquirida en las librerías de la Orden, con su experiencia como maestro de un desarrollado taller y una importante ambición artística que contrasta con otras publicaciones de su época presuntamente similares en función y contenido (como L'architettura civile ridotta a' metodo facile e breve de F. Eschinardi. La obra de Pozzo constituye el último estadio en la divulgación de la técnica perspectiva, a través de un plan docente fácilmente aplicable a cualquier ámbito de la arquitectura y la pintura, en el que confluyen la tradición óptico-perceptiva y el dominio geométrico-matemático.

  11. Yupingfeng San (United States)

    Liu, Xue; Shen, Jiawen; Fan, Danping; Qiu, Xuemei; Guo, Qingqing; Zheng, Kang; Luo, Hui; Shu, Jun; Lu, Cheng; Zhang, Ge; Lu, Aiping; Ma, Chaoying; He, Xiaojuan


    Yupingfeng San (YPFS) is a representative Traditional Chinese Medicine (TCM) formula with accepted therapeutic effect on Asthma. However, its action mechanism is still obscure. In this study, we used network pharmacology to explore potential mechanism of YPFS on asthma. Nucleotide-binding oligomerization domain (NOD)-like receptor pathway was shown to be the top one shared signaling pathway associated with both YPFS and asthma. In addition, NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome was treated as target protein in the process of YPFS regulating asthma. Further, experimental validation was done by using LPS-stimulated U937 cells and ovalbumin (OVA)-sensitized BALB/c mice model. In vitro experiments showed that YPFS significantly decreased the production of TNF-α and IL-6, as well as both mRNA and protein levels of IL-1β, NLRP3, Caspase-1 and ASC in LPS-stimulated U937 cells. In vivo experiment indicated that YPFS treatment not only attenuated the clinical symptoms, but also reduced inflammatory cell infiltration, mucus secretion and MUC5AC production in lung tissue of asthmatic mice. Moreover, YPFS treatment remarkably decreased the mRNA and protein levels of IL-1β, NLRP3, Caspase-1 and ASC in lung tissue of asthmatic mice. In conclusion, these results demonstrated that YPFS could inhibit NLRP3 inflammasome components to attenuate the inflammatory response in asthma.

  12. Structure of the Newport-Inglewood/Rose Canyon and Palos Verdes Fault Zones and Implications for Current Fault Models (United States)

    Sahakian, V. J.; Bormann, J. M.; Klotsko, S.; Holmes, J. J.; Driscoll, N. W.; Harding, A. J.; Kent, G.; Wesnousky, S. G.


    Faulting in the Inner California Borderlands is complex. In the past, this region has undergone various deformational events such as extensional and rotational deformation to variable strike-slip deformation; this has imparted the geomorphology and fault structures observed offshore Southern California. Several hypotheses have been proposed to explain the current fault structures and the hazards they pose to populated coastal regions. The geometry and architecture of these structures can have significant implications for ground motions in the event of a rupture, and therefore impact working models of hazard assessment. Here, focusing on the Newport-Inglewood/Rose Canyon (NI/RC) and Palos Verdes (PV) fault zones, we use new and existing multibeam, CHIRP and Multi-Channel Seismic (MCS) data to describe the geometry of the fault system. We interpret reprocessed (prestack time migration) MCS data collected in 1979, 1986, and 2006 as well as newly acquired high-res MCS datasets collected offshore San Diego County. Combining these high and intermediate resolution datasets with very high resolution CHIRP data, we define structures that show distinct changes in the style of deformation through time, and place constraints on the segmentation of faults in this system. The timing of the most recent deformation on the NI/RC appears to vary along-strike. Likewise, the NI/RC fault's dip direction and angle appears to vary along-strike, and these changes in dip seem to mark the boundaries of restraining and releasing bends. Additionally, the NI/RC fault appears to die away to the north, possibly partitioning its strain on to the PV fault. We will present interpretations of the faults' current deformational activity as well as likelihood of rupture propagating across releasing/restraining bends, and discuss how this impacts current fault models that are employed for hazard assessment for Los Angeles and San Diego counties.

  13. Uudised : Juuksur - uus live-muusika lokaal. Madonna tögas Bushi. Andrea Bocelli Helsingis

    Index Scriptorium Estoniae


    Kontserdil 19. mail Tallinnas (Vaimu 1) õhtulokaali "Juuksur" avamisel esineb jazzrokki viljelev ansambel Wrupk Urei ja 26. mail Allan Vainola sooloprojektiga. Ameerika poplauljast Madonnast. Itaalia tenori Andrea Bocelli kontserdist 19. nov. Hartwall Arenal Helsingis

  14. Triumphing over the Enemy. References to the Turks as Part of Andrea, Giannettino and Giovanni Andrea Doria’s Artistic Patronage and Public Image

    Directory of Open Access Journals (Sweden)

    Laura Stagno


    Andrea Doria (1466-1560 e in seguito il suo erede, Giovanni Andrea I (1550-1606, quali “generali del mare” per la corona spagnola, ebbero un ruolo cruciale nella strategia a lungo termine di lotta contro il nemico turco e di contenimento del suo potere. Ariosto, nel suo Orlando Furioso, celebrò Andrea come nuovo e più glorioso Pompeo, in grado di liberare il mare dai corsari ottomani, e numerosi altri testi coevi ne esaltarono le gesta contro il Turco. Scopo dell’articolo è quello di indagare in che modo tale ruolo si sia tradotto in termini di rappresentazione figurativa, in riferimento al  grande ammiraglio, ma anche al suo luogotente ed erede designato, Giannettino (ucciso nel corso della congiura dei Fieschi, nel 1547 e del  figlio di questi, Giovanni Andrea, che appunto in ragione della morte prematura del padre succedette al grande ammiraglio. Tra le commissioni artistiche dei Doria si riscontrano riferimenti al nemico turco in statue e placchette, nell’articolata serie di arazzi dedicati alla battaglia di Lepanto, ma anche nella complessa raffigurazione allegorica del passaggio del potere dal vecchio principe al giovane erede. Il tipo di approccio al tema risulta però diverso: mediato da riferimenti classici e simbolici nel caso di Andrea, più diretto in quello del successore. In parallelo al patronage dei due Doria ha un ruolo di grande importanza la committenza della Repubblica genovese,  alla quale si lega la prima iconografia che, nella statua colossale “all’antica” eseguita da Montorsoli (1539, presenta in modo esplicito il trionfo di Andrea sugli Ottomani, secondo un’iconografia.


    Directory of Open Access Journals (Sweden)

    Kukuh Yudha Karnanta


    Full Text Available The article entitled Sastra ‘Mungkin’:  A Symbolic contestation of  Andrea Hirata in Indonesian Literature Arena is discussing the literary practices of  Andrea Hirata, a novelist who surprisingly popular in Indonesian literature from 2006 to present.  This article aims to explicit the views and contestation of  Andrea Hirata literary practices based on his views in gaining legitimacy of  his works as an author. This research applies Pierre Bourdieu’s Arena Cultural Production, which assumes that literature is not just a question of  aesthetics but also the struggle of positions between agents operating in the literary arena. According to the research that has been conducted, the result reveals that Andrea Hirata actually has a tendency, furthermore, obsession, in order to gain a specific legitimacy as an author (literar y figure. In doing so, Andrea Hirata impose his views about possibility in Indonesian literature. Keywords: field, Andrea Hirata, symbolic violence, legitimacy, doxa, heterodoxa

  16. San Mateo Creek Basin (United States)

    The San Mateo Creek Basin comprises approximately 321 square miles within the Rio San Jose drainage basin in McKinley and Cibola counties, New Mexico. This basin is located within the Grants Mining District (GMD).

  17. Fault detection and isolation in systems with parametric faults

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, Hans Henrik


    The problem of fault detection and isolation of parametric faults is considered in this paper. A fault detection problem based on parametric faults are associated with internal parameter variations in the dynamical system. A fault detection and isolation method for parametric faults is formulated...

  18. Iowa Bedrock Faults (United States)

    Iowa State University GIS Support and Research Facility — This fault coverage locates and identifies all currently known/interpreted fault zones in Iowa, that demonstrate offset of geologic units in exposure or subsurface...

  19. Layered Fault Management Architecture

    National Research Council Canada - National Science Library

    Sztipanovits, Janos


    ... UAVs or Organic Air Vehicles. The approach of this effort was to analyze fault management requirements of formation flight for fleets of UAVs, and develop a layered fault management architecture which demonstrates significant...

  20. Software fault tolerance


    Kazinov, Tofik Hasanaga; Mostafa, Jalilian Shahrukh


    Because of our present inability to produce errorfree software, software fault tolerance is and will contiune to be an important consideration in software system. The root cause of software design errors in the complexity of the systems. This paper surveys various software fault tolerance techniquest and methodologies. They are two gpoups: Single version and Multi version software fault tolerance techniques. It is expected that software fault tolerance research will benefit from this research...

  1. Rapid, decimeter-resolution fault zone topography mapped with Structure from Motion (United States)

    Johnson, K. L.; Nissen, E.; Saripalli, S.; Arrowsmith, R.; McGarey, P.; Scharer, K. M.; Williams, P. L.


    Recent advances in the generation of high-resolution topography have revolutionized our ability to detect subtle geomorphic features related to ground-rupturing earthquakes. Currently, the most popular topographic mapping methods are airborne Light Detection And Ranging (LiDAR) and terrestrial laser scanning (TLS). Though powerful, these laser scanning methods have some inherent drawbacks: airborne LiDAR is expensive and can be logistically complicated, while TLS is time consuming even for small field sites and suffers from patchy coverage due to its restricted field-of-view. An alternative mapping technique, called Structure from Motion (SfM), builds upon traditional photogrammetry to reproduce the topography and texture of a scene from photographs taken at varying viewpoints. The improved availability of cheap, unmanned aerial vehicles (UAVs) as camera platforms further expedites data collection by covering large areas efficiently with optimal camera angles. Here, we introduce a simple and affordable UAV- or balloon-based SfM mapping system which can produce dense point clouds and sub-decimeter resolution digital elevation models (DEMs) registered to geospatial coordinates using either the photograph's GPS tags or a few ground control points across the scene. The system is ideally suited for studying ruptures of prehistoric, historic, and modern earthquakes in areas of sparse or low-lying vegetation. We use two sites from southern California faults to illustrate. The first is the ~0.1 km2 Washington Street site, located on the Banning strand of the San Andreas fault near Thousand Palms. A high-resolution DEM with ~700 point/m2 was produced from 230 photos collected on a balloon platform flying at 50 m above the ground. The second site is the Galway Lake Road site, which spans a ~1 km strip of the 1992 Mw 7.3 Landers earthquake on the Emerson Fault. The 100 point/m2 DEM was produced from 267 photos taken with a balloon platform at a height of 60 m above the ground

  2. Fault Tolerant Feedback Control

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, H.


    An architecture for fault tolerant feedback controllers based on the Youla parameterization is suggested. It is shown that the Youla parameterization will give a residual vector directly in connection with the fault diagnosis part of the fault tolerant feedback controller. It turns out that there...

  3. Performance based fault diagnosis

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik


    Different aspects of fault detection and fault isolation in closed-loop systems are considered. It is shown that using the standard setup known from feedback control, it is possible to formulate fault diagnosis problems based on a performance index in this general standard setup. It is also shown...

  4. New High-Resolution 3D Seismic Imagery of Deformation and Fault Architecture Along Newport-Inglewood/Rose Canyon Fault in the Inner California Borderlands (United States)

    Holmes, J. J.; Bormann, J. M.; Driscoll, N. W.; Kent, G.; Harding, A. J.; Wesnousky, S. G.


    The tectonic deformation and geomorphology of the Inner California Borderlands (ICB) records the transition from a convergent plate margin to a predominantly dextral strike-slip system. Geodetic measurements of plate boundary deformation onshore indicate that approximately 15%, or 6-8 mm/yr, of the total Pacific-North American relative plate motion is accommodated by faults offshore. The largest near-shore fault system, the Newport-Inglewood/Rose Canyon (NI/RC) fault complex, has a Holocene slip rate estimate of 1.5-2.0 mm/yr, according to onshore trenching, and current models suggest the potential to produce an Mw 7.0+ earthquake. The fault zone extends approximately 120 km, initiating from the south near downtown San Diego and striking northwards with a constraining bend north of Mt. Soledad in La Jolla and continuing northwestward along the continental shelf, eventually stepping onshore at Newport Beach, California. In late 2013, we completed the first high-resolution 3D seismic survey (3.125 m bins) of the NI/RC fault offshore of San Onofre as part of the Southern California Regional Fault Mapping project. We present new constraints on fault geometry and segmentation of the fault system that may play a role in limiting the extent of future earthquake ruptures. In addition, slip rate estimates using piercing points such as offset channels will be explored. These new observations will allow us to investigate recent deformation and strain transfer along the NI/RC fault system.

  5. Information Based Fault Diagnosis

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad


    Fault detection and isolation, (FDI) of parametric faults in dynamic systems will be considered in this paper. An active fault diagnosis (AFD) approach is applied. The fault diagnosis will be investigated with respect to different information levels from the external inputs to the systems....... These inputs are disturbance inputs, reference inputs and auxilary inputs. The diagnosis of the system is derived by an evaluation of the signature from the inputs in the residual outputs. The changes of the signatures form the external inputs are used for detection and isolation of the parametric faults....

  6. Fault isolability conditions for linear systems with additive faults

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob


    In this paper, we shall show that an unlimited number of additive single faults can be isolated under mild conditions if a general isolation scheme is applied. Multiple faults are also covered. The approach is algebraic and is based on a set representation of faults, where all faults within a set...... can occur simultaneously, whereas faults belonging to different fault sets appear disjoint in time. The proposed fault detection and isolation (FDI) scheme consists of three steps. A fault detection (FD) step is followed by a fault set isolation (FSI) step. Here the fault set is isolated wherein...... the faults have occurred. The last step is a fault isolation (FI) of the faults occurring in a specific fault set, i.e. equivalent with the standard FI step....

  7. October 1989 Loma Prieta, USA Images (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The magnitude 7.1 earthquake occurred near Loma Prieta in the Santa Cruz mountains. Movement occurred along a 40-km segment of the San Andreas fault from southwest...

  8. [Legitimation of Andries Van Wesele, Andreas Vesalius's father, by the Holy Roman Emperor Charles the Fifth]. (United States)

    Izumi, Hyonosuke


    Andries van Wesele, Andreas Vesalius's father and a court pharmacist of the Holy Roman Emperor Charles the fifth, was an illegitimate son of Everard van Wesele, a court physician of the Hapsburgs. In the year of 1531, Andries was legitimated by the Emperor. The legitimation letter was written in French. The author tried to translate and analyze the letter. By this legitimation, not only Andries himself was legitimated but also his successors were approved to succeed Andries. By this letter, Andreas Vesalius obtained his position as a hereditary member of a family serving the court of the Hapsburgs, and as a result, he started his career as a physician of the court.

  9. Evolution of the Puente Hills Thrust Fault (United States)

    Bergen, K. J.; Shaw, J. H.; Dolan, J. F.


    This study aims to assess the evolution of the blind Puente Hills thrust fault system (PHT) by determining its age of initiation, lateral propagation history, and changes in slip rate over time. The PHT presents one of the largest seismic hazards in the United States, given its location beneath downtown Los Angeles. The PHT is comprised of three fault segments: the Los Angeles (LA), Santa Fe Springs (SFS), and Coyote Hills (CH). The LA and SFS segments are characterized by growth stratigraphy where folds formed by uplift on the fault segments have been continually buried by sediment from the Los Angeles and San Gabriel rivers. The CH segment has developed topography and is characterized by onlapping growth stratigraphy. This depositional setting gives us the unique opportunity to measure uplift on the LA and SFS fault segments, and minimum uplift on the CH fault segment, as the difference in sediment thicknesses across the buried folds. We utilize depth converted oil industry seismic reflection data to image the fold geometries. Identifying time-correlative stratigraphic markers for slip rate determination in the basin has been a problem for researchers in the past, however, as the faunal assemblages observed in wells are time-transgressive by nature. To overcome this, we utilize the sequence stratigraphic model and well picks of Ponti et al. (2007) as a basis for mapping time-correlative sequence boundaries throughout our industry seismic reflection data from the present to the Pleistocene. From the Pleistocene to Miocene we identify additional sequence boundaries in our seismic reflection data from imaged sequence geometries and by correlating industry well formation tops. The sequence and formation top picks are then used to build 3-dimensional surfaces in the modeling program Gocad. From these surfaces we measure the change in thicknesses across the folds to obtain uplift rates between each sequence boundary. Our results show three distinct phases of

  10. Surficial geologic map of the Cuddeback Lake 30' x 60' quadrangle, San Bernardino and Kern counties, California (United States)

    Amoroso, Lee; Miller, David M.


    The 1:100,000-scale Cuddeback Lake quadrangle is located in the western Mojave Desert north-northeast of Los Angeles, between the southern Sierra Nevada and San Bernardino Mountains, in Kern and San Bernardino Counties, California. Geomorphic features include high-relief mountains, small hills, volcanic domes, pediments, broad alluvial valleys, and dry lakes. It is one in a series of surficial geologic maps created to investigate landscape development and tectonic evolution of the northern Mojave Desert. The mapped area includes pre-Tertiary plutonic, metavolcanic, metasedimentary, and igneous rocks; Tertiary sedimentary and volcanic rocks; and Quaternary sediments and basalts. The map area includes the El Paso, Lockhart, Blackwater, and Muroc Faults, as well as the central segment of the Garlock Fault Zone. The tectonically active western Mojave Desert and the variety of surficial materials have resulted in distinctive geomorphic features and terrains. Geologic mapping shows that active faults are widespread and have diverted drainage patterns. The tectonically active area near the Garlock Fault Zone and the nearby El Paso Fault influenced development of drainage networks; base level is controlled by fault offset. Evidence of a late Tertiary drainage network is preserved in remnants of alluvial fans and paleodrainage deposits north of the El Paso Mountains, west of the Lava Mountains, and south and west of the Rand Mountains. Holocene fault activity for the Cantil Valley, Lockhart, Garlock, and Rand Mountain Faults is indicated by displaced stream channels, playa-filled depressions, scarps, and shutter ridges. Previously unmapped Holocene and Late Pleistocene fault strands identified near the Rand Mountains may represent a splay at the northwest termination of the Lockhart Fault. The Grass Valley Fault, northwest of Black Mountain, is a right-lateral, strike-slip fault that may be a splay of the Blackwater Fault. Holocene activity on the Grass Valley Fault is

  11. Andreas Vesalius on the anatomy and function of the lower thoracic vertebrae. (United States)

    Biesbrouck, Maurits; Vanden Berghe, Alex


    Some remarkable statements made by Andreas Vesalius (1514-1564) in his principal work De Humani Corporis Fabrica (1543) about the anatomy and function of the lower thoracic vertebrae are discussed in the light of information from the literature. Their accuracy is evaluated on the basis of several pieces of anatomical evidence and clinical cases.

  12. Kunagi nii popp idabloki kadunud filmikunst / Eva Näripea, Andreas Trossek ; intervjueerinud Ave Randviir

    Index Scriptorium Estoniae

    Näripea, Eva


    2007. a. oktoobris toimunud konverentsi "Via Transversa : Lost Cinema of the Former Eastern Bloc" ettekannetel põhinevast kogumikust: Via Transversa : Lost Cinema of the Former Eastern Bloc / editors Eva Näripea, Andreas Trossek. Tallinn : Eesti Kunstiakadeemia, 2008. (Koht ja paik ; 7)

  13. Andrea Dworkin's "Mercy": Pain, Ad Personam, and Silence in the "War Zone." (United States)

    Eberly, Rosa A.


    Studies the public responses to Andrea Dworkin's novel "Mercy" (about rape specifically and the sexual abuse of women in general). Suggests that Dworkin's "Mercy"--like other controversial cultural texts--fostered a type of literary public sphere and that defining these spheres as "war zones" does not foster open debate or a common space for…

  14. Andreas Vesalius and the Occo medals of Augsburg. Evidence of a professional friendship. (United States)

    Houtzager, H L


    The friendly connection that existed between Andreas Vesalius (1514-1564) and his learned friends in Augsburg comprised three periods in the life of the emperor's court physician. The close ties that must have connected Adolphus Occo II and III and Vesalius are expressed in a number of medals carrying their images.

  15. SAN CARLOS APACHE PAPERS. (United States)



  16. Uncovering dynamic fault trees

    NARCIS (Netherlands)

    Junges, Sebastian; Guck, Dennis; Katoen, Joost P.; Stoelinga, Mariëlle Ida Antoinette

    Fault tree analysis is a widespread industry standard for assessing system reliability. Standard (static) fault trees model the failure behaviour of systems in dependence of their component failures. To overcome their limited expressive power, common dependability patterns, such as spare management,

  17. Fault Tolerant Control Systems

    DEFF Research Database (Denmark)

    Bøgh, S.A.

    failures. It is often feasible to increase availability for these control loops by designing the control system to perform on-line detection and reconfiguration in case of faults before the safety system makes a close-down of the process. A general development methodology is given in the thesis......This thesis considered the development of fault tolerant control systems. The focus was on the category of automated processes that do not necessarily comprise a high number of identical sensors and actuators to maintain safe operation, but still have a potential for improving immunity to component...... that carried the control system designer through the steps necessary to consider fault handling in an early design phase. It was shown how an existing control loop with interface to the plant wide control system could be extended with three additional modules to obtain fault tolerance: Fault detection...

  18. Solar system fault detection (United States)

    Farrington, R.B.; Pruett, J.C. Jr.


    A fault detecting apparatus and method are provided for use with an active solar system. The apparatus provides an indication as to whether one or more predetermined faults have occurred in the solar system. The apparatus includes a plurality of sensors, each sensor being used in determining whether a predetermined condition is present. The outputs of the sensors are combined in a pre-established manner in accordance with the kind of predetermined faults to be detected. Indicators communicate with the outputs generated by combining the sensor outputs to give the user of the solar system and the apparatus an indication as to whether a predetermined fault has occurred. Upon detection and indication of any predetermined fault, the user can take appropriate corrective action so that the overall reliability and efficiency of the active solar system are increased.

  19. Evaluating the potential for catastrophic fault-rupture-related hazards affecting a key hydroelectric and irrigation region in central Asia (United States)

    Rust, D.; Korjenkov, A.; Tibaldi, A.; Usmanova, M.


    The Toktogul hydroelectric and irrigation scheme is the largest in central Asia, with a reservoir containing almost 20 km3 of water behind a 230 m-high dam. Annually, the scheme generates 1200 MW of electricity that is distributed over Kyrgyzstan, Uzbekistan, Tajikistan, Kazakhstan and Russia. The scheme is vital for the economic, social and agricultural stability and development of the emerging central Asian republics it serves and, since it is no longer administered centrally as it was in Soviet times, is increasingly the focus of cross-border tensions involving competing needs for irrigation water and power supplies. Our work aims to identify and evaluate potential geo-environmental threats to this region for the benefit of stakeholders; with recommendations for measures to mitigate a range of threat scenarios, presented in a user-friendly GIS format. Most notably these scenarios involve the potential for very large magnitude earthquakes, with associated widespread slope instability, occurring on the little known Talas - Fergana fault. This structure, some 700 km long, bisects the Toktogul region within the actively (~20 mm a-1) contracting Tien Shan mountain range and exhibits geological characteristics similar to large strike-slip faults such as the San Andreas. Historical records are limited in this inaccessible mountainous region that, until Soviet times, was occupied by mainly nomadic peoples, but do not indicate recent fault rupture. This highlights the role of geological investigations in assembling a record of past catastrophic events to serve as a guide for what may be expected in the future, as well as the inherent difficulties in attempting geological forecasts to a precision that is useful on human timescales. Such forecasts in this region must also include the presence of some 23 uranium mining waste dumps within the mountain valleys, a legacy from Soviet times, as well as arsenic-rich waste dumps remaining from an earlier era of gold mining. Many

  20. Surficial Geologic Map and Geodatabase of the Cuddeback Lake 30' x 60' Quadrangle, San Bernardino and Kern Counties, California (United States)

    Amoroso, Lee; Miller, David M.


    A USGS surficial geologic mapping project, focused on the arid Southwest USA, conducted mapping and process studies to investigate landscape development and tectonic evolution. This project included the Cuddeback Lake 1:100,000-scale quadrangle located in the western Mojave Desert north-northeast of Los Angeles, between the southern Sierra Nevada and San Bernardino Mountains, in Kern and San Bernardino Counties, California. Geomorphic features include high-relief mountains, small hills, volcanic domes, pediments, broad alluvial valleys, and dry lakes. The mapped area includes pre-Tertiary plutonic, metavolcanic, metasedimentary, and other metamorphic rocks; Tertiary sedimentary and volcanic rocks; and Quaternary sediments and basalts. Included in the area are the El Paso, Lockhart, Blackwater, and Muroc faults as well as the central segment of the Garlock fault zone. The tectonically active western Mojave Desert and the variety of surficial materials have resulted in distinctive geomorphic features and terrains. Mapping has shown that the tectonically active area near the Garlock fault zone and El Paso Fault influenced development of drainage networks; base level is controlled by fault offset. There is evidence of a late Tertiary drainage network preserved in remnants of alluvial fans and paleo-drainage deposits north of the El Paso Mountains, west of the Lava Mountains, and south and west of the Rand Mountains. Faults identified as being active in the Holocene based on displaced stream channels, scarps, and shutter ridges include the Cantil Valley, Lockhart, Garlock, and Rand Mountain faults. Previously unmapped Holocene and late Pleistocene fault strands identified near the Rand Mountains may represent a splay at the northwest termination of the Lockhart Fault. The informally named Grass Valley fault, NW of Black Mountain, is a right-lateral strike-slip fault that may be a splay of the Blackwater Fault. Holocene activity on the Grass Valley fault is indicated by

  1. Fault Locating, Prediction and Protection (FLPPS)

    Energy Technology Data Exchange (ETDEWEB)

    Yinger, Robert, J.; Venkata, S., S.; Centeno, Virgilio


    One of the main objectives of this DOE-sponsored project was to reduce customer outage time. Fault location, prediction, and protection are the most important aspects of fault management for the reduction of outage time. In the past most of the research and development on power system faults in these areas has focused on transmission systems, and it is not until recently with deregulation and competition that research on power system faults has begun to focus on the unique aspects of distribution systems. This project was planned with three Phases, approximately one year per phase. The first phase of the project involved an assessment of the state-of-the-art in fault location, prediction, and detection as well as the design, lab testing, and field installation of the advanced protection system on the SCE Circuit of the Future located north of San Bernardino, CA. The new feeder automation scheme, with vacuum fault interrupters, will limit the number of customers affected by the fault. Depending on the fault location, the substation breaker might not even trip. Through the use of fast communications (fiber) the fault locations can be determined and the proper fault interrupting switches opened automatically. With knowledge of circuit loadings at the time of the fault, ties to other circuits can be closed automatically to restore all customers except the faulted section. This new automation scheme limits outage time and increases reliability for customers. The second phase of the project involved the selection, modeling, testing and installation of a fault current limiter on the Circuit of the Future. While this project did not pay for the installation and testing of the fault current limiter, it did perform the evaluation of the fault current limiter and its impacts on the protection system of the Circuit of the Future. After investigation of several fault current limiters, the Zenergy superconducting, saturable core fault current limiter was selected for

  2. Active faulting in the Inner California Borderlands: new constraints from high-resolution multichannel seismic and multibeam bathymetric data. (United States)

    Bormann, J. M.; Holmes, J. J.; Sahakian, V. J.; Klotsko, S.; Kent, G.; Driscoll, N. W.; Harding, A. J.; Wesnousky, S. G.


    Geodetic data indicate that faults offshore of Southern California accommodate 6-8 mm/yr of dextral Pacific-North American relative plate motion. In the Inner California Borderlands (ICB), modern strike-slip deformation is overprinted on topography formed during plate boundary reorganization 30-15 Ma. Despite its proximity to urban Southern California, the hazard posed by active faults in the ICB remains poorly understood. We acquired a 4000-line-km regional grid of high-resolution, 2D multichannel seismic (MCS) reflection data and multibeam bathymetry to examine the fault architecture and tectonic evolution of the ICB. We interpret the MCS data using a sequence stratigraphic approach to establish a chronostratigraphy and identify discrete episodes of deformation. We present our results in a regional fault model that distinguishes active deformation from older structures. Significant differences exist between our model of ICB deformation and existing models. Mounting evidence suggests a westward temporal migration of slip between faults in the ICB. In the eastern ICB, slip on the Newport-Inglewood/Rose Canyon fault and the neighboring Coronado Bank fault (CBF) diminishes to the north and appears to decrease over time. Undeformed Late Pliocene sediments overlie the northern extent of the CBF and the breakaway zone of the purported Oceanside Blind Thrust. Therefore, CBF slip rate estimates based on linkage with the Palos Verdes fault to the north are unwarranted. Deformation along the San Mateo, San Onofre, and Carlsbad trends is best explained as localized deformation resulting from geometrical complexities in a dextral strike-slip fault system. In the western ICB, the San Diego Trough fault (SDTF) offsets young sediments between the US/Mexico border and the eastern margin of Avalon Knoll, where the fault is spatially coincident with the San Pedro Basin fault (SPBF). Farther west, the San Clemente fault (SCF) has a strong linear bathymetric expression. The length

  3. Fault Management Metrics (United States)

    Johnson, Stephen B.; Ghoshal, Sudipto; Haste, Deepak; Moore, Craig


    This paper describes the theory and considerations in the application of metrics to measure the effectiveness of fault management. Fault management refers here to the operational aspect of system health management, and as such is considered as a meta-control loop that operates to preserve or maximize the system's ability to achieve its goals in the face of current or prospective failure. As a suite of control loops, the metrics to estimate and measure the effectiveness of fault management are similar to those of classical control loops in being divided into two major classes: state estimation, and state control. State estimation metrics can be classified into lower-level subdivisions for detection coverage, detection effectiveness, fault isolation and fault identification (diagnostics), and failure prognosis. State control metrics can be classified into response determination effectiveness and response effectiveness. These metrics are applied to each and every fault management control loop in the system, for each failure to which they apply, and probabilistically summed to determine the effectiveness of these fault management control loops to preserve the relevant system goals that they are intended to protect.

  4. Fault-tolerant design

    CERN Document Server

    Dubrova, Elena


    This textbook serves as an introduction to fault-tolerance, intended for upper-division undergraduate students, graduate-level students and practicing engineers in need of an overview of the field.  Readers will develop skills in modeling and evaluating fault-tolerant architectures in terms of reliability, availability and safety.  They will gain a thorough understanding of fault tolerant computers, including both the theory of how to design and evaluate them and the practical knowledge of achieving fault-tolerance in electronic, communication and software systems.  Coverage includes fault-tolerance techniques through hardware, software, information and time redundancy.  The content is designed to be highly accessible, including numerous examples and exercises.  Solutions and powerpoint slides are available for instructors.   ·         Provides textbook coverage of the fundamental concepts of fault-tolerance; ·         Describes a variety of basic techniques for achieving fault-toleran...

  5. Fault tolerant control for uncertain systems with parametric faults

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad


    A fault tolerant control (FTC) architecture based on active fault diagnosis (AFD) and the YJBK (Youla, Jarb, Bongiorno and Kucera)parameterization is applied in this paper. Based on the FTC architecture, fault tolerant control of uncertain systems with slowly varying parametric faults...

  6. Active Strike-Slip Faulting in the Inner Continental Borderland, Southern California: Results From New High-Resolution Seismic Reflection Data (United States)

    Conrad, J. E.; Ryan, H. F.; Sliter, R. W.


    The inner Continental Borderland offshore of southern California accommodates about 7 mm/yr of slip between the North American and Pacific plates. Nearly half of this total has previously been thought to be taken up on the Palos Verdes (PV) and Coronado Bank (CB) fault zones, which have been modeled as a single, continuous fault zone in recent seismic hazard assessments for southern California. Although these faults lie roughly on strike with each other, a connection between these faults has not been clearly demonstrated. Newly acquired high-resolution seismic reflection data indicate that the PV fault terminates southwest of Lasuen Knoll in a horsetail splay that becomes progressively buried to the south. The lack of a connection between the PV and CB fault zones implies that a significant amount of slip must be taken up elsewhere in the inner Continental Borderland. Two other significant offshore faults, the San Diego Trough (SDT) and San Pedro Basin (SPB) fault zones, lie about 10-15 km southwest of and sub parallel to the trace of the PV and CB faults. The SDT fault zone extends from south of the Mexican border near Punta Santo Tomas for about 150 km northward to near Crespi Knoll. The SPB fault zone extends northward from off Santa Catalina Island to near Point Dume. The new seismic reflection data reveal a previously unmapped but apparently active fault zone along strike and in the area between the known strands of the SDT and the SPB fault zones. This newly recognized fault links the SDT and SPB faults, forming a continuous, active fault zone that extends about 250 km along the inner Continental Borderland. Although there are no slip rate data available for this fault zone, its overall length, continuity, and active character suggest that a significant portion of the plate motion that occurs offshore is accommodated along the SDT-SPB fault zone, which may pose a more significant seismic hazard than previously recognized.

  7. Fault Analysis in Cryptography

    CERN Document Server

    Joye, Marc


    In the 1970s researchers noticed that radioactive particles produced by elements naturally present in packaging material could cause bits to flip in sensitive areas of electronic chips. Research into the effect of cosmic rays on semiconductors, an area of particular interest in the aerospace industry, led to methods of hardening electronic devices designed for harsh environments. Ultimately various mechanisms for fault creation and propagation were discovered, and in particular it was noted that many cryptographic algorithms succumb to so-called fault attacks. Preventing fault attacks without

  8. 19. IV avati Y-galeriis Andreas W kureeritud näitus "Puudumise kohalolu : the presence of absence"

    Index Scriptorium Estoniae


    Osalevad kunstnikud Kaisa Eiche, Toomas Kalve, Alan Proosa, Maari Ross, Riho Peiker, Anna Hints, Siim Vahur, Katz, Alan Ross, Jaan Sokk, Andreas W, Taavi Piibemann ja Kalev Vapper on Tartu Kõrgemast Kunstikoolist või sellega seotud

  9. Quaternary Fault Lines (United States)

    Department of Homeland Security — This data set contains locations and information on faults and associated folds in the United States that are believed to be sources of M>6 earthquakes during the...

  10. No-fault compensation following adverse events attributed to vaccination: a review of international programmes/Indemnisation sans egard a la faute consecutive a des evenements negatifs lies a la vaccination: evaluation des programmes internationaux/Compensacion sin admision de responsabilidad tras las reacciones adversas atribuidas a la vacunacion: revision

    National Research Council Canada - National Science Library

    Looker, Clare; Kelly, Heath


    Programmes that provide no-fault compensation for an adverse event following vaccination have been implemented in 19 countries worldwide, the first in Germany in 1961 and the most recent in Hungary in 2005...

  11. Fault lubrication during earthquakes. (United States)

    Di Toro, G; Han, R; Hirose, T; De Paola, N; Nielsen, S; Mizoguchi, K; Ferri, F; Cocco, M; Shimamoto, T


    The determination of rock friction at seismic slip rates (about 1 m s(-1)) is of paramount importance in earthquake mechanics, as fault friction controls the stress drop, the mechanical work and the frictional heat generated during slip. Given the difficulty in determining friction by seismological methods, elucidating constraints are derived from experimental studies. Here we review a large set of published and unpublished experiments (∼300) performed in rotary shear apparatus at slip rates of 0.1-2.6 m s(-1). The experiments indicate a significant decrease in friction (of up to one order of magnitude), which we term fault lubrication, both for cohesive (silicate-built, quartz-built and carbonate-built) rocks and non-cohesive rocks (clay-rich, anhydrite, gypsum and dolomite gouges) typical of crustal seismogenic sources. The available mechanical work and the associated temperature rise in the slipping zone trigger a number of physicochemical processes (gelification, decarbonation and dehydration reactions, melting and so on) whose products are responsible for fault lubrication. The similarity between (1) experimental and natural fault products and (2) mechanical work measures resulting from these laboratory experiments and seismological estimates suggests that it is reasonable to extrapolate experimental data to conditions typical of earthquake nucleation depths (7-15 km). It seems that faults are lubricated during earthquakes, irrespective of the fault rock composition and of the specific weakening mechanism involved.

  12. ["... here I am entirely among patients now..": the psychoanalytical practice of Lou Andreas-Salomé]. (United States)

    Klemann, Manfred


    The aim of this article is to disprove the widespread prejudice depicting Andreas-Salomé merely as a femme fatale, or companion of a few famous contemporaries (Nietzsche, Rilke, and Freud), while suppressing her original intellectual and clinical-practical achievement as a psychoanalyst. An evaluation of both published and hitherto unpublished sources clearly confirms the broad and thorough foundations of her psychoanalytical training in theory as well as in practice. Between 1913 and 1933 Andreas-Salomé conducted a relatively large number of analyses, discussed some of them with Freud in a kind of "supervision" by correspondence and published several articles on central psychoanalytical issues. So far, however, many psychoanalysts seem to have been unaware of her status as a former accomplished colleague.

  13. 11th June 2009-Cyprus-Minister of Education and Culture H. E. Prof. Andreas Demetriou

    CERN Document Server

    Maximilien Brice


    Tirage 1 :CERN Director-General, R. Heuer and Minister of Education and Culture, H. E. Prof. Andreas Demetriou; Tirage 2:Council President,T. Åkesson, Ecole Normale Supérieure,K. Kounnas, Chairman of the Cyprus CERN Committee,C. N. Papanicolas, R. Heuer,A. Demetriou, Permanent Representative of the Republic of Cyprus in Geneva,A. Hadjichrysanthou, Directorate Office,E. Tsesmelis

  14. Minisparker seismic-reflection data of field activity S-5-09-SC: San Pedro Basin, offshore southern California from 2009-07-06 to 2009-07-10 (United States)

    Sliter, Ray W.; Conrad, James E.; Ryan, Holly F; Triezenberg, Peter


    This dataset includes raw and processed, high-resolution seismic-reflection data collected in 2009 to explore a possible connection between the San Diego Trough Fault and the San Pedro Basin Fault. The survey is in the San Pedro Basin between Santa Catalina Island and San Pedro, California. The data were collected aboard the U.S. Geological Survey R/V Parke Snavely. The seismic-reflection data were acquired using a SIG 2mille minisparker. Subbottom acoustic penetration spanned tens to several hundreds of meters, variable by location.

  15. Active Fault Isolation in MIMO Systems

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad


    isolation is based directly on the input/output s ignals applied for the fault detection. It is guaranteed that the fault group includes the fault that had occurred in the system. The second step is individual fault isolation in the fault group . Both types of isolation are obtained by applying dedicated......Active fault isolation of parametric faults in closed-loop MIMO system s are considered in this paper. The fault isolation consists of two steps. T he first step is group- wise fault isolation. Here, a group of faults is isolated from other pos sible faults in the system. The group-wise fault...

  16. Faults in Linux

    DEFF Research Database (Denmark)

    Palix, Nicolas Jean-Michel; Thomas, Gaël; Saha, Suman


    a major problem? To answer these questions, we have transported the experiments of Chou et al. to Linux versions 2.6.0 to 2.6.33, released between late 2003 and early 2010. We find that Linux has more than doubled in size during this period, but that the number of faults per line of code has been......In 2001, Chou et al. published a study of faults found by applying a static analyzer to Linux versions 1.0 through 2.4.1. A major result of their work was that the drivers directory contained up to 7 times more of certain kinds of faults than other directories. This result inspired a number...... decreasing. And, even though drivers still accounts for a large part of the kernel code and contains the most faults, its fault rate is now below that of other directories, such as arch (HAL) and fs (file systems). These results can guide further development and research efforts. To enable others...

  17. Investigations into early rift development and geothermal resources in the Pyramid Lake fault zone, Western Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Eisses, A.; Kell, A.; Kent, G.; Driscoll, N. [UCSD; Karlin, R.; Baskin, R. [USGS; Louie, J. [UNR; Pullammanappallil, S. [Optim


    A. K. Eisses, A. M. Kell, G. Kent, N. W. Driscoll, R. E. Karlin, R. L. Baskin, J. N. Louie, S. Pullammanappallil, 2010, Investigations into early rift development and geothermal resources in the Pyramid Lake fault zone, Western Nevada: Abstract T33C-2278 presented at 2010 Fall Meeting, AGU, San Francisco, Calif., 13-17 Dec.

  18. Fault Detection for Industrial Processes

    Directory of Open Access Journals (Sweden)

    Yingwei Zhang


    Full Text Available A new fault-relevant KPCA algorithm is proposed. Then the fault detection approach is proposed based on the fault-relevant KPCA algorithm. The proposed method further decomposes both the KPCA principal space and residual space into two subspaces. Compared with traditional statistical techniques, the fault subspace is separated based on the fault-relevant influence. This method can find fault-relevant principal directions and principal components of systematic subspace and residual subspace for process monitoring. The proposed monitoring approach is applied to Tennessee Eastman process and penicillin fermentation process. The simulation results show the effectiveness of the proposed method.

  19. What is Fault Tolerant Control

    DEFF Research Database (Denmark)

    Blanke, Mogens; Frei, C. W.; Kraus, K.


    availability and reduce the risk of safety hazards. Its aim is to prevent that simple faults develop into serious failure. Fault-tolerant control merges several disciplines to achieve this goal, including on-line fault diagnosis, automatic condition assessment and calculation of remedial actions when a fault......Faults in automated processes will often cause undesired reactions and shut-down of a controlled plant, and the consequences could be damage to the plant, to personnel or the environment. Fault-tolerant control is the synonym for a set of recent techniques that were developed to increase plant...

  20. Holocene Tectonic and Sedimentary Evolution of Coastal San Diego (United States)

    Maloney, J. M.; Driscoll, N. W.; Brothers, D. S.; Babcock, J. M.; Kent, G.


    The shelf and nearshore region of San Diego, California, between La Jolla cove in the north and the U.S.- Mexico border in the south, is an important ecological and economic resource. It contains two of the largest kelp forests in southern California and lies offshore miles of popular beaches. Understanding the interplay between tectonic and sedimentary processes in this area is critical because it will allow us to assess how other forcing functions such as the rapid sea level rise (2 - 3 mm/yr) and predicted climate change associated with global warming are impacting the kelp and nearshore environments. The fault architecture and sedimentary deposits offshore San Diego have been mapped using high-resolution seismic CHIRP profiling. The mapped area lies within the inner California Continental Borderland (CCB), which is characterized by a system of basins and ridges and extensive strike-slip faulting. The CHIRP data clearly images several splays of the Coronado Bank Fault Zone (CBFZ), a major fault in the area, which show recent activity in the upper 30 m of sediment with the most recent deformation at ~4 m below seafloor. Several sediment packages as deep as 50 m below the seafloor are imaged and place important constraints on tectonic deformation and sediment dispersal in the region as well as the earthquake recurrence interval on the CBFZ. Exposed and buried wavecut terraces identified on numerous CHIRP profiles, which can be correlated to terraces mapped regionally, provide insight into tectonic uplift rates and sea-level fluctuations. Finally, the extensive kelp forests offshore Mount Soledad and Point Loma occur where hardgrounds are exposed at the seafloor as a consequence of tectonic uplift. High resolution mapping offshore San Diego is providing new insight into the complex interplay between tectonics, sedimentation, and biology in this ecologically diverse region.

  1. Geomorphic evidence of Quaternary tectonics within an underlap fault zone of southern Apennines, Italy (United States)

    Giano, Salvatore Ivo; Pescatore, Eva; Agosta, Fabrizio; Prosser, Giacomo


    A composite seismic source, the Irpinia - Agri Valley Fault zone, located in the axial sector of the fold-and-thrust belt of southern Apennines, Italy, is investigated. This composite source is made up of a series of nearly parallel, NW-striking normal fault segments which caused many historical earthquakes. Two of these fault segments, known as the San Gregorio Magno and Pergola-Melandro, and the fault-related mountain fronts, form a wedge-shaped, right-stepping, underlap fault zone. This work is aimed at documenting tectonic geomorphology and geology of this underlap fault zone. The goal is to decipher the evidence of surface topographic interaction between two bounding fault segments and their related mountain fronts. In particular, computation of geomorphic indices such as mountain front sinuosity (Smf), water divide sinuosity (Swd), asymmetry factor (AF), drainage basin elongation (Bs), relief ratio (Rh), Hypsometry (HI), normalized steepness (Ksn), and concavity (θ) is integrated with geomorphological analysis, the geological mapping, and structural analysis in order to assess the recent activity of the fault scarp sets recognized within the underlap zone. Results are consistent with the NW-striking faults as those showing the most recent tectonic activity, as also suggested by presence of related slope deposits younger than 38 ka. The results of this work therefore show how the integration of a multidisciplinary approach that combines geomorphology, morphometry, and structural analyses may be key to solving tectonic geomorphology issues in a complex, fold-and-thrust belt configuration.

  2. Geologic and bayhymetric reconnaissance overview of the San Pedro Shelf Region, southern California (United States)

    Wolf, Stephen C.; Gutmacher, Christina E.


    This report presents a series of maps that describe the bathymetry and late Quaternary geology of the San Pedro shelf area as interpreted from seismic-reflection profiles and 3.5-kHz and multibeam bathymetric data. Some of the seismic-reflection profiles were collected with Uniboom and 120-kJ sparker during surveys conducted by the U.S. Geological Survey (USGS) in 1973 (K-2-73-SC), 1978 (S-2-78-SC), and 1979 (S-2a-79-SC). The remaining seismic-reflection profiles were collected in 2000 using Geopulse boomer and minisparker during USGS cruise A-1-00-SC. The report consists of seven oversized sheets: 1. Map of 1978 and 1979 uniboom seismic-reflection and 3.5-kHz tracklines used to map faults and folds on San Pedro Shelf. 2. Maps of multibeam shaded bathymetric relief with faults and folds, and bathymetric contours. 3. Isopach map of unconsolidated sediment, seismic-reflection profile across the San Pedro shelf, seismic-reflection profile across San Gabriel paleo-valley. 4. Seismic-reflection profiles across the Palos Verdes Fault Zone. 5. Geologic map and samples of Uniboom and 120-kJ sparker seismic-reflection profiles used to make the map. 6. Map showing thickness of uppermost (Holocene?) sediment layer. 7. Map of San Gabriel Canyon paleo-valley and associated drainage basins.

  3. Wind turbine fault detection and fault tolerant control

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Johnson, Kathryn


    In this updated edition of a previous wind turbine fault detection and fault tolerant control challenge, we present a more sophisticated wind turbine model and updated fault scenarios to enhance the realism of the challenge and therefore the value of the solutions. This paper describes...... the challenge model and the requirements for challenge participants. In addition, it motivates many of the faults by citing publications that give field data from wind turbine control tests....

  4. Constraining fault growth rates and fault evolution in New Zealand


    Lamarche, G.; Bull, J. M.; Barnes, P.M.; Taylor, S.K.; Horgan, H.


    Understanding how faults propagate, grow and interact in fault systems is important because they are primarily responsible for the distribution of strain in the upper crust. They localise deformation and stress release, often producing surface displacements that control sedimentation and fluid flow either by acting as conduits or barriers. Identifying fault spatial distribution, quantifying activity, evaluating linkage mechanism, and estimating fault growth rates are key components in seismic...

  5. Computer hardware fault administration (United States)

    Archer, Charles J.; Megerian, Mark G.; Ratterman, Joseph D.; Smith, Brian E.


    Computer hardware fault administration carried out in a parallel computer, where the parallel computer includes a plurality of compute nodes. The compute nodes are coupled for data communications by at least two independent data communications networks, where each data communications network includes data communications links connected to the compute nodes. Typical embodiments carry out hardware fault administration by identifying a location of a defective link in the first data communications network of the parallel computer and routing communications data around the defective link through the second data communications network of the parallel computer.

  6. Fault Tolerant Computer Architecture

    CERN Document Server

    Sorin, Daniel


    For many years, most computer architects have pursued one primary goal: performance. Architects have translated the ever-increasing abundance of ever-faster transistors provided by Moore's law into remarkable increases in performance. Recently, however, the bounty provided by Moore's law has been accompanied by several challenges that have arisen as devices have become smaller, including a decrease in dependability due to physical faults. In this book, we focus on the dependability challenge and the fault tolerance solutions that architects are developing to overcome it. The two main purposes

  7. Fault tolerant control based on active fault diagnosis

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik


    An active fault diagnosis (AFD) method will be considered in this paper in connection with a Fault Tolerant Control (FTC) architecture based on the YJBK parameterization of all stabilizing controllers. The architecture consists of a fault diagnosis (FD) part and a controller reconfiguration (CR) ...

  8. ESR dating of fault rocks

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee Kwon [Kangwon National Univ., Chuncheon (Korea, Republic of)


    Past movement on faults can be dated by measurement of the intensity of ESR signals in quartz. These signals are reset by local lattice deformation and local frictional heating on grain contacts at the time of fault movement. The ESR signals then trow back as a result of bombardment by ionizing radiation from surrounding rocks. The age is obtained from the ratio of the equivalent dose, needed to produce the observed signal, to the dose rate. Fine grains are more completely reset during faulting, and a plot of age vs grain size shows a plateau for grains below critical size : these grains are presumed to have been completely zeroed by the last fault activity. We carried out ESR dating of fault rocks collected from the Yangsan fault system. ESR dates from the this fault system range from 870 to 240 ka. Results of this research suggest that long-term cyclic fault activity continued into the pleistocene.

  9. Fault diagnosis of induction motors

    CERN Document Server

    Faiz, Jawad; Joksimović, Gojko


    This book is a comprehensive, structural approach to fault diagnosis strategy. The different fault types, signal processing techniques, and loss characterisation are addressed in the book. This is essential reading for work with induction motors for transportation and energy.

  10. Fault management and systems knowledge (United States)


    Pilots are asked to manage faults during flight operations. This leads to the training question of the type and depth of system knowledge required to respond to these faults. Based on discussions with multiple airline operators, there is agreement th...

  11. Improving Multiple Fault Diagnosability using Possible Conflicts (United States)

    National Aeronautics and Space Administration — Multiple fault diagnosis is a difficult problem for dynamic systems. Due to fault masking, compensation, and relative time of fault occurrence, multiple faults can...

  12. Normal Fault Growth on Mars (United States)

    Morris, A. P.; Wyrick, D. Y.; Ferrill, D. A.


    Displacement versus length relationships of faults on Earth and Mars have been used to describe and interpret the evolution of faults and fault systems, infer differences in the relative strengths of strata, and evaluate variations in fault-system response to differences in gravity from planet to planet. In this presentation, we focus on maximum throw versus trace length (Dmax/L) of continuously mappable faults and Dmax/L of individual fault segments. Fault analyses on Mars have the advantage of a planetary surface devoid of vegetation and largely unaffected by weathering and erosion. Areas on the flanks of Alba Patera, Mars, were chosen because they are well imaged by all generations of data coverage, contain fault systems that have a range of developmental characteristics, and formed in a relatively simple tectonic setting dominated by extension. Footwall and hanging wall cutoff traces of more than 300 faults were interpreted using Viking imagery and ArcGIS software. Throw was obtained by calculating the elevation difference between adjacent footwall and hanging wall points using Mars Orbiter Laser Altimeter data. Throw versus along-strike trace length plots were constructed for each interpreted fault. Single fault segments are defined as having one well-defined displacement maximum bounded by two near-zero displacement minima. Segments within a multi-segment fault were identified by counting displacement maxima along the fault trace. The number of segments incorporated into multi-segment faults is positively correlated with the fault trace length. In a plot of Dmax versus L, whole faults are distributed approximately along a locus of Dmax = K × Ln, where K = 5 × 10-4 to 5 × 10-2 and n = 1. This is in agreement with previous studies of faults on Mars. Single fault segments form a distinct population whose distribution is described approximately by the same equation but where K = 1.7 × 10-3. Dmax/L ratios for multi-segment faults represent an apparently self

  13. Seismic Slip on an Oblique Detachment Fault at Low Angles (United States)

    Janecke, S. U.; Steely, A. N.; Evans, J. P.


    Pseudotachylytes are one of the few accepted indicators of seismic slip along ancient faults. Low-angle normal faults have produced few large earthquakes in historic times and low-angle normal faults (detachment faults) are typically severely misoriented relative to a vertical maximum compressive stress. As a result many geoscientists question whether low-angle normal faults produce earthquakes at low angles. Relationships in southern California show that a major low-angle normal-oblique fault slipped at low angles and produced large earthquakes. The exhumed Late Cenozoic West Salton detachment fault preserves spectacular fault- related pseudotachylytes along its fault plane and injected into its hanging wall and footwall. Composite pseudotachylyte zones are up to 1.25 m thick and persists over lateral distances of at least 10's of meters. Pseudotachylyte is common in most thin sections of damaged fault rocks with more than 20% (by volume) of cataclasite. We recognized the presence of original melt using numerous criteria: abundant spherulites in thin sections, injection structures at both the thin-section and outcrop scale, black aphanitic textures, quenched vein margins, variations in microcrystallite textures and/or size with respect to the vein margin, and glassy textures in hand sample. Multiple earthquakes are inferred to produce the layered "stratigraphy" in some exposures of pseudotachylytes. We infer that the West Salton detachment fault formed and slipped at low angles because it nearly perfectly reactivates a Cretaceous ductile thrust system at the half km scale and dips between 10 and 45 degrees. The about 30 degree NNE dip of the detachment fault on the north side of Yaqui Ridge is likely steeper than its dip during detachment slip because there is local steepening on the flanks of the Yaqui Ridge antiform in a contractional stepover of a crosscutting Quaternary San Felipe dextral fault zone. These relationships indicate a low dip on the detachment

  14. Fault Tolerant Wind Farm Control

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob


    In the recent years the wind turbine industry has focused on optimizing the cost of energy. One of the important factors in this is to increase reliability of the wind turbines. Advanced fault detection, isolation and accommodation are important tools in this process. Clearly most faults are deal...... scenarios. This benchmark model is used in an international competition dealing with Wind Farm fault detection and isolation and fault tolerant control....

  15. The engine fuel system fault analysis (United States)

    Zhang, Yong; Song, Hanqiang; Yang, Changsheng; Zhao, Wei


    For improving the reliability of the engine fuel system, the typical fault factor of the engine fuel system was analyzed from the point view of structure and functional. The fault character was gotten by building the fuel system fault tree. According the utilizing of fault mode effect analysis method (FMEA), several factors of key component fuel regulator was obtained, which include the fault mode, the fault cause, and the fault influences. All of this made foundation for next development of fault diagnosis system.

  16. Formal fault tree semantics


    Schellhorn, Gerhard


    Formal fault tree semantics / G. Schellhorn, A. Thums, and W. Reif. - In: IDPT : Proceedings of the Sixth World Conference on Integrated Design and Process Technology : June 23 - 27, 2003, Pasadena, California / SDPS, Society for Design & Process Science. - 2002. - 1CD-ROM

  17. Diagnosing Intermittent Faults

    NARCIS (Netherlands)

    Van Gemund, A.J.C.; Abreu, R.F.; Zoeteweij, P.


    In this working report we outline how to determine the intermittency parameters gj from the activity matrix A (context: DX’08 paper Abreu, Zoeteweij, Van Gemund). We start with the single fault (SF) case and show that averaging over the error vector e is the exact way. We also show that in this way

  18. Network Power Fault Detection


    Siviero, Claudio


    Network power fault detection. At least one first network device is instructed to temporarily disconnect from a power supply path of a network, and at least one characteristic of the power supply path of the network is measured at a second network device connected to the network while the at least one first network device is temporarily disconnected from the network

  19. Detecting Faults from Encoded Information

    NARCIS (Netherlands)

    Persis, Claudio De


    The problem of fault detection for linear continuous-time systems via encoded information is considered. The encoded information is received at a remote location by the monitoring deiice and assessed to infer the occurrence of the fault. A class of faults is considered which allows to use a simple

  20. A revised estimate of Pacific-North America motion and implications for Western North America plate boundary zone tectonics (United States)

    Demets, Charles; Gordon, Richard G.; Stein, Seth; Argus, Donald F.


    Marine magnetic profiles from the Gulf of Californa are studied in order to revise the estimate of Pacific-North America motion. It is found that since 3 Ma spreading has averaged 48 mm/yr, consistent with a new global plate motion model derived without any data. The present data suggest that strike-slip motion on faults west of the San Andreas is less than previously thought, reducing the San Andreas discrepancy with geodetic, seismological, and other geologic observations.

  1. Fault-Related Sanctuaries (United States)

    Piccardi, L.


    Beyond the study of historical surface faulting events, this work investigates the possibility, in specific cases, of identifying pre-historical events whose memory survives in myths and legends. The myths of many famous sacred places of the ancient world contain relevant telluric references: "sacred" earthquakes, openings to the Underworld and/or chthonic dragons. Given the strong correspondence with local geological evidence, these myths may be considered as describing natural phenomena. It has been possible in this way to shed light on the geologic origin of famous myths (Piccardi, 1999, 2000 and 2001). Interdisciplinary researches reveal that the origin of several ancient sanctuaries may be linked in particular to peculiar geological phenomena observed on local active faults (like ground shaking and coseismic surface ruptures, gas and flames emissions, strong underground rumours). In many of these sanctuaries the sacred area is laid directly above the active fault. In a few cases, faulting has affected also the archaeological relics, right through the main temple (e.g. Delphi, Cnidus, Hierapolis of Phrygia). As such, the arrangement of the cult site and content of relative myths suggest that specific points along the trace of active faults have been noticed in the past and worshiped as special `sacred' places, most likely interpreted as Hades' Doors. The mythological stratification of most of these sanctuaries dates back to prehistory, and points to a common derivation from the cult of the Mother Goddess (the Lady of the Doors), which was largely widespread since at least 25000 BC. The cult itself was later reconverted into various different divinities, while the `sacred doors' of the Great Goddess and/or the dragons (offspring of Mother Earth and generally regarded as Keepers of the Doors) persisted in more recent mythologies. Piccardi L., 1999: The "Footprints" of the Archangel: Evidence of Early-Medieval Surface Faulting at Monte Sant'Angelo (Gargano, Italy

  2. 78 FR 58878 - Safety Zone; San Diego Shark Fest Swim; San Diego Bay, San Diego, CA (United States)


    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; San Diego Shark Fest Swim; San Diego Bay... Diego Shark Fest Swim. This safety zone is necessary to provide for the safety of the participants, crew... this rule because the logistical details of the San Diego Shark Fest Swim were not finalized nor...

  3. The Renaissance and the universal surgeon: Giovanni Andrea Della Croce, a master of traumatology. (United States)

    Di Matteo, Berardo; Tarabella, Vittorio; Filardo, Giuseppe; Viganò, Anna; Tomba, Patrizia; Marcacci, Maurilio


    All the medical knowledge of all time in one book, the universal and perfect manual for the Renaissance surgeon, and the man who wrote it. This paper depicts the life and works of Giovanni Andrea della Croce, a 16th Century physician and surgeon, who, endowed with true spirit of Renaissance humanism, wanted to teach and share all his medical knowledge through his opus magnum, titled "Universal Surgery Complete with All the Relevant Parts for the Optimum Surgeon". An extraordinary book which truly represents a defining moment and a founding stone for traumatology, written by a lesser known historical personality, but nonetheless the Renaissance Master of Traumatology.

  4. [The copy of De humani corporis fabrica of Andreas Vesalius of the municipal library of Reims]. (United States)

    Ségal, Alain


    The author presents a copy of the De humani corporis fabrica by Andreas Vesalius; this book is preserved in the department of rare books of the municipal Library in Reims. This copy is a first edition as the author gives positive proofs. This book results of a donation to the Minimes's congregation of Reims by Seigneur Guillaume Le Vergeur, Count of Saint Souplet and Baillif of Vermandois in the 17th century. Guillaume Le Vergeur has also given other precious books to the monastery's library and his name is inscribed on the register of obituaries and on the pediment of the Minimes' Church.

  5. Comment on ``Dynamical Implications of Block Averaging'' by G. Treviño and E.L Andreas (United States)

    Eckman, Richard M.


    A 2006 article in Boundary-Layer Meteorology by G. Treviño and E.L Andreas presents a derivation that questions the use of time averaging for computing turbulence statistics. Their derivation shows that time averaging over a finite interval always leads to a zero integral time scale. As a result, Treviño and Andreas argue that any turbulence quantities derived from time averaging are tainted and incompatible with the Navier Stokes equations. While Treviño and Andreas are correct that time averaging does produce integral scales that are quite different from what researchers commonly expect, this comment demonstrates that the theoretical implications are not as dire as they claim.

  6. Structural and geochemical characteristics of faulted sediments and inferences on the role of water in deformatiion, Rio Grande Rift, New Mexico (United States)

    Caine, Jonathan S.; Minor, S.A.


    The San Ysidro fault is a spectacularly exposed normal fault located in the northwestern Albuquerque Basin of the Rio Grande Rift. This intrabasin fault is representative of many faults that formed in poorly lithified sediments throughout the rift. The fault is exposed over nearly 10 km and accommodates nearly 700 m of dip slip in subhorizontal, siliciclastic sediments. The extent of the exposure facilitates study of along-strike variations in deformation mechanisms, archi tecture, geochemistry, and permeability. The fault is composed of structural and hydrogeologic components that include a clay-rich fault core, a calcite-cemented mixed zone, and a poorly developed damage zone primarily consisting of deformation bands. Structural textures suggest that initial deformation in the fault occurred at low temperature and pressure, was within the paleosaturated zone of the evolving Rio Grande Rift, and was dominated by particulate flow. Little geochemical change is apparent across the fault zone other than due to secondary processes. The lack of fault-related geochemical change is interpreted to reflect the fundamental nature of water-saturated, particulate fl ow. Early mechanical entrainment of low-permeability clays into the fault core likely caused damming of groundwater flow on the up-gradient, footwall side of the fault. This may have caused a pressure gradient and flow of calcite-saturated waters in higher-permeability, fault-entrained siliciclastic sediments, ultimately promoting their cementation by sparry calcite. Once developed, the cemented and clay-rich fault has likely been, and continues to be, a partial barrier to cross-fault groundwater flow, as suggested by petrophysical measurements. Aeromagnetic data indicate that there may be many more unmapped faults with similar lengths to the San Ysidro fault buried within Rio Grande basins. If these buried faults formed by the same processes that formed the San Ysidro fault and have persistent low

  7. Fault linkage and continental breakup (United States)

    Cresswell, Derren; Lymer, Gaël; Reston, Tim; Stevenson, Carl; Bull, Jonathan; Sawyer, Dale; Morgan, Julia


    The magma-poor rifted margin off the west coast of Galicia (NW Spain) has provided some of the key observations in the development of models describing the final stages of rifting and continental breakup. In 2013, we collected a 68 x 20 km 3D seismic survey across the Galicia margin, NE Atlantic. Processing through to 3D Pre-stack Time Migration (12.5 m bin-size) and 3D depth conversion reveals the key structures, including an underlying detachment fault (the S detachment), and the intra-block and inter-block faults. These data reveal multiple phases of faulting, which overlap spatially and temporally, have thinned the crust to between zero and a few km thickness, producing 'basement windows' where crustal basement has been completely pulled apart and sediments lie directly on the mantle. Two approximately N-S trending fault systems are observed: 1) a margin proximal system of two linked faults that are the upward extension (breakaway faults) of the S; in the south they form one surface that splays northward to form two faults with an intervening fault block. These faults were thus demonstrably active at one time rather than sequentially. 2) An oceanward relay structure that shows clear along strike linkage. Faults within the relay trend NE-SW and heavily dissect the basement. The main block bounding faults can be traced from the S detachment through the basement into, and heavily deforming, the syn-rift sediments where they die out, suggesting that the faults propagated up from the S detachment surface. Analysis of the fault heaves and associated maps at different structural levels show complementary fault systems. The pattern of faulting suggests a variation in main tectonic transport direction moving oceanward. This might be interpreted as a temporal change during sequential faulting, however the transfer of extension between faults and the lateral variability of fault blocks suggests that many of the faults across the 3D volume were active at least in part

  8. Combined UAVSAR and GPS Estimates of Fault Slip for the M 6.0 South Napa Earthquake (United States)

    Donnellan, A.; Parker, J. W.; Hawkins, B.; Hensley, S.; Jones, C. E.; Owen, S. E.; Moore, A. W.; Wang, J.; Pierce, M. E.; Rundle, J. B.


    Combined UAVSAR and GPS Estimates of Fault Slip for the M 6.0 South Napa Earthquake Andrea Donnellan, Jay Parker, Brian Hawkins, Scott Hensley, Cathleen Jones, Susan Owen, Angelyn Moore Jet Propulsion Laboratory, California Institute of Technology Marlon Pierce, Jun Wang Indiana University John Rundle University of California, Davis The South Napa to Santa Rosa area has been observed with NASA's UAVSAR since late 2009 as part of an experiment to monitor areas identified as having a high probability of an earthquake. The M 6.0 South Napa earthquake occurred on 24 August 2014. The area was flown 29 May 2014 preceeding the earthquake, and again on 29 August 2014, five days after the earthquake. The UAVSAR results show slip on a single fault at the south end of the rupture near the epicenter of the event. The rupture branches out into multiple faults further north near the Napa area. A combined inversion of rapid GPS results and the unwrapped UAVSAR interferogram indicate nearly pure strike slip motion. Using this assumption, the UAVSAR data show horizontal right-lateral slip across the fault of 19 cm at the south end of the rupture and increasing to 70 cm northward over a distance of 6.5 km. The joint inversion indicates slip of ~30 cm on a network of sub-parallel faults is concentrated in a zone about 17 km long. The lower depths of the faults are 5-8.5 km. The eastern two sub-parallel faults break the surface, while three faults to the west are buried at depths ranging from 2-6 km with deeper depths to the north and west. The geodetic moment release is equivalent to a M 6.1 event. Additional ruptures are observed in the interferogram, but the inversions suggest that they represent superficial slip that does not contribute to the overall moment release.

  9. Andreas Vesalius 500 years--A Renaissance that revolutionized cardiovascular knowledge. (United States)

    Mesquita, Evandro Tinoco; Souza Júnior, Celso Vale de; Ferreira, Thiago Reigado


    The history of medicine and cardiology is marked by some geniuses who dared in thinking, research, teaching and transmitting scientific knowledge, and the Italian Andreas Vesalius one of these brilliant masters. His main scientific work "De Humani Corporis Fabrica" is not only a landmark study of human anatomy but also an artistic work of high aesthetic quality published in 1543. In the year 2014 we celebrated 500 years since the birth of the brilliant professor of Padua University, who with his courage and sense of observation changed the understanding of cardiovascular anatomy and founded a school to date in innovative education and research of anatomy. By identifying "the anatomical errors" present in Galen's book and speech, he challenged the dogmas of the Catholic Church, the academic world and the doctors of his time. However, the accuracy of his findings and his innovative way to disseminate them among his students and colleagues was essential so that his contributions are considered by many the landmark of modern medicine. His death is still surrounded by mysteries having different hypotheses, but a certainty, suffered sanctions of the Catholic Church for the spread of their ideas. The cardiologists, cardiovascular surgeons, interventional cardiologists, electrophysiologists and cardiovascular imaginologists must know the legacy of genius Andreas Vesalius that changed the paradigm of human anatomy.

  10. Structural geometry and gravity constraints on the Palos Verdes and Cabrillo faults (United States)

    Cengelcik, Yeliz

    The thesis presents and evaluates five new gravity constrained structural cross-sections about the Palos Verdes and Cabrillo faults of southern California. They both have been active since the Miocene, however the Palos Verdes fault zone is considered to be a greater seismic hazard. Using geologic, gravity and seismic data we present new interpretations about the geometry of the Palos Verdes and Cabrillo faults. In the San Pedro and Los Angeles Harbor region approximately125 new gravity data were collected with a Worden gravimeter and new structural cross-sections were constructed by using data of our gravity surveying. The collected data displays a Simple Bouguer gravity anomaly high near the Cabrillo fault and northwards toward the Palos Verdes fault there is an approximately 30 mGal decrease. The Palos Verdes fault itself is characterized by an inflection in the gravity data and a relatively flat zone immediately to the north. This shelf in the gravity data is important because the highly productive Wilmington Oil Field is located in this area and it is likely a product of the particular geometry in the region. The Palos Verdes fault also forms the edge of the larger Los Angeles Basin. Our basic interpretation is that the Palos Verdes and Cabrillo faults are primarily strike slip faults. However, a horst-like block between the two faults has been uplifted and horizontally shortened. Our main interpretation is that Catalina Schist basement uplift and subsequent basin fill to the north is responsible for the large negative gravity anomalies associated with the Palos Verdes fault.

  11. 75 FR 55975 - Safety Zone; San Diego Harbor Shark Fest Swim; San Diego Bay, San Diego, CA (United States)


    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; San Diego Harbor Shark Fest Swim; San Diego... Shark Fest Swim, consisting of 600 swimmers swimming a predetermined course. The sponsor will provide 26...; San Diego Harbor Shark Fest Swim; San Diego Bay, San Diego, CA. (a) Location. The following area is a...

  12. ESR dating of fault rocks

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee Kwon [Kangwon National Univ., Chuncheon (Korea, Republic of)


    Past movement on faults can be dated by measurement of the intensity of ESR signals in quartz. These signals are reset by local lattice deformation and local frictional heating on grain contacts at the time of fault movement. The ESR signals then grow back as a result of bombardment by ionizing radiation from surrounding rocks. The age is obtained from the ratio of the equivalent dose, needed to produce the observed signal, to the dose rate. Fine grains are more completely reset during faulting, and a plot of age vs. grain size shows a plateau for grains below critical size; these grains are presumed to have been completely zeroed by the last fault activity. We carried out ESR dating of fault rocks collected near the Gori nuclear reactor. Most of the ESR signals of fault rocks collected from the basement are saturated. This indicates that the last movement of the faults had occurred before the Quaternary period. However, ESR dates from the Oyong fault zone range from 370 to 310 ka. Results of this research suggest that long-term cyclic fault activity of the Oyong fault zone continued into the Pleistocene.

  13. Real-time fault diagnosis and fault-tolerant control


    Gao, Zhiwei; Ding, Steven X.; Cecati, Carlo


    This "Special Section on Real-Time Fault Diagnosis and Fault-Tolerant Control" of the IEEE Transactions on Industrial Electronics is motivated to provide a forum for academic and industrial communities to report recent theoretic/application results in real-time monitoring, diagnosis, and fault-tolerant design, and exchange the ideas about the emerging research direction in this field. Twenty-three papers were eventually selected through a strict peer-reviewed procedure, which represent the mo...

  14. Three-dimensional geologic framework modeling of faulted hydrostratigraphic units within the Edwards Aquifer, Northern Bexar County, Texas (United States)

    Pantea, Michael P.; Cole, James C.


    This report describes a digital, three-dimensional faulted hydrostratigraphic model constructed to represent the geologic framework of the Edwards aquifer system in the area of San Antonio, northern Bexar County, Texas. The model is based on mapped geologic relationships that reflect the complex structures of the Balcones fault zone, detailed lithologic descriptions and interpretations of about 40 principal wells (and qualified data from numerous other wells), and a conceptual model of the gross geometry of the Edwards Group units derived from prior interpretations of depositional environments and paleogeography. The digital model depicts the complicated intersections of numerous major and minor faults in the subsurface, as well as their individual and collective impacts on the continuity of the aquifer-forming units of the Edwards Group and the Georgetown Formation. The model allows for detailed examination of the extent of fault dislocation from place to place, and thus the extent to which the effective cross-sectional area of the aquifer is reduced by faulting. The model also depicts the internal hydrostratigraphic subdivisions of the Edwards aquifer, consisting of three major and eight subsidiary hydrogeologic units. This geologic framework model is useful for visualizing the geologic structures within the Balcones fault zone and the interactions of en-echelon fault strands and flexed connecting fault-relay ramps. The model also aids in visualizing the lateral connections between hydrostratigraphic units of relatively high and low permeability across the fault strands. Introduction The Edwards aquifer is the principal source of water for municipal, agricultural, industrial, and military uses by nearly 1.5 million inhabitants of the greater San Antonio, Texas, region (Hovorka and others, 1996; Sharp and Banner, 1997). Discharges from the Edwards aquifer also support local recreation and tourism industries at Barton, Comal, and San Marcos Springs located

  15. Segmentation and step-overs along strike-slip fault systems in the inner California borderlands: Implications for fault architecture and basin formation (United States)

    Maloney, J. M.; Driscoll, N. W.; Kent, G.; Brothers, D. S.


    Reprocessed, industry multichannel seismic reflection data and high resolution Chirp data were examined to characterize the geometry and recency of faulting in the inner California borderlands (ICB). Two end-member models have been proposed to explain the deformation observed in the ICB. One model invokes reactivation of detachment faults by the Oceanside Blind Thrust (OBT) to explain the deformation and margin architecture (e.g., San Mateo/Carlsbad Trend). In contrast, the other model explains the deformation by step-overs along the strike-slip fault systems. Several observations in both the southern and central portions of the ICB are more consistent with the step-over model than the regional blind thrust model. For example, regions in the ICB exhibit both tensional and compressional structures across the margin, which are more readily explained by the strike-slip model. Localized compression and extension occurs as predicted at fault bends and step-overs. Furthermore, strike slip fault systems that bound extensional regions (i.e., San Diego Bay) exhibit localized normal deformation as they approach the releasing step-overs. In addition, onlapping turbidites reveal that the deformation becomes younger toward the east, an observation not consistent with a westward verging blind thrust fault system. Finally, rotational deformation previously attributed to a splay off the OBT instead appears to be a southward transported gravitational slide deposit. In summary, the nested high-resolution Chirp and MCS data have provided new constraints on ICB tectonic deformation and margin architecture, which are best explained by step-overs on strike slip fault systems.

  16. Imaging of Subsurface Faults using Refraction Migration with Fault Flooding

    KAUST Repository

    Metwally, Ahmed Mohsen Hassan


    We propose a novel method for imaging shallow faults by migration of transmitted refraction arrivals. The assumption is that there is a significant velocity contrast across the fault boundary that is underlain by a refracting interface. This procedure, denoted as refraction migration with fault flooding, largely overcomes the difficulty in imaging shallow faults with seismic surveys. Numerical results successfully validate this method on three synthetic examples and two field-data sets. The first field-data set is next to the Gulf of Aqaba and the second example is from a seismic profile recorded in Arizona. The faults detected by refraction migration in the Gulf of Aqaba data were in agreement with those indicated in a P-velocity tomogram. However, a new fault is detected at the end of the migration image that is not clearly seen in the traveltime tomogram. This result is similar to that for the Arizona data where the refraction image showed faults consistent with those seen in the P-velocity tomogram, except it also detected an antithetic fault at the end of the line. This fault cannot be clearly seen in the traveltime tomogram due to the limited ray coverage.

  17. 75 FR 38412 - Safety Zone; San Diego POPS Fireworks, San Diego, CA (United States)


    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; San Diego POPS Fireworks, San Diego, CA... zone on the ] navigable waters of San Diego Bay in support of the San Diego POPS Fireworks. This safety... San Diego POPS Fireworks, which will include fireworks presentations conducted from a barge in San...

  18. Detecting Hidden Faults and Other Lineations with UAVSAR (United States)

    Parker, J. W.; Glasscoe, M. T.; Donnellan, A.


    Jay Parker, Margaret Glasscoe, Andrea Donnellan Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA The M7.2 El Mayor Cucapah Earthquake of April 4, 2010 is the main earthquake to date observed by the NASA UAVSAR. By observing with repeat passes (October 2009, April 2010 captures the coseismic strain pattern, and subsequent flights capture the postseismic process) over the adjoining portion of California, the interferometric phase maps of geodetic displacements are exceptionally high definition (pixel size is roughly 7 m) records of the extended deformation field from the earthquake process, including revelation of a rich network of plate parallel and conjugate faulting, apparently slipping sympathetically to the earthquake-induced quasistatic changes in stress. While the most significant of these faults have been documented by cooperative use of UAVSAR maps and field research, a subsequent opportunity arises: to use this data to develop and validate an automated approach to detecting faults and other lineations directly from the UAVSAR unwrapped phase product that corresponds to a single-component deformation map. The Canny edge detection algorithm is employed, after a preparation stage to clean the data. This preprocessing step is tailored to the nature of the radar phase data: data dropouts in single pixels and extended areas (blown sand dunes, farms) are a much larger problem than background white noise. Blocks of typically 3x3 pixels are currently reduced to a single value, the average after bad pixels are discarded. The smoothing methods typically used with the Canny method are minimized (smoothing makes data drop-out problems worse). The aperture size that determines a gradient estimation is chosen large (7 vs. the typical 3), as this is found to produce continuous (rather than dashed) lineations. The main Canny threshold is chosen to correspond to a user selected slip threshold in mm. Reasonable maps of lineations in the Salton

  19. Final Technical Report: PV Fault Detection Tool.

    Energy Technology Data Exchange (ETDEWEB)

    King, Bruce Hardison [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jones, Christian Birk [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)


    The PV Fault Detection Tool project plans to demonstrate that the FDT can (a) detect catastrophic and degradation faults and (b) identify the type of fault. This will be accomplished by collecting fault signatures using different instruments and integrating this information to establish a logical controller for detecting, diagnosing and classifying each fault.

  20. Seismological Studies for Tensile Faults

    Directory of Open Access Journals (Sweden)

    Gwo-Bin Ou


    Full Text Available A shear slip fault, an equivalence of a double couple source, has often been assumed to be a kinematic source model in ground motion simulation. Estimation of seismic moment based on the shear slip model indicates the size of an earthquake. However, if the dislocation of the hanging wall relative to the footwall includes not only a shear slip tangent to the fault plane but also expansion and compression normal to the fault plane, the radiating seismic waves will feature differences from those out of the shear slip fault. Taking account of the effects resulting from expansion and compression to a fault plane, we can resolve the tension and pressure axes as well as the fault plane solution more exactly from ground motions than previously, and can evaluate how far a fault zone opens or contracts during a developing rupture. In addition to a tensile angle and Poisson¡¦s ratio for the medium, a tensile fault with five degrees of freedom has been extended from the shear slip fault with only three degrees of freedom, strike, dip, and slip.

  1. Advanced cloud fault tolerance system (United States)

    Sumangali, K.; Benny, Niketa


    Cloud computing has become a prevalent on-demand service on the internet to store, manage and process data. A pitfall that accompanies cloud computing is the failures that can be encountered in the cloud. To overcome these failures, we require a fault tolerance mechanism to abstract faults from users. We have proposed a fault tolerant architecture, which is a combination of proactive and reactive fault tolerance. This architecture essentially increases the reliability and the availability of the cloud. In the future, we would like to compare evaluations of our proposed architecture with existing architectures and further improve it.

  2. Physical fault tolerance of nanoelectronics. (United States)

    Szkopek, Thomas; Roychowdhury, Vwani P; Antoniadis, Dimitri A; Damoulakis, John N


    The error rate in complementary transistor circuits is suppressed exponentially in electron number, arising from an intrinsic physical implementation of fault-tolerant error correction. Contrariwise, explicit assembly of gates into the most efficient known fault-tolerant architecture is characterized by a subexponential suppression of error rate with electron number, and incurs significant overhead in wiring and complexity. We conclude that it is more efficient to prevent logical errors with physical fault tolerance than to correct logical errors with fault-tolerant architecture.

  3. An Overview of Transmission Line Protection by Artificial Neural Network: Fault Detection, Fault Classification, Fault Location, and Fault Direction Discrimination

    Directory of Open Access Journals (Sweden)

    Anamika Yadav


    Full Text Available Contemporary power systems are associated with serious issues of faults on high voltage transmission lines. Instant isolation of fault is necessary to maintain the system stability. Protective relay utilizes current and voltage signals to detect, classify, and locate the fault in transmission line. A trip signal will be sent by the relay to a circuit breaker with the purpose of disconnecting the faulted line from the rest of the system in case of a disturbance for maintaining the stability of the remaining healthy system. This paper focuses on the studies of fault detection, fault classification, fault location, fault phase selection, and fault direction discrimination by using artificial neural networks approach. Artificial neural networks are valuable for power system applications as they can be trained with offline data. Efforts have been made in this study to incorporate and review approximately all important techniques and philosophies of transmission line protection reported in the literature till June 2014. This comprehensive and exhaustive survey will reduce the difficulty of new researchers to evaluate different ANN based techniques with a set of references of all concerned contributions.

  4. Presa de San Esteban

    Directory of Open Access Journals (Sweden)

    Equipo Editorial


    Full Text Available En el número 73 de esta revista se publicó un artículo, que trataba sobre los aprovechamientos hidroeléctricos de la cuenca del río Sil. En este trabajo se hace referencia, únicamente, a la importante presa de San Esteban, obra que, por so altura de salto, caudales disponibles y embalse, es la de mayor producción de las de la referida cuenca. Su proyección en planta e« circular, tipo gravedad, de 115 m de altura, y su embalse, de 213 millones de metros cúbicos.

  5. Fault Tolerant Distributive Processing (United States)

    Quesnell, Harris


    A fault tolerant design used to enhanced the survivability of a distributive processing system is described. Based on physical limitations, mission duration and maintenance support, the approach has emphasized functional redundancy in place of the traditional hardware or software level redundancy. A top down architecture within the system's hierarchy allows sharing of common resources. Various techniques used to enhance the survivability of the hardware at the equipment, module and component level were analyzed. The intent of the on going work is to demonstrate the ability of a distributive processing system to maintain itself for a long period of time.

  6. The Parkfield prediction experiment (United States)

    Lindh, A.; Evans, P.; Harsh, P.; Buhr, G.


    The San Andreas fault is part of the boundary between the Pacific and North American crustal plates. In California, movements of about 3 centimeters per year are currently taking place along the fault, although plat tectonic models suggest a faster rate of 5 cm/yr may be the average over a longer period of time and a broader area.

  7. Refining interseismic fault slip and shallow creep on the Hayward and Calaveras Faults, California, using UAVSAR, satellite InSAR and GPS data (United States)

    Farge, G.; Delbridge, B. G.; Materna, K.; Johnson, C. W.; Chaussard, E.; Jones, C. E.; Burgmann, R.


    Understanding the role of the Hayward/Calaveras fault junction in major earthquake ruptures in the East San Francisco Bay Area is a major challenge in trying to assess the regional seismic hazard. We use updated GPS velocities, and surface geodetic measurements from both traditional space-based InSAR and the NASA JPL's Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) system to quantify the deep long-term interseismic deformation and shallow temporally variable fault creep. Here, we present a large data set of interseismic deformation over the Hayward/Calaveras fault system, combining far-field deformation from 1992-2011 ERS and Envisat InSAR data, near-field deformation from 2009-2016 UAVSAR data and 1997-2016 regional GPS measurements from the Bay Area Velocity Unification model (BAVU4) in both near-field and far field. We perform a joint inversion of the data to obtain the long-term slip on deep through-going dislocations and the distribution of shallow creep on a 3D model of the Hayward and Calaveras faults. Spatially adaptative weights are given to each data set in order to account for its importance in constraining slip at different depths. The coherence and resolution of the UAVSAR data allow us to accurately resolve the near-field fault deformation, thus providing stronger constraints on the location of active strands of the southern Hayward and Calaveras faults and their shallow interseismic creep distribution.

  8. Central Asia Active Fault Database (United States)

    Mohadjer, Solmaz; Ehlers, Todd A.; Kakar, Najibullah


    The ongoing collision of the Indian subcontinent with Asia controls active tectonics and seismicity in Central Asia. This motion is accommodated by faults that have historically caused devastating earthquakes and continue to pose serious threats to the population at risk. Despite international and regional efforts to assess seismic hazards in Central Asia, little attention has been given to development of a comprehensive database for active faults in the region. To address this issue and to better understand the distribution and level of seismic hazard in Central Asia, we are developing a publically available database for active faults of Central Asia (including but not limited to Afghanistan, Tajikistan, Kyrgyzstan, northern Pakistan and western China) using ArcGIS. The database is designed to allow users to store, map and query important fault parameters such as fault location, displacement history, rate of movement, and other data relevant to seismic hazard studies including fault trench locations, geochronology constraints, and seismic studies. Data sources integrated into the database include previously published maps and scientific investigations as well as strain rate measurements and historic and recent seismicity. In addition, high resolution Quickbird, Spot, and Aster imagery are used for selected features to locate and measure offset of landforms associated with Quaternary faulting. These features are individually digitized and linked to attribute tables that provide a description for each feature. Preliminary observations include inconsistent and sometimes inaccurate information for faults documented in different studies. For example, the Darvaz-Karakul fault which roughly defines the western margin of the Pamir, has been mapped with differences in location of up to 12 kilometers. The sense of motion for this fault ranges from unknown to thrust and strike-slip in three different studies despite documented left-lateral displacements of Holocene and late

  9. Fault Monitooring and Fault Recovery Control for Position Moored Tanker

    DEFF Research Database (Denmark)

    Fang, Shaoji; Blanke, Mogens


    This paper addresses fault tolerant control for position mooring of a shuttle tanker operating in the North Sea. A complete framework for fault diagnosis is presented but the loss of a sub-sea mooring line buoyancy element is given particular attention, since this fault could lead to line breakage...... and risky abortion of an oil-loading operation. With signicant drift forces from waves, non-Gaussian elements dominate in residuals and fault diagnosis need be designed using dedicated change detection for the type of distribution encountered. In addition to dedicated diagnosis, an optimal position...... algorithm is proposed to accommodate buoyancy element failure and keep the mooring system in a safe state. Detection properties and fault-tolerant control are demonstrated by high delity simulations...

  10. Structure and flow properties of syn-rift border faults: The interplay between fault damage and fault-related chemical alteration (Dombjerg Fault, Wollaston Forland, NE Greenland) (United States)

    Kristensen, Thomas B.; Rotevatn, Atle; Peacock, David C. P.; Henstra, Gijs A.; Midtkandal, Ivar; Grundvåg, Sten-Andreas


    Structurally controlled, syn-rift, clastic depocentres are of economic interest as hydrocarbon reservoirs; understanding the structure of their bounding faults is of great relevance, e.g. in the assessment of fault-controlled hydrocarbon retention potential. Here we investigate the structure of the Dombjerg Fault Zone (Wollaston Forland, NE Greenland), a syn-rift border fault that juxtaposes syn-rift deep-water hanging-wall clastics against a footwall of crystalline basement. A series of discrete fault strands characterize the central fault zone, where discrete slip surfaces, fault rock assemblages and extreme fracturing are common. A chemical alteration zone (CAZ) of fault-related calcite cementation envelops the fault and places strong controls on the style of deformation, particularly in the hanging-wall. The hanging-wall damage zone includes faults, joints, veins and, outside the CAZ, disaggregation deformation bands. Footwall deformation includes faults, joints and veins. Our observations suggest that the CAZ formed during early-stage fault slip and imparted a mechanical control on later fault-related deformation. This study thus gives new insights to the structure of an exposed basin-bounding fault and highlights a spatiotemporal interplay between fault damage and chemical alteration, the latter of which is often underreported in fault studies. To better elucidate the structure, evolution and flow properties of faults (outcrop or subsurface), both fault damage and fault-related chemical alteration must be considered.

  11. Fault Management Design Strategies (United States)

    Day, John C.; Johnson, Stephen B.


    Development of dependable systems relies on the ability of the system to determine and respond to off-nominal system behavior. Specification and development of these fault management capabilities must be done in a structured and principled manner to improve our understanding of these systems, and to make significant gains in dependability (safety, reliability and availability). Prior work has described a fundamental taxonomy and theory of System Health Management (SHM), and of its operational subset, Fault Management (FM). This conceptual foundation provides a basis to develop framework to design and implement FM design strategies that protect mission objectives and account for system design limitations. Selection of an SHM strategy has implications for the functions required to perform the strategy, and it places constraints on the set of possible design solutions. The framework developed in this paper provides a rigorous and principled approach to classifying SHM strategies, as well as methods for determination and implementation of SHM strategies. An illustrative example is used to describe the application of the framework and the resulting benefits to system and FM design and dependability.

  12. Andreas Papandreou’s Exile Politics: The First Phase (1968-1970

    Directory of Open Access Journals (Sweden)

    Stan Draenos


    Full Text Available Andreas Papandreou’s exile politics, following his December 1967 release from Averoff Prison, have stereotypically been seen as simply adopting the neo-Marxist ideologies associated with the Third World national liberation movements of the era. In narrating the initial evolution of his views on the “Greek Question” in exile, this study attempts to surface the underlying dynamics responsible for radicalizing his politics in that direction. Those dynamics reflect, on the one hand, the relentless will-to-action informing Papandreou’s political persona and, on the other, the political upheavals, headlined by the protest movement against the US war in Vietnam, in which his politics were enmeshed.

  13. Andreas Vesalius as a renaissance innovative neuroanatomist: his 5th centenary of birth. (United States)

    Gomes, Marleide da Mota; Moscovici, Mauricio; Engelhardt, Eliasz


    Andreas Vesalius (1514-1564) is considered the Father of Modern Anatomy, and an authentic representative of the Renaissance. His studies, founded on dissection of human bodies, differed from Galeno, who based his work on dissection of animals, constituted a notable scientific advance. Putting together science and art, Vesalius associated himself to artists of the Renaissance, and valued the images of the human body in his superb work De Humani Corporis Fabrica.This paper aims to honor this extraordinary European Renaissance physician and anatomist, who used aesthetic appeal to bind text and illustration, science and art. His achievements are highlighted, with an especial attention on neuroanatomy. Aspects about his personal life and career are also focused.

  14. Animals, Pictures, and Skeletons: Andreas Vesalius's Reinvention of the Public Anatomy Lesson. (United States)

    Shotwell, R Allen


    In this paper, I examine the procedures used by Andreas Vesalius for conducting public dissections in the early sixteenth century. I point out that in order to overcome the limitations of public anatomical demonstration noted by his predecessors, Vesalius employed several innovative strategies, including the use of animals as dissection subjects, the preparation and display of articulated skeletons, and the use of printed and hand-drawn illustrations. I suggest that the examination of these three strategies for resolving the challenges of public anatomical demonstration helps us to reinterpret Vesalius's contributions to sixteenth-century anatomy. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail:

  15. Andreas Vesalius' five hundreth anniversary: initiation of the rotator cuff concept. (United States)

    Brinkman, Romy J; Hage, J Joris


    The rotator cuff concept refers to the four scapulohumeral muscles that stabilize and rotate the humerus relative to the scapula. To date, the first description of the rotator cuff remained unidentified. In light of the 500th birthday of Andreas Vesalius (1515-1564) we searched his 1543 masterwork "Fabrica Corporis Humani Libri Septem" for references to the morphology and function of the rotator cuff muscles. Even though he distinguished three rather than four scapulohumeral muscles, Vesalius recognized the need for structures that prevent dislocation of the shoulder inherent to the morphology of the humeral caput and scapular socket. He recorded "three strong ligaments" and the "three muscles that rotate the arm" of which the tendons completely "embrace the ligaments of the joint" as such structures. Vesalius defined the rotator cuff concept avant la lettre.

  16. Andreas Vesalius' 500th Anniversary: Initiation of the Superficial Facial System and Superficial Musculoaponeurotic System Concepts. (United States)

    Brinkman, Romy J; Hage, J Joris


    Because of their relevance for liposuction and rhytidectomies, respectively, the superficial fascial system (SFS) and superficial musculoaponeurotic system (SMAS) have been thoroughly studied over the past decennia. Although it is well known that the SMAS concept was introduced by Tessier in 1974, it remains unknown who first properly described the stratum membranosum of the SFS. In light of the 500th birthday of Andreas Vesalius (1515-1564), we searched his 1543 masterwork De Humani Corporis Fabrica Libri Septem and related work for references to these structures. We found ample reference to both structures as the membrana carnosa (or fleshy membrane) in his works and concluded that Vesalius recognized the extension, nature, and functions of the stratum membranosum of the SFS, as well as its more musculous differentiation as the SMAS in the head and neck area, and the dartos in the perineogenital area. In doing so, Vesalius recorded most details of the SFS and SMAS concepts avant la lettre.

  17. Andreas Vesalius' 500th Anniversary: First Description of the Mammary Suspensory Ligaments. (United States)

    Brinkman, Romy J; Hage, J Joris


    Sir Astley Paston Cooper has, to date, been acknowledged to be the first to describe the suspensory ligaments of the breast, or Cooper's ligaments, in 1840. We found these ligaments to be recorded in the first edition of 'De Humani Corporis Fabrica Libri Septem' by Andreas Vesalius, published in 1543. To commemorate Vesalius' 500th birthday, we quote and discuss this earlier record. Vesalius' record of the nature and function of the fleshy membrane between mammary gland and pectoral muscle, the hard fat intervening the mammary glands, and the fibers running from the fleshy membrane to the skin are a clear representation of posterior layer of the superficial fascial system, the fibro-adipose stroma surrounding and linking the mammary glandular elements, and the suspensory ligaments as we know them. Vesalius recorded the anatomy and function of the latter structures nearly 300 years before Sir Astley Paston Cooper did.

  18. ANDREA 2.2 and 2.3. Advances in modelling of VVER cores

    Energy Technology Data Exchange (ETDEWEB)

    Havluj, Frantisek; Hejzlar, Jonatan; Vocka, Radim; Vysoudil, Jiri [UJV Rez, Husinec-Rez (Czech Republic)


    In 2016 a new version of code ANDREA for core design and reload safety analysis of VVER reactors has been released. The new code version includes several major improvements. The first of them is a seamless incorporation of short time kinetics calculations (without temperature feedback) into the code. This new feature accompanied by the possibility of excore detector signal predictions enables precise interpretation of dynamic measurements of control assembly weight during the reactor startup. Second important enhancement resides in new flexible format of cross section libraries and in new fuel temperature model based on results of TRANSURANUS fuel performance code. The new code version has been thoroughly tested and validated for both VVER440 and VVER-1000 reactors. Furthermore for the new version 2.3 which is to be released shortly we have implemented the possibility of fluent control assemblies' motion and of non-equidistant axial nodalization schemes in VVER-440 calculations.

  19. Reviews by Barbara Santini, Andrea Mecacci, Mariagrazia Portera, Francesca Zugno, and Alberto Ricci

    Directory of Open Access Journals (Sweden)

    Fausto Cercignani


    Full Text Available Review of Daniele Goldoni’s book Gratitudine. Voci di Hölderlin (2013, by Barbara Santini.Review of Laura Anna Macor’s book La fragilità delle virtù. Dall’antropologia alla morale e ritorno nell’epoca di Kant (2011, by Andrea Mecacci.Review of the collection of essays Friedrich Hölderlin. Pensiero e poesia, ed. by Elena Polledri (special volume of the journal «Humanitas», 2012, by Mariagrazia Portera.Review of Barbara Santini’s book Soggetto e fondamento in Hölderlin tra filosofia trascendentale e pensiero speculativo (2013, by Francesca Zugno.Review of Francesca Zugno’s book Hölderlin oltre Kant. Verso Hyperion. 1794-1797 (2011, by Alberto Ricci.

  20. Andreas Vesalius as a renaissance innovative neuroanatomist: his 5th centenary of birth

    Directory of Open Access Journals (Sweden)

    Marleide da Mota Gomes


    Full Text Available Andreas Vesalius (1514-1564 is considered the Father of Modern Anatomy, and an authentic representative of the Renaissance. His studies, founded on dissection of human bodies, differed from Galeno, who based his work on dissection of animals, constituted a notable scientific advance. Putting together science and art, Vesalius associated himself to artists of the Renaissance, and valued the images of the human body in his superb work De Humani Corporis Fabrica.This paper aims to honor this extraordinary European Renaissance physician and anatomist, who used aesthetic appeal to bind text and illustration, science and art. His achievements are highlighted, with an especial attention on neuroanatomy. Aspects about his personal life and career are also focused.

  1. Review Essay: Faltering Forms Go to School. Analysis of the Subject in Connection With Andreas Reckwitz

    Directory of Open Access Journals (Sweden)

    Johannes Twardella


    Full Text Available In his book "Subjectivity," Andreas RECKWITZ interprets the work of a series of structuralist and poststructuralist authors in relation to the analysis of subjectivity. In the following article I reconstruct this interpretation and attempt to critically analyze the empirical explanatory power of these authors. An excerpt from the school routine of a German class is used to show how these various "subject-theoretical analysis strategies" may lead to different, interesting, and insightful interpretations. It also becomes clear that the idea of subjectivity, and therefore of education and maturity, cannot be abandoned. Without this idea, the application of pedagogy would be cynical, and the ability to understand it impossible. URN: urn:nbn:de:0114-fqs090222

  2. Los Angeles og San Francisco

    DEFF Research Database (Denmark)

    Ørstrup, Finn Rude


    Kompendium udarbejdet til en studierejse til Los Angeles og San Francisco april-maj 1998 Kunstakademiets Arkitektskole, Institut 3H......Kompendium udarbejdet til en studierejse til Los Angeles og San Francisco april-maj 1998 Kunstakademiets Arkitektskole, Institut 3H...

  3. A proposed test area for the spaceborne geodynamic ranging system (United States)

    Lowman, P. D., Jr.


    Precise geodetic measurements are proposed in which an orbiting laser obtains intersite distance between retroreflectors 25 to 100 km apart on the ground. The recommended area is a rectangle 200 by 400 km in southern California and adjacent Nevada, trending northeast. It includes the entire width of the San Andreas fault zone, the Garlock fault, the thrust faults of the Transverse Ranges, and the active strike-slip faults of the Mojave Desert.

  4. Fault tolerance in "multiprocessor systems

    Indian Academy of Sciences (India)

    puter architecture; [multiprocessor systems; reconfiguration; system- level diagnosis; VLSI processor arrays. 1. Introduction. Fault-tolerant computing can be defined as the ability to execute specified algorithms correctly inspite of the presence of faults. The complexity of supersystems and the increasing use of such computer ...

  5. Seismic constraints on the architecture of the Newport-Inglewood/Rose Canyon fault: Implications for the length and magnitude of future earthquake ruptures (United States)

    Sahakian, Valerie; Bormann, Jayne; Driscoll, Neal; Harding, Alistair; Kent, Graham; Wesnousky, Steve


    The Newport-Inglewood/Rose Canyon (NIRC) fault zone is an active strike-slip fault system within the Pacific-North American plate boundary in Southern California, located in close proximity to populated regions of San Diego, Orange, and Los Angeles counties. Prior to this study, the NIRC fault zone's continuity and geometry were not well constrained. Nested marine seismic reflection data with different vertical resolutions are employed to characterize the offshore fault architecture. Four main fault strands are identified offshore, separated by three main stepovers along strike, all of which are 2 km or less in width. Empirical studies of historical ruptures worldwide show that earthquakes have ruptured through stepovers with this offset. Models of Coulomb stress change along the fault zone are presented to examine the potential extent of future earthquake ruptures on the fault zone, which appear to be dependent on the location of rupture initiation and fault geometry at the stepovers. These modeling results show that the southernmost stepover between the La Jolla and Torrey Pines fault strands may act as an inhibitor to throughgoing rupture due to the stepover width and change in fault geometry across the stepover; however, these results still suggest that rupture along the entire fault zone is possible.

  6. Fault tolerant control for switched linear systems

    CERN Document Server

    Du, Dongsheng; Shi, Peng


    This book presents up-to-date research and novel methodologies on fault diagnosis and fault tolerant control for switched linear systems. It provides a unified yet neat framework of filtering, fault detection, fault diagnosis and fault tolerant control of switched systems. It can therefore serve as a useful textbook for senior and/or graduate students who are interested in knowing the state-of-the-art of filtering, fault detection, fault diagnosis and fault tolerant control areas, as well as recent advances in switched linear systems.  

  7. Using InSAR time series to identify geologic hazards associated with the Hayward and Calaveras faults along the South Bay Aqueduct (United States)

    Jones, C. E.; Burgmann, R.; Hoirup, D. F., Jr.; Hawkins, B.


    We evaluated Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) data using InSAR time series analysis and documented ground movement along the Calaveras and Hayward faults near the South Bay Aqueduct (SBA). Images from seven different UAVSAR flight lines at 7m x 7m resolution were used for the study. A total of 132 acquisitions (between 12 and 51 per line) were acquired between 2009 and 2015. Each of the seven lines observed only part of the aqueduct, but all segments of the aqueduct were imaged in more than one line with some segments in up to four lines. This provided between one and three imaging geometries for every fault location along the aqueduct. The SBA transports water from the Sacramento-San Joaquin Delta (Delta) to communities east and south of San Francisco Bay through a combination of open canals, tunnels, and pipelines. From its starting point immediately west of the Delta at Bethany Reservoir, the SBA extends westward, crossing multiple faults, including Calaveras and Hayward faults. The aqueduct continues south, largely following the Hayward fault to its terminus east of San Jose. The SBA and associated infrastructure are at risk from landslides and from movement along any of these faults, with the landslides often spatially associated with the faults. We report linear rates of surface movement averaged across the six-year time period, and identify locations experiencing significant movement along the Calaveras and Hayward faults. Aseismic displacement is quantified and mapped for the two faults, including multiple traces of the Calaveras fault extending north and south of where it crosses the SBA. This work was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under contracts with the California Dept. of Water Resources and with the National Aeronautics and Space Administration.

  8. Optimal Configuration of Fault-Tolerance Parameters for Distributed Server Access

    DEFF Research Database (Denmark)

    Daidone, Alessandro; Renier, Thibault; Bondavalli, Andrea


    Server replication is a common fault-tolerance strategy to improve transaction dependability for services in communications networks. In distributed architectures, fault-diagnosis and recovery are implemented via the interaction of the server replicas with the clients and other entities...... such as enhanced name servers. Such architectures provide an increased number of redundancy configuration choices. The influence of a (wide area) network connection can be quite significant and induce trade-offs between dependability and user-perceived performance. This paper develops a quantitative stochastic...... model using stochastic activity networks (SAN) for the evaluation of performance and dependability metrics of a generic transaction-based service implemented on a distributed replication architecture. The composite SAN model can be easily adapted to a wide range of client-server applications deployed...

  9. Fault Current Characteristics of the DFIG under Asymmetrical Fault Conditions

    Directory of Open Access Journals (Sweden)

    Fan Xiao


    Full Text Available During non-severe fault conditions, crowbar protection is not activated and the rotor windings of a doubly-fed induction generator (DFIG are excited by the AC/DC/AC converter. Meanwhile, under asymmetrical fault conditions, the electrical variables oscillate at twice the grid frequency in synchronous dq frame. In the engineering practice, notch filters are usually used to extract the positive and negative sequence components. In these cases, the dynamic response of a rotor-side converter (RSC and the notch filters have a large influence on the fault current characteristics of the DFIG. In this paper, the influence of the notch filters on the proportional integral (PI parameters is discussed and the simplified calculation models of the rotor current are established. Then, the dynamic performance of the stator flux linkage under asymmetrical fault conditions is also analyzed. Based on this, the fault characteristics of the stator current under asymmetrical fault conditions are studied and the corresponding analytical expressions of the stator fault current are obtained. Finally, digital simulation results validate the analytical results. The research results are helpful to meet the requirements of a practical short-circuit calculation and the construction of a relaying protection system for the power grid with penetration of DFIGs.

  10. Constraining fault growth rates and fault evolution in New Zealand (United States)

    Lamarche, Geoffroy; Bull, Jonathan M.; Barnes, Phil M.; Taylor, Susanna K.; Horgan, Huw


    Understanding how faults propagate, grow, and interact in fault systems is important because they are primarily responsible for distributing strain in the upper crust. They localize deformation and stress release, often producing surface displacements that control sedimentation and fluid flow, either by acting as conduits or barriers. Identifying fault spatial distribution, quantifying activity, evaluating linkage mechanisms, and estimating fault growth rates are key components in seismic risk evaluation. Scientists from the National Institute of Water and Atmospheric Research (NIWA), New Zealand, and the Southampton Oceanography Centre, United Kingdom, are working on a collaborative project that aims to improve understanding of faulting processes in the Earth's crust.The program comprises two research cruises to survey the Whakatane Graben, New Zealand, which is a zone of intense seismicity active extensional faulting, and rapid subsidence within the back-arc region of the Pacific-Australia plate boundary zone (Figure 1). Few places in the world offer the same opportunity to study the mechanisms by which major crustal faults have grown from small- to large-scale structures capable of generating moderate to large-magnitude earthquakes.

  11. Characterizing Slow Slip Events on the Hayward Fault from Two Decades of SBAS-InSAR Data (United States)

    Johanson, I. A.; Burgmann, R.


    In the San Francisco Bay Area (SFBA), two million people live in a geologically complex, tectonically active region that has experienced several historic earthquakes, including the 1868 Hayward, the 1906 San Francisco, and 1989 Loma Prieta earthquakes. The Uniform California Earthquake Rupture Forecast (2008) puts a 63% probability of a M6.7 or greater in the SFBA before 2038 and a 31% probability for the Hayward fault alone, the highest for any fault in the SFBA. The Hayward fault along the eastern side of San Francisco Bay is arguably one of the most hazardous faults in the world when one combines the probability of an earthquake with proximity to urban centers. Assessment of earthquake potential along Bay Area faults is complicated by the recognition that the system is not static and, in particular, that creep rates vary through time. Hayward fault monitoring by creepmeter, strainmeter and alinement array has detected a number of variations in creep rate on the Hayward fault. The largest in 1996, when an alinement array survey detected a SSE that produced 18 mm of fault creep within at most 63 days. The SSE also marked a change in longer-term creep rate, from nearly zero post-Loma Prieta to 3.9 mm/yr, still lower than the pre-Loma Prieta rate of ~9 mm/yr. More recent alinement array surveys (since 2006) show an increase in creep rates on the southern Hayward fault by ~2-5 mm/yr over the long-term average. The Small Baseline Subset (SBAS) approach is a method for extracting time series of range change at certain locations from a large set of InSAR data and is well suited to reveal time varying deformation without a known functional form. This project incorporates time series processing of InSAR data spanning 18 years and three satellites, together with 17 years of GPS acquisitions. In particular, we use these data to investigate slow slip events (SSEs) on the Hayward fault. The spatial density of SBAS-InSAR gives us more information on the spatial extent of the

  12. Active fault traces along Bhuj Fault and Katrol Hill Fault, and ...

    Indian Academy of Sciences (India)

    observed on the left bank of a stream cutting the terrace. Faulting is well revealed by 10–30 cm thick gouge. Lack of any corroborating evidence show- ing displacement of Quaternary deposits makes it difficult to decipher the active nature of the fault. However, the probability cannot be ruled- out. In the outlet of the small ...

  13. Dynamics of Earthquake Faults

    CERN Document Server

    Carlson, J M; Shaw, B E


    We present an overview of our ongoing studies of the rich dynamical behavior of the uniform, deterministic Burridge--Knopoff model of an earthquake fault. We discuss the behavior of the model in the context of current questions in seismology. Some of the topics considered include: (1) basic properties of the model, such as the magnitude vs. frequency distribution and the distinction between small and large events; (2) dynamics of individual events, including dynamical selection of rupture propagation speeds; (3) generalizations of the model to more realistic, higher dimensional models; (4) studies of predictability, in which artificial catalogs generated by the model are used to test and determine the limitations of pattern recognition algorithms used in seismology.

  14. Local versus regional active stress field in 5900m San Gregorio Magno 1 well (southern Apennines, Italy). (United States)

    Pierdominici, S.; Montone, P.; Mariucci, M. T.


    The aim of this work is to characterize the local stress field in a peculiar sector of the southern Apennines by analyzing borehole breakouts, fractures and logging data along the San Gregorio Magno 1 deep well, and to compare the achieved stress field with the regional one. The study area is characterized by diffuse low-Magnitude seismicity, although in historical times it has been repeatedly struck by moderate to large earthquakes. We have analyzed in detail the 5900m San Gregorio Magno 1 well drilled in 1996-97 by ENI S.p.A. and located very close (1.3 km away) to the Irpinia Fault. This fault was responsible of the strongest earthquake happened in this area, the 23rd November 1980 M6.9 earthquake that produced the first unequivocal historical surface faulting ever documented in Italy. The mainshock enucleated on a fault 38 km-long with a strike of 308° and 60-70° northeast-dipping, consistent with a NE-SW T-axis and a normal faulting tectonic regime. Borehole breakouts, active faults and focal mechanism solutions have allowed to define the present-day stress along and around the San Gregorio Magno 1 well and other analysis (logging data) to discriminate the presence of fracture zones and/or faults at depth. We have considered data from 1200m to the bottom of San Gregorio Magno 1 well. Our analysis of stress-induced wellbore breakouts shows an inhomogeneous direction of minimum horizontal stress (N359+-31°) orientation along the well. This direction is moderately consistent with the Shmin-trend determined from breakouts in other wells in this region and also with the regional active stress field inferred from active faults and earthquake focal plane solutions (N44 Shmin oriented). For this reason we have computed for each breakout zone the difference between the local trend and the regional one; comparing these breakout rotations with the spikes or changing trend of logs we have identified possible fractures or faults at different depths. We have correlated

  15. Mineralogy, mineral chemistry, and paragenesis of gold, silver, and base-metal ores of the North Amethyst vein system, San Juan Mountains, Mineral County, Colorado (United States)

    Foley, Nora K.; Caddey, Stanton W.; Byington, Craig B.; Vardiman, David M.


    Gold-rich adularia-sericite-type mineralization occurs near the southern margin of the San Luis caldera, at the intersection of the Equity fault and the northern extension of the Amethyst fault system. Mineralized rock is confined primarily to steeply dipping structures in silicified rhyolite and dacite. Intense sericitic alteration occurs at higher levels in the vein system, and wall rock adjacent to some veins is bleached. The ores are multiply brecciated, and vein filling locally shows sedimentary textures.

  16. Architecture of thrust faults with alongstrike variations in fault-plane dip: anatomy of the Lusatian Fault, Bohemian Massif

    Czech Academy of Sciences Publication Activity Database

    Coubal, Miroslav; Adamovič, Jiří; Málek, Jiří; Prouza, V.


    Roč. 59, č. 3 (2014), s. 183-208 ISSN 1802-6222 Institutional support: RVO:67985831 ; RVO:67985891 Keywords : fault architecture * fault plane geometry * drag structures * thrust fault * sandstone * Lusatian Fault Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.405, year: 2014

  17. Geomorphological mapping of the San Lorenzo area Sant'arcangelo region Southern Italy

    Directory of Open Access Journals (Sweden)

    Muh Aris Marfai


    The Sant'Arcangelo region is composed of 4 cycles both marine and continental in origin, all deposited on different environments: The Caliandro, Agri, San Lorenzo and Sauro cycles. The study area consists of Sauro and San Lorenzo Cycle. Sauro Cycle is Comprises of three heterotrophic units deposited in sintectonic discordance over the Agri cycle. San Lorenzo Cycle lying in unconformity over the precedent cycles is consisting of three units, namely conglomerates on the base part as well as on the top part of the sequence, and silty clays in the intermediate part. They form a syncline structure which ax has a NW-SE direction. The main structural features are represented by the San Lorenzo syncline and the Alianello fault. The San Lorenzo area has three principal origins: alluvial, denudation, and structural. Due to the geological-tectonic complexity, the structural landform is normally found as structural denudational landform. San Lorenzo area comprises of 41 landform units, namely 3 units of alluvial landforni, 26 units of denudational landform and 11 units of structural denudational landform.

  18. Deep Fault Drilling Project—Alpine Fault, New Zealand

    Directory of Open Access Journals (Sweden)

    Rupert Sutherland


    Full Text Available The Alpine Fault, South Island, New Zealand, constitutes a globally significant natural laboratory for research into how active plate-bounding continental faults work and, in particular, how rocks exposed at the surface today relate to deep-seated processes of tectonic deformation, seismogenesis, and mineralization. The along-strike homogeneity of the hanging wall, rapid rate of dextral-reverse slip on an inclined fault plane, and relatively shallow depths to mechanical and chemical transitions make the Alpine Fault and the broader South Island plate boundary an important international site for multi-disciplinary research and a realistic target for an ambitious long-term program of scientific drilling investigations.

  19. Fault Monitoring and Fault Recovery Control for Position Moored Tanker

    DEFF Research Database (Denmark)

    Fang, Shaoji; Blanke, Mogens


    This paper addresses fault tolerant control for position mooring of a shuttle tanker operating in the North Sea. A complete framework for fault diagnosis is presented but the loss of a sub-sea mooring line buoyancy element is given particular attention, since this fault could lead to mooring line...... breakage and a high-risk abortion of an oil-loading operation. With significant drift forces from waves, non-Gaussian elements dominate forces and the residuals designed for fault diagnosis. Hypothesis testing need be designed using dedicated change detection for the type of distribution encountered....... In addition to dedicated diagnosis, an optimal position algorithm is proposed to accommodate buoyancy element failure and keep the mooring system in a safe state. Furthermore, even in the case of line breakage, this optimal position strategy could be utilised to avoid breakage of a second mooring line...

  20. Method of locating ground faults (United States)

    Patterson, Richard L. (Inventor); Rose, Allen H. (Inventor); Cull, Ronald C. (Inventor)


    The present invention discloses a method of detecting and locating current imbalances such as ground faults in multiwire systems using the Faraday effect. As an example, for 2-wire or 3-wire (1 ground wire) electrical systems, light is transmitted along an optical path which is exposed to magnetic fields produced by currents flowing in the hot and neutral wires. The rotations produced by these two magnetic fields cancel each other, therefore light on the optical path does not read the effect of either. However, when a ground fault occurs, the optical path is exposed to a net Faraday effect rotation due to the current imbalance thereby exposing the ground fault.

  1. Geothermal resource assessment of western San Luis Valley, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Zacharakis, Ted G.; Pearl, Richard Howard; Ringrose, Charles D.


    The Colorado Geological Survey initiated and carried out a fully integrated assessment program of the geothermal resource potential of the western San Luis Valley during 1979 and 1980. The San Luis Valley is a large intermontane basin located in southcentral Colorado. While thermal springs and wells are found throughout the Valley, the only thermal waters found along the western part of the Valley are found at Shaw Warm Springs which is a relatively unused spring located approximately 6 miles (9.66 km) north of Del Norte, Colorado. The waters at Shaws Warm Spring have a temperature of 86 F (30 C), a discharge of 40 gallons per minute and contain approximately 408 mg/l of total dissolved solids. The assessment program carried out din the western San Luis Valley consisted of: soil mercury geochemical surveys; geothermal gradient drilling; and dipole-dipole electrical resistivity traverses, Schlumberger soundings, Audio-magnetotelluric surveys, telluric surveys, and time-domain electro-magnetic soundings and seismic surveys. Shaw Warm Springs appears to be the only source of thermal waters along the western side of the Valley. From the various investigations conducted the springs appear to be fault controlled and is very limited in extent. Based on best evidence presently available estimates are presented on the size and extent of Shaw Warm Springs thermal system. It is estimated that this could have an areal extent of 0.63 sq. miles (1.62 sq. km) and contain 0.0148 Q's of heat energy.

  2. Subsurface fault geometries in Southern California illuminated through Full-3D Seismic Waveform Tomography (F3DT) (United States)

    Lee, En-Jui; Chen, Po


    More precise spatial descriptions of fault systems play an essential role in tectonic interpretations, deformation modeling, and seismic hazard assessments. The recent developed full-3D waveform tomography techniques provide high-resolution images and are able to image the material property differences across faults to assist the understanding of fault systems. In the updated seismic velocity model for Southern California, CVM-S4.26, many velocity gradients show consistency with surface geology and major faults defined in the Community Fault Model (CFM) (Plesch et al. 2007), which was constructed by using various geological and geophysical observations. In addition to faults in CFM, CVM-S4.26 reveals a velocity reversal mainly beneath the San Gabriel Mountain and Western Mojave Desert regions, which is correlated with the detachment structure that has also been found in other independent studies. The high-resolution tomographic images of CVM-S4.26 could assist the understanding of fault systems in Southern California and therefore benefit the development of fault models as well as other applications, such as seismic hazard analysis, tectonic reconstructions, and crustal deformation modeling.

  3. Orientations of faults determined by premonitory shear zones (United States)

    Johnson, Arvid M.


    to fault is known to be positive. According to the postulate, the shear zones should be oriented at angles less than 45° to the compression direction, and it is well known that faults in rock specimens have such orientations. The postulate also predicts the strikingly different orientations of kink bands in foliated materials. Unlike faults in granite specimens, kink bands and the faults that form along them are commonly oriented at angles greater than 45° to the maximum compression. Analysis of kink-band formation indicates that the coefficient of dilatancy is typically negative if the contact strength between layers is frictional, and the postulate affirms that the negative dilatancy will result in the observed orientations. Associations of faults with well-defined shear zones consisting of numerous deformation bands in the Entrada Sandstone in Utah's San Rafael Desert illustrate clearly the control that premonitory shear zones have over the orientations of faults in these rocks. The orientations of conjugate shear zones, both in normal and strike-slip systems, indicate that the angle of dilatancy of the sandstone was about 60°, indicating that the dilatancy was positive at the time the orientations of the shear zones were determined, in spite of microscopic evidence that the volume decreased at some time during the formation of the shear zones. The faults that Gerhard Oertel produced in claycake experiments are amazing, but their orientations can be understood in terms of the postulate of premonitory shear zones: These experiments emphasize, perhaps more strongly than any of the other examples we have considered, the importance of understanding the mechanisms of deformation in the material under study. In compression experiments, the angle between the maximum compression and the faults is a highly obtuse angle of 83° whereas, in extension experiments, the angle is a highly acute angle of 7°! The postulate indicates that, in compression experiments, the clay

  4. Fault Features Extraction and Identification based Rolling Bearing Fault Diagnosis (United States)

    Qin, B.; SUN, G. D.; ZHANG, L. Y.; WANG, J. G.; HU, J.


    For the fault classification model based on extreme learning machine (ELM), the diagnosis accuracy and stability of rolling bearing is greatly influenced by a critical parameter, which is the number of nodes in hidden layer of ELM. An adaptive adjustment strategy is proposed based on vibrational mode decomposition, permutation entropy, and nuclear kernel extreme learning machine to determine the tunable parameter. First, the vibration signals are measured and then decomposed into different fault feature models based on variation mode decomposition. Then, fault feature of each model is formed to a high dimensional feature vector set based on permutation entropy. Second, the ELM output function is expressed by the inner product of Gauss kernel function to adaptively determine the number of hidden layer nodes. Finally, the high dimension feature vector set is used as the input to establish the kernel ELM rolling bearing fault classification model, and the classification and identification of different fault states of rolling bearings are carried out. In comparison with the fault classification methods based on support vector machine and ELM, the experimental results show that the proposed method has higher classification accuracy and better generalization ability.

  5. Riparian Habitat - San Joaquin River (United States)

    California Department of Resources — The immediate focus of this study is to identify, describe and map the extent and diversity of riparian habitats found along the main stem of the San Joaquin River,...

  6. Active fault diagnosis by temporary destabilization

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob


    An active fault diagnosis method for parametric or multiplicative faults is proposed. The method periodically adds a term to the controller that for a short period of time renders the system unstable if a fault has occurred, which facilitates rapid fault detection. An illustrative example is given....

  7. Fault isolatability conditions for linear systems

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, Henrik


    In this paper, we shall show that an unlimited number of additive single faults can be isolated under mild conditions if a general isolation scheme is applied. Multiple faults are also covered. The approach is algebraic and is based on a set representation of faults, where all faults within a set...

  8. Active Fault Diagnosis by Temporary Destabilization

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, Henrik


    An active fault diagnosis method for parametric or multiplicative faults is proposed. The method periodically adds a term to the controller that for a short period of time renders the system unstable if a fault has occurred, which facilitates rapid fault detection. An illustrative example is given....

  9. Fault Detection for Diesel Engine Actuator

    DEFF Research Database (Denmark)

    Blanke, M.; Bøgh, S.A.; Jørgensen, R.B.


    Feedback control systems are vulnerable to faults in control loop sensors and actuators, because feedback actions may cause abrupt responses and process damage when faults occur.......Feedback control systems are vulnerable to faults in control loop sensors and actuators, because feedback actions may cause abrupt responses and process damage when faults occur....

  10. An unknown treasure in Brugge (Bruges): the oldest portrait of Andreas Vesallius on a stained glass window. (United States)

    Steeno, Omer P; Deruyttere, Michel


    Four iconographic pictures of Andreas Vesalius on glass painted windows, in Rochester, Minnesota, USA; Leuven (Louvain, Belgium); Saint Paul, Minnesota, USA; and Innsbruck (Austria), were made in the period between 1943 and 1956. Recently, we have found in Brugge (Bruges) a much older portrait of Vesalius, in the form of a medallion on glass. It was painted between 1860 and 1870 by Samuel Coucke who had been commissioned by Dr. François Vanden Abeele for the decoration of his medical office.

  11. Fault Tolerant External Memory Algorithms

    DEFF Research Database (Denmark)

    Jørgensen, Allan Grønlund; Brodal, Gerth Stølting; Mølhave, Thomas


    bound on the number of I/Os required for any deterministic dictionary that is resilient to memory faults. We design a static and a dynamic deterministic dictionary with optimal query performance as well as an optimal sorting algorithm and an optimal priority queue. Finally, we consider scenarios where......Algorithms dealing with massive data sets are usually designed for I/O-efficiency, often captured by the I/O model by Aggarwal and Vitter. Another aspect of dealing with massive data is how to deal with memory faults, e.g. captured by the adversary based faulty memory RAM by Finocchi and Italiano....... However, current fault tolerant algorithms do not scale beyond the internal memory. In this paper we investigate for the first time the connection between I/O-efficiency in the I/O model and fault tolerance in the faulty memory RAM, and we assume that both memory and disk are unreliable. We show a lower...

  12. Static Decoupling in fault detection

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik


    An algebraic approach is given for a design of a static residual weighting factor in connection with fault detection. A complete parameterization is given of the weighting factor which will minimize a given performance index...

  13. Diagnosis and fault-tolerant control

    CERN Document Server

    Blanke, Mogens; Lunze, Jan; Staroswiecki, Marcel


    Fault-tolerant control aims at a gradual shutdown response in automated systems when faults occur. It satisfies the industrial demand for enhanced availability and safety, in contrast to traditional reactions to faults, which bring about sudden shutdowns and loss of availability. The book presents effective model-based analysis and design methods for fault diagnosis and fault-tolerant control. Architectural and structural models are used to analyse the propagation of the fault through the process, to test the fault detectability and to find the redundancies in the process that can be used to ensure fault tolerance. It also introduces design methods suitable for diagnostic systems and fault-tolerant controllers for continuous processes that are described by analytical models of discrete-event systems represented by automata. The book is suitable for engineering students, engineers in industry and researchers who wish to get an overview of the variety of approaches to process diagnosis and fault-tolerant contro...

  14. Environmental assessment : Rodent control program : San Joaquin river levee : San Luis National Wildlife Refuge (United States)

    US Fish and Wildlife Service, Department of the Interior — The Lower San Joaquin Levee District (LSJLD) requires that six miles of levee situated along the San Joaquin River on San Luis National Wildlife Refuge (SLNWR) be...

  15. SAFOD Phase III Core Sampling and Data Management at the Gulf Coast Repository

    Directory of Open Access Journals (Sweden)

    David Lockner


    Full Text Available The San Andreas Fault Observatory at Depth (SAFODproject is yielding new insight into the San Andreas Fault (Zoback et al., 2010; Zoback et al., this issue. SAFOD drilling started in 2002 with a pilot hole, and proceeded with three phrases of drilling and coring during the summers of 2004, 2005, and 2007 (Fig. 1. One key component of theproject is curation, sampling, and documentation of SAFOD core usage at the Integrated Ocean Drilling Program’s (IODP Gulf Coast Repository (GCR at Texas A&M University. We present here the milestones accomplished over the past two years of sampling Phase III core at the GCR.

  16. Stalking the next Parkfield earthquake in Central California (United States)

    Kerr, R. A.


    Looking southeast from Middle Mountain toward Gold Hill, it is a subtle furrow in the grassy knolls of the Cholame Valley of California's Coast Range. To geophysicists, this 19-mile section of the San Andreas fault midway between San Francisco and Los Angeles is the most well understood, most intensely monitored fault in the world. As such, it is also the most likely place for American earthquake researchers to become earthquake predictors. 

  17. [Lou Andreas-Salome (1861-1937)--psychoanalytical and feministic contribution to understanding her biography]. (United States)

    Bramness, J G


    Lou (Louise) Andreas-Salomé's life and work has preoccupied many biographers. The interest may have be sparked by her liaisons with many of the greatest men of her time. She had an intimate relationship with Friedrich Nietzsche in a period of great change for him. She was Rainer Marie Rilke's mistress for several years. And she pursued a close friendship and working relationship with Sigmund Freud in the latter part of her life. But her significance goes beyond these associations. She was a celebrated novelist and essayist in her own right, with ten novels and more than 50 essays, also on psychoanalytical subjects. She has been viewed as femme fatale, opportunist, feminist, radical, liberal, but also as a significant contributor to psychoanalytical thought. There have been two biographical approaches: a psychoanalytical approach focusing on her loss of father-figures and later difficult relationships with famous men, and a feministic approach accusing psychoanalysts of not contributing to insight, but belittling Salomé's legitimate position. A fuller understanding may be obtained by integrating these two views.

  18. Andreas Vesalius' 500th Anniversary: Initial Integral Understanding of Voice Production. (United States)

    Brinkman, Romy J; Hage, J Joris


    Voice production relies on the integrated functioning of a three-part system: respiration, phonation and resonance, and articulation. To commemorate the 500th anniversary of the great anatomist Andreas Vesalius (1515-1564), we report on his understanding of this integral system. The text of Vesalius' masterpiece De Humani Corporis Fabrica Libri Septum and an eyewitness report of the public dissection of three corpses by Vesalius in Bologna, Italy, in 1540, were searched for references to the voice-producing anatomical structures and their function. We clustered the traced, separate parts for the first time. We found that Vesalius recognized the importance for voice production of many details of the respiratory system, the voice box, and various structures of resonance and articulation. He stressed that voice production was a cerebral function and extensively recorded the innervation of the voice-producing organs by the cranial nerves. Vesalius was the first to publicly record the concept of voice production as an integrated and cerebrally directed function of respiration, phonation and resonance, and articulation. In doing so nearly 500 years ago, he laid a firm basis for the understanding of the physiology of voice production and speech and its management as we know it today. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  19. Juan Valverde de Hamusco's unauthorized reproduction of a brain dissection by Andreas Vesalius. (United States)

    Lanska, Douglas J; Lanska, John R


    The objective of the present work is to examine images of the brain dissection by Flemish-born anatomist Andreas Vesalius (1514-1564) as originally represented in the Fabrica (1543), and later copied without Vesalius' permission by Spanish anatomist Juan Valverde de Hamusco (c1525-c1587) in Historia de la composicion del cuerpo humano (1556). Illustrations of the brain dissection in the Fabrica were obtained in digital form, resized, and arranged in a comparable montage to that presented by Valverde. Computer manipulations were used to assess image correspondence. The Valverde illustrations are approximately half the size and are mirror images of those in the Fabrica, but otherwise show the same dissection stages, and identical transverse brain levels and structures. The Valverde illustrations lack shadowing and show minor variations in perspective and fine details (e.g., branching pattern of the middle meningeal artery) from those in the Fabrica. Craftsmen under the direction of Valverde copied the woodcut prints in the Fabrica in close but approximate form by freehand engraving onto copper plates. Differences in the sizes of the images, and in perspective and fine detail, preclude direct tracing of images as the means of copying. Because engravings are in effect "flipped over" to make further prints, subsequent prints made from Valverde's copperplate engravings are mirror images of the prints in Vesalius' Fabrica.

  20. Andreas Vesalius' 500th anniversary: the initiation of hand and forearm myology. (United States)

    Brinkman, R J; Hage, J J


    Andreas Vesalius (1515-1564) was the first to market an illustrated text on the freshly dissected muscular anatomy of the human hand and forearm when he published his De Fabrica Corporis Humani Libri Septem, in 1543. To commemorate his 500th birthday, we searched the second of seven books composing De Fabrica, the annotated woodcut illustrations of De Fabrica, the Tabulae Sex, and Epitome, and an eyewitness report of a public dissection by Vesalius for references to the morphology and functions of these muscles. We found Vesalius to have recognized all currently distinguished muscles except the palmaris brevis and he noted occasional absence of some muscles. Generally, he limited the origin and insertion to bones, largely disregarding attachments to membranes and fascia. Functionally, he recorded the muscles as having a single vector and operating on only one joint. We conclude that Vesalius was nearly completely correct about the anatomy of the muscles of the forearm, but much less accurate about their function. 5. © The Author(s) 2015.

  1. The Andreas Vesalius woodblocks: a four hundred year journey from creation to destruction. (United States)

    Joffe, Stephen N; Buchanan, Veronica


    The purpose of this study was to trace the history of woodblocks created in 1542 by Andreas Vesalius (1514-1564). Carved by the Venetian workmen on pear tree boards, the woodblocks were used in the Basel printing of Vesalius' works De Humani Corporis Fabrica and Epitome from 1543, The China Root Epistle (1546), and the frontispiece of the Fabrica, the edition from 1555. The blocks remained with the printer Oporinus in Basel until his death in 1568 when they were sold to the Froben family. The woodblocks reappeared in 1706 in a publication by Maschenbauer and were subsequently used by Leveling in 1783. An incomplete set of woodblocks was moved from Inglostadt to Landshut and then to Munich where Roth in 1885 documented them. At the suggestion of an American physician, Samuel Lambert, the University of Munich found the "missing" woodblocks in the attic. This led Wiegand and the New York Academy of Medicine to publish the woodblocks in the Icones Anatomicae in 1934. The second edition frontispiece was returned to Louvain where it was destroyed by bombing in 1940 and all the remaining woodblocks were destroyed in Allied bombing between 1943 and 1945. Thus, the Vesalius woodblocks travelled a 400-year journey from their creation, through the use in eight publications with over 5000 prints and ended in their tragic destruction.

  2. Women, Sexuality and the Political Power of Pleasure (Susie Jolly, Andrea Cornwall y Kate Hawkins, Eds.

    Directory of Open Access Journals (Sweden)

    Laura Muelas de Ayala


    Full Text Available Como su propio título indica, Women, Sexuality and the Political Power of Pleasure es una obra en la que encontramos dinámicas, experiencias y prácticas para la movilización política y el empoderamiento de las mujeres a través del placer. Como apunta la antropóloga Andrea Cornwall, una de las editoras, el libro refleja la necesidad de traer al debate social y académico las iniciativas que se están llevando a cabo desde muy diversas latitudes, en las que el placer se convierte en el punto de partida desde el que explorar no solo las relaciones de las mujeres con su sexualidad, sino con el sistema normativo de género, la estructura social o las imposiciones familiares en cada contexto cultural. Es también una suerte de contestación hacia los programas de cooperación internacional que, al trabajar las distintas desigualdades de género, pasan por alto o invisibilizan la potencialidad que el placer puede imbuir en la construcción de nuevos escenarios sociales más igualitarios para las mujeres.

  3. Leonardo da Vinci and Andreas Vesalius; the shoulder girdle and the spine, a comparison. (United States)

    Ganseman, Y; Broos, P


    Leonardo Da Vinci and Andreas Vesalius were two important renaissance persons; Vesalius was a surgeon-anatomist who delivered innovative work on the study of the human body, Leonardo da Vinci was an artist who delivered strikingly accurate and beautiful drawings on the human body. Below we compare both masters with regard to their knowledge of the working of the muscles, their method and system of dissection and their system and presentation of the drawings. The investigation consisted of a comparison between both anatomists, in particular concerning their study on the shoulder girdle and spine, by reviewing their original work as well as already existing literature on this subject. The investigation led to the conclusion that the drawings mentioned meant a change in history, and were of high quality, centuries ahead of their time. Both were anatomists, both were revolutionary, only one changed history at the moment itself, while the other changed history centuries later. Leonardo has made beautiful drawings that are at a match with the drawings of today or are even better. Vesalius set the start for medicine as a science as it is until this day. Their lives differed as strongly as their impact. In the light of their time, the achievement they made was extraordinary.

  4. Characterization of the grafting copolymer EPDM-SAN; Caracterizacao do copolimero de enxertia EPDM-SAN

    Energy Technology Data Exchange (ETDEWEB)

    Turchette, Renato; Felisberti, Maria Isabel [Universidade Estadual de Campinas, SP (Brazil). Inst. de Quimica]. E-mail:


    This work aims the characterization of the grafting copolymer EPDM-SAN. This copolymer presents a fraction of free SAN chains, which was extracted by solubilization in chloroform followed of precipitation of the grafting copolymer EPDM-g-SAN in acetone. The EPDM-SAN and EPDM-g-SAN were characterized by {sup 13}C NMR, DSC, TGA and SEM. EPDM-SAN contain 23 wt% of free SAN and 77 wt% of EPDM-g-SAN. Both materials are heterogeneous and the thermal and thermo-oxidative degradation are independent of the composition. (author)

  5. Fault Analysis in Solar Photovoltaic Arrays (United States)

    Zhao, Ye

    Fault analysis in solar photovoltaic (PV) arrays is a fundamental task to increase reliability, efficiency and safety in PV systems. Conventional fault protection methods usually add fuses or circuit breakers in series with PV components. But these protection devices are only able to clear faults and isolate faulty circuits if they carry a large fault current. However, this research shows that faults in PV arrays may not be cleared by fuses under some fault scenarios, due to the current-limiting nature and non-linear output characteristics of PV arrays. First, this thesis introduces new simulation and analytic models that are suitable for fault analysis in PV arrays. Based on the simulation environment, this thesis studies a variety of typical faults in PV arrays, such as ground faults, line-line faults, and mismatch faults. The effect of a maximum power point tracker on fault current is discussed and shown to, at times, prevent the fault current protection devices to trip. A small-scale experimental PV benchmark system has been developed in Northeastern University to further validate the simulation conclusions. Additionally, this thesis examines two types of unique faults found in a PV array that have not been studied in the literature. One is a fault that occurs under low irradiance condition. The other is a fault evolution in a PV array during night-to-day transition. Our simulation and experimental results show that overcurrent protection devices are unable to clear the fault under "low irradiance" and "night-to-day transition". However, the overcurrent protection devices may work properly when the same PV fault occurs in daylight. As a result, a fault under "low irradiance" and "night-to-day transition" might be hidden in the PV array and become a potential hazard for system efficiency and reliability.

  6. Fault Management Guiding Principles (United States)

    Newhouse, Marilyn E.; Friberg, Kenneth H.; Fesq, Lorraine; Barley, Bryan


    Regardless of the mission type: deep space or low Earth orbit, robotic or human spaceflight, Fault Management (FM) is a critical aspect of NASA space missions. As the complexity of space missions grows, the complexity of supporting FM systems increase in turn. Data on recent NASA missions show that development of FM capabilities is a common driver for significant cost overruns late in the project development cycle. Efforts to understand the drivers behind these cost overruns, spearheaded by NASA's Science Mission Directorate (SMD), indicate that they are primarily caused by the growing complexity of FM systems and the lack of maturity of FM as an engineering discipline. NASA can and does develop FM systems that effectively protect mission functionality and assets. The cost growth results from a lack of FM planning and emphasis by project management, as well the maturity of FM as an engineering discipline, which lags behind the maturity of other engineering disciplines. As a step towards controlling the cost growth associated with FM development, SMD has commissioned a multi-institution team to develop a practitioner's handbook representing best practices for the end-to-end processes involved in engineering FM systems. While currently concentrating primarily on FM for science missions, the expectation is that this handbook will grow into a NASA-wide handbook, serving as a companion to the NASA Systems Engineering Handbook. This paper presents a snapshot of the principles that have been identified to guide FM development from cradle to grave. The principles range from considerations for integrating FM into the project and SE organizational structure, the relationship between FM designs and mission risk, and the use of the various tools of FM (e.g., redundancy) to meet the FM goal of protecting mission functionality and assets.

  7. Rectifier Fault Diagnosis and Fault Tolerance of a Doubly Fed Brushless Starter Generator


    Liwei Shi; Zhou Bo


    This paper presents a rectifier fault diagnosis method with wavelet packet analysis to improve the fault tolerant four-phase doubly fed brushless starter generator (DFBLSG) system reliability. The system components and fault tolerant principle of the high reliable DFBLSG are given. And the common fault of the rectifier is analyzed. The process of wavelet packet transforms fault detection/identification algorithm is introduced in detail. The fault tolerant performance and output voltage experi...

  8. Fault detection and isolation for complex system (United States)

    Jing, Chan Shi; Bayuaji, Luhur; Samad, R.; Mustafa, M.; Abdullah, N. R. H.; Zain, Z. M.; Pebrianti, Dwi


    Fault Detection and Isolation (FDI) is a method to monitor, identify, and pinpoint the type and location of system fault in a complex multiple input multiple output (MIMO) non-linear system. A two wheel robot is used as a complex system in this study. The aim of the research is to construct and design a Fault Detection and Isolation algorithm. The proposed method for the fault identification is using hybrid technique that combines Kalman filter and Artificial Neural Network (ANN). The Kalman filter is able to recognize the data from the sensors of the system and indicate the fault of the system in the sensor reading. Error prediction is based on the fault magnitude and the time occurrence of fault. Additionally, Artificial Neural Network (ANN) is another algorithm used to determine the type of fault and isolate the fault in the system.

  9. Weakness of serpentine minerals revealed by friction experiments under low and high temperature conditions. (United States)

    Harbord, C. W. A.; Tesei, T.; De Paola, N.; Collettini, C.; Scarlato, P.; Viti, C.


    Serpentines are important constituents of fault rocks and mélanges in a large variety of tectonic settings, including some major plate-boundary structures such as the San Andreas fault. Many of these structures are considered frictionally weak on geological and geophysical basis (i.e. µDurham University, UK). The sliding strength of lizardite and chrisotile/polygonal (the typical association in retrograde serpentinites and in several natural shear zones) is lower than previously reported (µ<0.2) and scarcely affected by temperature changes for T<200°. Interestingly, these results are in agreement with the fault strength inferred for the central segment of the San Andreas fault where abundant serpentinites are present. Our observations, together with field evidence from natural shear zones, suggest that serpentine-rich faults may significantly contribute to the weakness of major faults throughout the brittle upper crust.

  10. Marine and land active-source seismic imaging of mid-Miocene to Holocene-aged faulting near geothermal prospects at Pyramid Lake, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Eisses, A.; Kell, A.; Kent, G. [UNR; Driscoll, N. [UCSD; Karlin, R.; Baskin, R. [USGS; Louie, J. [UNR; Pullammanappallil, S. [Optim


    Amy Eisses, Annie Kell, Graham Kent, Neal Driscoll, Robert Karlin, Rob Baskin, John Louie, and Satish Pullammanappallil, 2011, Marine and land active-source seismic imaging of mid-Miocene to Holocene-aged faulting near geothermal prospects at Pyramid Lake, Nevada: presented at Geothermal Resources Council Annual Meeting, San Diego, Oct. 23-26.

  11. Where's the Hayward Fault? A Green Guide to the Fault (United States)

    Stoffer, Philip W.


    This report describes self-guided field trips to one of North America?s most dangerous earthquake faults?the Hayward Fault. Locations were chosen because of their easy access using mass transit and/or their significance relating to the natural and cultural history of the East Bay landscape. This field-trip guidebook was compiled to help commemorate the 140th anniversary of an estimated M 7.0 earthquake that occurred on the Hayward Fault at approximately 7:50 AM, October 21st, 1868. Although many reports and on-line resources have been compiled about the science and engineering associated with earthquakes on the Hayward Fault, this report has been prepared to serve as an outdoor guide to the fault for the interested public and for educators. The first chapter is a general overview of the geologic setting of the fault. This is followed by ten chapters of field trips to selected areas along the fault, or in the vicinity, where landscape, geologic, and man-made features that have relevance to understanding the nature of the fault and its earthquake history can be found. A glossary is provided to define and illustrate scientific term used throughout this guide. A ?green? theme helps conserve resources and promotes use of public transportation, where possible. Although access to all locations described in this guide is possible by car, alternative suggestions are provided. To help conserve paper, this guidebook is available on-line only; however, select pages or chapters (field trips) within this guide can be printed separately to take along on an excursion. The discussions in this paper highlight transportation alternatives to visit selected field trip locations. In some cases, combinations, such as a ride on BART and a bus, can be used instead of automobile transportation. For other locales, bicycles can be an alternative means of transportation. Transportation descriptions on selected pages are intended to help guide fieldtrip planners or participants choose trip

  12. Fault Recoverability Analysis via Cross-Gramian

    DEFF Research Database (Denmark)

    Shaker, Hamid Reza


    with feedback control. Fault recoverability provides important and useful information which could be used in analysis and design. However, computing fault recoverability is numerically expensive. In this paper, a new approach for computation of fault recoverability for bilinear systems is proposed......Engineering systems are vulnerable to different kinds of faults. Faults may compromise safety, cause sub-optimal operation and decline in performance if not preventing the whole system from functioning. Fault tolerant control (FTC) methods ensure that the system performance maintains within...

  13. An architecture for fault tolerant controllers

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob


    A general architecture for fault tolerant control is proposed. The architecture is based on the (primary) YJBK parameterization of all stabilizing compensators and uses the dual YJBK parameterization to quantify the performance of the fault tolerant system. The approach suggested can be applied...... for additive faults, parametric faults, and for system structural changes. The modeling for each of these fault classes is described. The method allows to design for passive as well as for active fault handling. Also, the related design method can be fitted either to guarantee stability or to achieve graceful...

  14. Fault Isolation for Shipboard Decision Support

    DEFF Research Database (Denmark)

    Lajic, Zoran; Blanke, Mogens; Nielsen, Ulrik Dam


    Fault detection and fault isolation for in-service decision support systems for marine surface vehicles will be presented in this paper. The stochastic wave elevation and the associated ship responses are modeled in the frequency domain. The paper takes as an example fault isolation of a containe......Fault detection and fault isolation for in-service decision support systems for marine surface vehicles will be presented in this paper. The stochastic wave elevation and the associated ship responses are modeled in the frequency domain. The paper takes as an example fault isolation...

  15. Polyphonie als mehrfach eingebettete Rede bei Flaubert. Andrea Landvogts Verbindung linguistischer und narratologischer Ansätze zu einer Typologie der Redewiedergabe [Andrea Landvogt: Discours cités. Eine äußerungs- und erzähltheoretisch fundierte Typologie der Redewiedergabe am Beispiel von Gustave Flaubert. Heidelberg 2011

    Directory of Open Access Journals (Sweden)

    Frauke Bode


    Full Text Available Rezension zu / Review of:Andrea Landvogt: Discours cités. Eine äußerungs- und erzähltheoretisch fundierte Typologie der Redewiedergabe am Beispiel von Gustave Flaubert. Heidelberg 2011. 

  16. Fault-tolerant Supervisory Control

    DEFF Research Database (Denmark)

    Izadi-Zamanabadi, Roozbeh

    of this work has been to develop and employ concepts and methods that are suitable for use in different automation processes, with applicability in various industrial fields. The requirements for high productivity and quality has resulted in employing additional instrumentation and use of more sophisticated...... control algorithms. The drawback is, however, that these control systems have become more vulnerable to even simple faults in instrumentation. On the other hand, due to cost-optimality requirements, an extensive use of hardware redundancy has been prohibited. Nevertheless, the dependency and availability...... could be increased through enhancing control systems' ability to on-line perform fault detection and reconfiguration when a fault occurs and before a safety system shuts-down the entire process. The main contributions of this research effort are development and experimentation with methodologies...

  17. San Language Development for Education in South Africa: The South African San Institute and the San Language Committees (United States)

    Pamo, Billies


    This article focuses on the 3 San communities in South Africa: the !Xun, the Khwe, and the [image omitted]Khomani San. The !Xun and Khwe communities are living in Platfontein, near Kimberley in the Northern Cape. The [image omitted]Khomani San community is living in Upington and in the southern Kalahari, which are also in the Northern Cape. This…

  18. San Jorge, el primer rejoneador


    Mandianes Castro, Manuel


    Las proezas de Jorge son una réplica de las de Santiago. Este luchó y venció las serpientes que habitaban Galicia para entrar allí y convertirla al cristianismo. San Jorge venció al monstruo del lago, y el rey y los habitantes de Silca se convirtieron a Cristo. Santiago ganó el nombre de Matamoros y de soldado de Cristo por excelencia porque, montado en su caballo blanco, venció en 1.000 batallas a los moros al frente de los cristianos. San Jorge venció a los sarracenos y conquistó Jerusalén ...

  19. El tratado de Andrea Pozzo y sus reflejos en los retablos en Minas Gerais

    Directory of Open Access Journals (Sweden)

    Aziz José de Oliveira Pedrosa


    Full Text Available A produção da talha dourada nas Minas Gerais do século18 foi possível pela pontual presença de artífices portugueses, que, de diversas regiões do Reino, migraram para o Brasil, diante das boas oportunidades de trabalhos de Arquitetura e ornamentação, nas igrejas que se erguiam na região de Minas. Muitos desses homens, entre arquitetos, entalhadores e demais profissionais que se dedicavam às artes e aos ofícios, foram os responsáveis pelos trabalhos de confecção da talha dourada, ornamentos necessários para deixar as igrejas com a devida decência para abrigar a fé de uma população em plena gênese de formação. Observe-se que foram, esses mesmos homens, os responsáveis por trazer as novidades artísticas vigentes na Europa Barroca para o interior das igrejas de Minas e aqui aclimatá-las, de acordo com as condições locais, tão divergentes do contexto europeu. Entretanto pouco se sabe sobre os modos pelos quais circularam na Capitania de Minas os modelos de Arquitetura e ornamentação, mas a descoberta de pequena biblioteca, sob a posse do entalhador José Coelho de Noronha, abre novos caminhos para debater o assunto, e traz a conhecimento reflexões de que, em Minas Gerais, durante o século 18, circularam tratados de Arquitetura. Assim, o presente artigo discute possibilidades de serem, alguns livros sob a posse de José Coelho de Noronha, os tratados de Arquitetura de Andrea Pozzo, que tiveram grande aceite e divulgação no mundo artístico europeu e, certamente, incidiram seus reflexos na Capitania de Minas.

  20. Vegetation - San Felipe Valley [ds172 (United States)

    California Department of Resources — This Vegetation Map of the San Felipe Valley Wildlife Area in San Diego County, California is based on vegetation samples collected in the field in 2002 and 2005 and...

  1. The San Bernabe power substation; La subestacion San Bernabe

    Energy Technology Data Exchange (ETDEWEB)

    Chavez Sanudo, Andres D. [Luz y Fuerza del Centro, Mexico, D. F. (Mexico)


    The first planning studies that gave rise to the San Bernabe substation go back to year 1985. The main circumstance that supports this decision is the gradual restriction for electric power generation that has been suffering the Miguel Aleman Hydro System, until its complete disappearance, to give priority to the potable water supply through the Cutzamala pumping system, that feeds in an important way Mexico City and the State of Mexico. In this document the author describes the construction project of the San Bernabe Substation; mention is made of the technological experiences obtained during the construction and its geographical location is shown, as well as the one line diagram of the same [Espanol] Los primeros estudios de planeacion que dieron origen a la subestacion San Bernabe se remontan al ano de 1985. La circunstancia principal que soporta esta decision es la restriccion paulatina para generar energia que ha venido experimentando el Sistema Hidroelectrico Miguel Aleman, hasta su desaparicion total, para dar prioridad al suministro de agua potable por medio del sistema de bombeo Cutzamala, que alimenta en forma importante a la Ciudad de Mexico y al Estado de Mexico. En este documento el autor describe el proyecto de construccion de la subestacion San Bernabe; se mencionan las experiencias tecnologicas obtenidas durante su construccion y se ilustra su ubicacion geografica, asi como un diagrama unifilar de la misma

  2. Fluid geochemistry of the San Vicente geothermal field (El Salvador)

    Energy Technology Data Exchange (ETDEWEB)

    Aiuppa, A.; Carapezza, M.L.; Parello, F. [University of Palermo (Italy). Istituto di Mineralogia


    The volcano Chichontepeque (San Vicente) is one of the nine recent volcanoes making up the El Salvador sector of the WNW-ESE-trending active Central American volcanic belt. Thermal activity is at present reduced to a few thermal springs and fumaroles. The most important manifestations (Agua Agria and Los Infernillos Ciegos) are boiling springs and fumaroles located on the northern slope of the volcano (850 m a.s.l.) along two radial faults. The application of geothermometric and geobarometric methods to the gases and thermal waters suggests that both thermal areas are linked to the identified 1100-1300 m reservoir, whose temperature (250{sup o}C), lateral extension and chemical composition, as resulting from this study, are of interest for industrial development. (author)

  3. Seafloor geology and benthic habitats, San Pedro Shelf, southern California (United States)

    Wong, Florence L.; Dartnell, Peter; Edwards, Brian D.; Phillips, Eleyne L.


    Seafloor samples, videography, still photography, and real-time descriptions of geologic and biologic constituents at or near the seafloor of the San Pedro Shelf, southern California, advance the study of natural and man-made processes on this coastal area off the metropolitan Los Angeles area. Multibeam echo-sounder data collected by the U.S. Geological Survey in 1998 and 1999 guided sampling and camera work in 2004 resulting in a new seafloor character map that shows possible benthic habitats in much higher resolution (4- and 16-m pixels) than previously available. The seafloor is characterized by primarily muddy sand and sand with outcrops of Miocene and Pliocene bedrock along the Palos Verdes Fault Zone. Observed benthic populations indicate low abiotic complexity, low biotic complexity, and low biotic coverage. The data are provided for use in geographic information systems (GIS).

  4. San Ignacio (La Tembladera) geothermal site, Departamento de Francisco Morazan, Honduras, Central America: Geological field report

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, M.J.; Eppler, D.; Heiken, G.; Flores, W.; Ramos, N.; Ritchie, A.


    The San Ignacio (La Tembladera) geothermal site is located on the north side of the Siria Valley, Departamento de Francisco Morazan, near the village of Barrosa. Hot springs are located along a northwest-trending fault scarp at the edge of the valley and along north-trending faults that cross the scarp. The rocks in the area are primarily Paleozoic metamorphic rocks, overlain by patches of Tertiary Padre Miguel Group tuffs and alluvial deposits. Movement probably occurred along several faults during latest Tertiary and possibly early Quaternary times. Four spring areas were mapped. Area 1, the largest, is associated with a sinter mound and consists of 40 spring groups. About half of the springs, aligned along a north-south trend, are boiling. Area 2 is a small sinter mound with several seeps. Area 3 consists of a group of hot and boiling springs aligned along a north-trending fault. The springs rise through fractured schists and a thin cover of alluvium. Area 4 is located at the intersection of several faults and includes one of the largest boiling springs in the area.

  5. 76 FR 45693 - Safety Zone; San Diego POPS Fireworks, San Diego, CA (United States)


    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; San Diego POPS Fireworks, San Diego, CA... temporary safety zone on the navigable waters of San Diego Bay in support of the San Diego POPS Fireworks..., participating vessels, and other vessels and users of the waterway during scheduled fireworks events. Persons...

  6. Fault-tolerant system for catastrophic faults in AMR sensors

    NARCIS (Netherlands)

    Zambrano Constantini, A.C.; Kerkhoff, Hans G.

    Anisotropic Magnetoresistance angle sensors are widely used in automotive applications considered to be safety-critical applications. Therefore dependability is an important requirement and fault-tolerant strategies must be used to guarantee the correct operation of the sensors even in case of

  7. Solar Dynamic Power System Fault Diagnosis (United States)

    Momoh, James A.; Dias, Lakshman G.


    The objective of this research is to conduct various fault simulation studies for diagnosing the type and location of faults in the power distribution system. Different types of faults are simulated at different locations within the distribution system and the faulted waveforms are monitored at measurable nodes such as at the output of the DDCU's. These fault signatures are processed using feature extractors such as FFT and wavelet transforms. The extracted features are fed to a clustering based neural network for training and subsequent testing using previously unseen data. Different load models consisting of constant impedance and constant power are used for the loads. Open circuit faults and short circuit faults are studied. It is concluded from present studies that using features extracted from wavelet transforms give better success rates during ANN testing. The trained ANN's are capable of diagnosing fault types and approximate locations in the solar dynamic power distribution system.

  8. Finite Fault Database (ANSS ComCat) (United States)

    U.S. Geological Survey, Department of the Interior — A Finite Fault is a modeled representation of the spatial extent, amplitude and duration of fault rupture (slip) of an earthquake, and is generated via the inversion...

  9. Quantifying Fault Networks on Alba Patera, Mars (United States)

    Wyrick, D. Y.; Ferrill, D. A.; Morris, A. P.; Sims, D. W.; Franklin, N. M.


    Newly developed terrestrial approaches were applied to martian fault networks to quantify the extent and degree of fault network connectivity. These techniques will provide key constraints for martian hydrological models.

  10. 27 CFR 9.157 - San Francisco Bay. (United States)


    ..., San Mateo, Santa Clara, Alameda, and Contra Costa, which border the San Francisco Bay. The area also... proceed along the San Francisco, San Mateo, and Santa Cruz County shoreline (across the Quadrangles of San... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false San Francisco Bay. 9.157...

  11. A summary of the active fault investigation in the extension sea area of Kikugawa fault and the Nishiyama fault , N-S direction fault in south west Japan (United States)

    Abe, S.


    In this study, we carried out two sets of active fault investigation by the request from Ministry of Education, Culture, Sports, Science and Technology in the sea area of the extension of Kikugawa fault and the Nishiyama fault. We want to clarify the five following matters about both active faults based on those results. (1)Fault continuity of the land and the sea. (2) The length of the active fault. (3) The division of the segment. (4) Activity characteristics. In this investigation, we carried out a digital single channel seismic reflection survey in the whole area of both active faults. In addition, a high-resolution multichannel seismic reflection survey was carried out to recognize the detailed structure of a shallow stratum. Furthermore, the sampling with the vibrocoring to get information of the sedimentation age was carried out. The reflection profile of both active faults was extremely clear. The characteristics of the lateral fault such as flower structure, the dispersion of the active fault were recognized. In addition, from analysis of the age of the stratum, it was recognized that the thickness of the sediment was extremely thin in Holocene epoch on the continental shelf in this sea area. It was confirmed that the Kikugawa fault extended to the offing than the existing results of research by a result of this investigation. In addition, the width of the active fault seems to become wide toward the offing while dispersing. At present, we think that we can divide Kikugawa fault into some segments based on the distribution form of the segment. About the Nishiyama fault, reflection profiles to show the existence of the active fault was acquired in the sea between Ooshima and Kyushu. From this result and topographical existing results of research in Ooshima, it is thought that Nishiyama fault and the Ooshima offing active fault are a series of structure. As for Ooshima offing active fault, the upheaval side changes, and a direction changes too. Therefore, we

  12. Stability of stacking faults in tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Dranova, Z.I.; Ksenofontov, V.A.; Kul' ko, V.B.; Mikhailovskii, I.M.


    The atomic configuration of planar lattice defects in tungsten was investigated by field-ion microscopy and thermal etching. Stable stacking faults were observed throughout the investigated temperature range 78--1700/sup 0/K. These faults were studied by field-ion microscopy and mathematical modeling methods. It was found that the existence of stacking faults in bcc crystals was not associated with the action of strong omnidirectional tensile stresses. The crystallographic characteristics of the faults were determined.

  13. Centennial ties: Harvey Cushing (1869-1939) and William Osler (1849-1919) on Andreas Vesalius (1514-1564). (United States)

    Toodayan, Nadeem


    Andreas Vesalius is often regarded as the founding father of modern anatomical study. The quincentennial anniversary of his birth - 31 December 2014 - has been very widely commemorated, and it is the purpose of this article to contrast these celebrations with what happened during the Vesalius quatercentenary year of 1914. More specifically, we look at how Vesalius was perceived a century ago by examining his influence on two of western medicine's most iconic gentlemen - Harvey Williams Cushing (1869-1939) and his larger than life mentor, Sir William Osler (1849-1919).

  14. Euroopas ei ole paremäärmuslus enam luuserite ideoloogia / Andrea Pető ; intervjueerinud Barbi Pilvre

    Index Scriptorium Estoniae

    Pető, Andrea


    Intervjuu Tallinnas Friedrich Eberti fondi kutsel viibinud Budapesti Kesk-Euroopa ülikooli professori Andrea Pető'ga, kes kaasautorina tähistas raamatu "Gender as Symbolic Glue. The Position and Role of Conservative and Far Right Parties In the Anti-Gender Mobilizations In Europe" eestikeelse tõlke "Sugu kui sümboolne liim" valmimist. Intervjuus avab ta soolise võrdõiguslikkuse, reproduktiivõiguste ja LGBTQ-vastaste liikumiste konservatiivset ja paremäärmuslikku tausta

  15. O diálogo Freud - Lou Andreas-Salomé sobre a feminilidade e o erotismo


    Lara Medeiros Borges Pereira


    Resumo: Este trabalho visa a estudar o diálogo Freud ¿ Lou Andreas-Salomé sobre a feminilidade e o erotismo. A problematização do feminino surge na obra de Freud a partir de 1905, em Três ensaios sobre a teoria da sexualidade, texto no qual ele introduz a ideia de que existe uma sexualidade infantil, trazendo à tona questões bastante polêmicas sobre a sexualidade de meninos e meninas. Com uma teoria baseada, a princípio, nas implicações da presença ou ausência de um elemento fálico real para ...

  16. First palaeoseismological data on the Santa Marta Fault System, Northern Colombia (United States)

    Idárraga, J.


    The Santa Marta Fault System (SMFS) is a NNW-striking major structural feature that controls the western foothills of the Sierra Nevada of Santa Marta (northern Colombia), the world's highest coastal relief. Morphotectonically, the SMFS exhibits an arrangement of parallel to subparallel fault traces. These traces are associated with a set of offset streams indicating a left-lateral component for displacement. NE-trending compressive structures as reverse faults (e.g. the Orihueca and San Pedro faults) and folds (the Fundación Anticline), and NW-trending distensive structures as normal faults are present too. These structures are consistent with a left-lateral shear zone striking NNW. An unlitified ruditic deposit with tectonic deformation crops out at the Riofrío site; this deposit consists of a series of debris slope layers linked to a deyection cone. The documented deformation in this outcrop is characterized by a tilting of the sequence to NE (against the direction of deposition) and by the presence of inverse faulting in which the coseismic displacement could have been distributed across distensive structures (normal faults and opened fractures). A magnitude (Mw) of 6.4 was calculated for the compressive event based on the displacement measured on the outcrop; this value corresponds to a minimum magnitude. Unfortunately, it has not been possible to date the deposits to constrain the tectonic events in time. The results of this research constitute the first data on the palaeoseismology of the SMFS, and are an important basis for future paleoseismic studies that allow calculating the seismic hazard of the region and giving an approximation of the Plio-Quaternary evolution of the South American northwestern corner.

  17. Pulverization Texturein Fault Damage Zones: A result of Implosion Damage or Dynamic Compressive Stresses? (United States)

    Rockwell, T. K.; Girty, G.; Whearty, J.; Mitchell, T. M.


    Micro-brecciation, or pulverization, is recognized as a fundamental component of the architecture and damage products of many large faults, although the precise mechanisms to produce this damage are debated, with both compressive and tensile mechanisms proposed. We characterized several sites along the San Jacinto fault, southern California, where the total depth of exhumation for the life history of the fault can be determined, to study the confining stresses required for pulverization. In basement rock near Anza, where exhumation is less than 100 m, granitic dikes injected into schist of the Burnt Valley Complex are pulverized out to several meters from the fault core, whereas the schist is brecciated at the macro-scale and contains narrow centimeter-thick seams of black cataclasite. Similar relationships are observed in Horse Canyon, which is exhumed about 400 m below a regional Tertiary erosion surface, where granitic dikes emplaced into schist are pulverized out to distances of several tens of meters from the fault core. These observations imply that very low confining stress is required for micro-brecciation in granitic rock. Unconsolidated sandstones (alluvial fan deposits) along the SJF in Rock House Canyon are undeformed where the deposits are exhumed by about 70 m, but show incipient pulverization (high-density, sub-grain cracking) at 120 m depth of exhumation. Cracks oriented perpendicular to the fault formed in individual quartz and feldspar grains out to a few meters from the fault core. These observations suggest that the confining stress required for onset of pulverization in unconsolidated deposits is on the order of 2-2.5 MPa. As the tensile strength of quartz is an order of magnitude higher than these confining stresses, the most likely mechanism that is producing this damage is dynamic compressive stresses during passage of the rupture front.

  18. Convair Astronautics, San Diego (California

    Directory of Open Access Journals (Sweden)

    Pereira & Luckmam, Arquitectos


    Full Text Available Este brillante y espectacular complejo industrial se ha creado especialmente para la investigación y fabricación de cohetes intercontinentales y vehículos del espacio de las Fuerzas Aéreas de los EE. UU., en las proximidades de San Diego y cerca del campo de pruebas de Sycamore Canyon.

  19. Continental Shelf Morphology and Stratigraphy Offshore San Onofre, CA: The Interplay Between Rates of Eustatic Change and Sediment Supply (United States)

    Klotsko, Shannon; Driscoll, Neal W.; Kent, Graham; Brothers, Daniel


    New high-resolution CHIRP seismic data acquired offshore San Onofre, southern California reveal that shelf sediment distribution and thickness are primarily controlled by eustatic sea level rise and sediment supply. Throughout the majority of the study region, a prominent abrasion platform and associated shoreline cutoff are observed in the subsurface from ~ 72 to 53 m below present sea level. These erosional features appear to have formed between Melt Water Pulse 1A and Melt Water Pulse 1B, when the rate of sea-level rise was lower. There are three distinct sedimentary units mapped above a regional angular unconformity interpreted to be the Holocene transgressive surface in the seismic data. Unit I, the deepest unit, is interpreted as a lag deposit that infills a topographic low associated with an abrasion platform. Unit I thins seaward by downlap and pinches out landward against the shoreline cutoff. Unit II is a mid-shelf lag deposit formed from shallower eroded material and thins seaward by downlap and landward by onlap. The youngest, Unit III, is interpreted to represent modern sediment deposition. Faults in the study area do not appear to offset the transgressive surface. The Newport Inglewood/Rose Canyon fault system is active in other regions to the south (e.g., La Jolla) where it offsets the transgressive surface and creates seafloor relief. Several shoals observed along the transgressive surface could record minor deformation due to fault activity in the study area. Nevertheless, our preferred interpretation is that the shoals are regions more resistant to erosion during marine transgression. The Cristianitos fault zone also causes a shoaling of the transgressive surface. This may be from resistant antecedent topography due to an early phase of compression on the fault. The Cristianitos fault zone was previously defined as a down-to-the-north normal fault, but the folding and faulting architecture imaged in the CHIRP data are more consistent with a

  20. Submarine Neotectonic Investigations of the Bahia Soledad Fault, off Northern Baja California Near the US - Mexico Border (United States)

    Anderson, K.; Lundsten, E. M.; Paull, C. K.; Caress, D. W.; Thomas, H. J.; Maier, K. L.; McGann, M.; Herguera, J. C.; Gwiazda, R.; Arregui, S.; Barrientos, L. A.


    The Monterey Bay Aquarium Research Institute (MBARI) conducted detailed surveys at selected sites on the seafloor along the Bahia Soledad Fault offshore of Northern Baja California, Mexico, during a two-ship expedition in the spring of 2015. The Bahia Soledad Fault is a NNW-trending strike-slip fault that is likely continuous with the San Diego Trough Fault offshore of San Diego, California. Constraining the style of deformation, continuity, and slip rate along this fault system is critical to characterizing the seismic hazards to the adjacent coastal areas extending from Los Angeles to Ensenada. Detailed morphologic surveys were conducted using an autonomous underwater vehicle (AUV) to provide ultra high-resolution multibeam bathymetry (vertical precision of 0.15 m and horizontal resolution of 1.0 m). The AUV also carried a 2-10 kHz chirp sub-bottom profiler and an Edgetech 110kHz and 410kHz sidescan. The two sites along the Bahia Soledad Fault each run ~6 km along the fault with ~1.8 km wide footprint. The resulting bathymetry shows these fault zones are marked with distinct lineations that are flanked by ~1 km long elongated ridges and depressions which are interpreted to be transpressional pop-up structures and transtensional pull-apart basins up to 100 m of relief. Offset seismic reflectors that extend to near the seafloor confirm that these lineations are fault scarps. The detailed bathymetric maps and sub-bottom profiles were used to locate key sites where deformed stratigraphic horizons along the fault are within 1.5 m of the seafloor. These areas were sampled using a remotely operated vehicle (ROV) equipped with a vibracoring system capable of collecting precisely located cores that are up to 1.5 m long. The coupled use of multibeam imagery and surgically-collected stratigraphic samples will enable to constrain the frequency and timing of recent movements on this fault which will be useful to incorporated into future seismic hazard assessment.

  1. Fault Detection for Nonlinear Systems

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, H.H.


    The paper describes a general method for designing fault detection and isolation (FDI) systems for nonlinear processes. For a rich class of nonlinear systems, a nonlinear FDI system can be designed using convex optimization procedures. The proposed method is a natural extension of methods based...

  2. Fault Tolerance Using Group Communication

    NARCIS (Netherlands)

    Kaashoek, M.F.; Tanenbaum, A.S.

    We propose group communication as an efficient mechanism to support fault tolerance. Our approach is based on an efficient reliable broadcast protocol that requires on average only two messages per broadcast. To illustrate our approach we will describe how the task bag model can be made

  3. Tsunamis and splay fault dynamics (United States)

    Wendt, J.; Oglesby, D.D.; Geist, E.L.


    The geometry of a fault system can have significant effects on tsunami generation, but most tsunami models to date have not investigated the dynamic processes that determine which path rupture will take in a complex fault system. To gain insight into this problem, we use the 3D finite element method to model the dynamics of a plate boundary/splay fault system. We use the resulting ground deformation as a time-dependent boundary condition for a 2D shallow-water hydrodynamic tsunami calculation. We find that if me stress distribution is homogeneous, rupture remains on the plate boundary thrust. When a barrier is introduced along the strike of the plate boundary thrust, rupture propagates to the splay faults, and produces a significantly larger tsunami man in the homogeneous case. The results have implications for the dynamics of megathrust earthquakes, and also suggest mat dynamic earthquake modeling may be a useful tool in tsunami researcn. Copyright 2009 by the American Geophysical Union.

  4. Fault detection using (PI) observers

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, J.; Shafai, B.

    The fault detection and isolation (FDI) problem in connection with Proportional Integral (PI) Observers is considered in this paper. A compact formulation of the FDI design problem using PI observers is given. An analysis of the FDI design problem is derived with respectt to the time domain...... properties. A method for design of PI observers applied to FDI is given....

  5. Triggered creep as a possible mechanism for delayed dynamic triggering of tremor and earthquakes (United States)

    Shelly, David R.; Peng, Zhigang; Hill, David P.; Aiken, Chastity


    The passage of radiating seismic waves generates transient stresses in the Earth's crust that can trigger slip on faults far away from the original earthquake source. The triggered fault slip is detectable in the form of earthquakes and seismic tremor. However, the significance of these triggered events remains controversial, in part because they often occur with some delay, long after the triggering stress has passed. Here we scrutinize the location and timing of tremor on the San Andreas fault between 2001 and 2010 in relation to distant earthquakes. We observe tremor on the San Andreas fault that is initiated by passing seismic waves, yet migrates along the fault at a much slower velocity than the radiating seismic waves. We suggest that the migrating tremor records triggered slow slip of the San Andreas fault as a propagating creep event. We find that the triggered tremor and fault creep can be initiated by distant earthquakes as small as magnitude 5.4 and can persist for several days after the seismic waves have passed. Our observations of prolonged tremor activity provide a clear example of the delayed dynamic triggering of seismic events. Fault creep has been shown to trigger earthquakes, and we therefore suggest that the dynamic triggering of prolonged fault creep could provide a mechanism for the delayed triggering of earthquakes. ?? 2011 Macmillan Publishers Limited. All rights reserved.

  6. Actuator Fault Detection and Diagnosis for Quadrotors

    NARCIS (Netherlands)

    Lu, P.; Van Kampen, E.J.; Yu, B.


    This paper presents a method for fault detection and diagnosis of actuator loss of effectiveness for a quadrotor helicopter. This paper not only considers the detection of the actuator loss of effectiveness faults, but also addresses the diagnosis of the faults. The detection and estimation of the

  7. High temperature superconducting fault current limiter (United States)

    Hull, John R.


    A fault current limiter (10) for an electrical circuit (14). The fault current limiter (10) includes a high temperature superconductor (12) in the electrical circuit (14). The high temperature superconductor (12) is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter (10).

  8. Engine gearbox fault diagnosis using empirical mode ...

    Indian Academy of Sciences (India)

    Kiran Vernekar

    A LabVIEW software Virtual Instrument (VI) program was developed to ... study. Artificial faults were generated at different locations of the bearing and they are bearing outer race, inner race, inner and outer race together fault and rolling element (ball) fault. ... validation information of original signal were decom- posed using ...

  9. On the "stacking fault" in copper

    NARCIS (Netherlands)

    Fransens, J.R.; Pleiter, F


    The results of a perturbed gamma-gamma angular correlations experiment on In-111 implanted into a properly cut single crystal of copper show that the defect known in the literature as "stacking fault" is not a planar faulted loop but a stacking fault tetrahedron with a size of 10-50 Angstrom.

  10. Active fault detection in MIMO systems

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad


    The focus in this paper is on active fault detection (AFD) for MIMO systems with parametric faults. The problem of design of auxiliary inputs with respect to detection of parametric faults is investigated. An analysis of the design of auxiliary inputs is given based on analytic transfer functions...

  11. Fault estimation - A standard problem approach

    DEFF Research Database (Denmark)

    Stoustrup, J.; Niemann, Hans Henrik


    This paper presents a range of optimization based approaches to fault diagnosis. A variety of fault diagnosis problems are reformulated in the so-called standard problem set-up introduced in the literature on robust control. Once the standard problem formulations are given, the fault diagnosis pr...

  12. The minimum scale of grooving on faults

    NARCIS (Netherlands)

    Candela, T.; Brodsky, E.E.


    At the field scale, nearly all fault surfaces contain grooves generated as one side of the fault slips past the other. Grooves are so common that they are one of the key indicators of principal slip surfaces. Here, we show that at sufficiently small scales, grooves do not exist on fault surfaces. A

  13. Fundamental problems in fault detection and identification

    DEFF Research Database (Denmark)

    Saberi, A.; Stoorvogel, A. A.; Sannuti, P.


    A number of different fundamental problems in fault detection and fault identification are formulated in this paper. The fundamental problems include exact, almost, generic and class-wise fault detection and identification. Necessary and sufficient conditions for the solvability of the fundamental...

  14. Exact, almost and delayed fault detection

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Saberi, Ali; Stoorvogel, Anton A.


    Considers the problem of fault detection and isolation while using zero or almost zero threshold. A number of different fault detection and isolation problems using exact or almost exact disturbance decoupling are formulated. Solvability conditions are given for the formulated design problems....... The l-step delayed fault detection problem is also considered for discrete-time systems....

  15. Fault diagnosis and fault-tolerant control based on adaptive control approach

    CERN Document Server

    Shen, Qikun; Shi, Peng


    This book provides recent theoretical developments in and practical applications of fault diagnosis and fault tolerant control for complex dynamical systems, including uncertain systems, linear and nonlinear systems. Combining adaptive control technique with other control methodologies, it investigates the problems of fault diagnosis and fault tolerant control for uncertain dynamic systems with or without time delay. As such, the book provides readers a solid understanding of fault diagnosis and fault tolerant control based on adaptive control technology. Given its depth and breadth, it is well suited for undergraduate and graduate courses on linear system theory, nonlinear system theory, fault diagnosis and fault tolerant control techniques. Further, it can be used as a reference source for academic research on fault diagnosis and fault tolerant control, and for postgraduates in the field of control theory and engineering. .

  16. ASTER Flyby of San Francisco (United States)


    The Advanced Spaceborne Thermal Emission and Reflection radiometer, ASTER, is an international project: the instrument was supplied by Japan's Ministry of International Trade and Industry. A joint US/Japan science team developed algorithms for science data products, and is validating instrument performance. With its 14 spectral bands, extremely high spatial resolution, and 15 meter along-track stereo capability, ASTER is the zoom lens of the Terra satellite. The primary mission goals are to characterize the Earth's surface; and to monitor dynamic events and processes that influence habitability at human scales. ASTER's monitoring and mapping capabilities are illustrated by this series of images of the San Francisco area. The visible and near infrared image reveals suspended sediment in the bays, vegetation health, and details of the urban environment. Flying over San Francisco (3.2MB) (high-res (18.3MB)), we see the downtown, and shadows of the large buildings. Past the Golden Gate Bridge and Alcatraz Island, we cross San Pablo Bay and enter Suisun Bay. Turning south, we fly over the Berkeley and Oakland Hills. Large salt evaporation ponds come into view at the south end of San Francisco Bay. We turn northward, and approach San Francisco Airport. Rather than landing and ending our flight, we see this is as only the beginning of a 6 year mission to better understand the habitability of the world on which we live. For more information: ASTER images through Visible Earth ASTER Web Site Image courtesy of MITI, ERSDAC, JAROS, and the U.S./Japan ASTER Science Team

  17. Fault Diagnosis in HVAC Chillers (United States)

    Choi, Kihoon; Namuru, Setu M.; Azam, Mohammad S.; Luo, Jianhui; Pattipati, Krishna R.; Patterson-Hine, Ann


    Modern buildings are being equipped with increasingly sophisticated power and control systems with substantial capabilities for monitoring and controlling the amenities. Operational problems associated with heating, ventilation, and air-conditioning (HVAC) systems plague many commercial buildings, often the result of degraded equipment, failed sensors, improper installation, poor maintenance, and improperly implemented controls. Most existing HVAC fault-diagnostic schemes are based on analytical models and knowledge bases. These schemes are adequate for generic systems. However, real-world systems significantly differ from the generic ones and necessitate modifications of the models and/or customization of the standard knowledge bases, which can be labor intensive. Data-driven techniques for fault detection and isolation (FDI) have a close relationship with pattern recognition, wherein one seeks to categorize the input-output data into normal or faulty classes. Owing to the simplicity and adaptability, customization of a data-driven FDI approach does not require in-depth knowledge of the HVAC system. It enables the building system operators to improve energy efficiency and maintain the desired comfort level at a reduced cost. In this article, we consider a data-driven approach for FDI of chillers in HVAC systems. To diagnose the faults of interest in the chiller, we employ multiway dynamic principal component analysis (MPCA), multiway partial least squares (MPLS), and support vector machines (SVMs). The simulation of a chiller under various fault conditions is conducted using a standard chiller simulator from the American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE). We validated our FDI scheme using experimental data obtained from different types of chiller faults.

  18. Fault-Tolerant Heat Exchanger (United States)

    Izenson, Michael G.; Crowley, Christopher J.


    A compact, lightweight heat exchanger has been designed to be fault-tolerant in the sense that a single-point leak would not cause mixing of heat-transfer fluids. This particular heat exchanger is intended to be part of the temperature-regulation system for habitable modules of the International Space Station and to function with water and ammonia as the heat-transfer fluids. The basic fault-tolerant design is adaptable to other heat-transfer fluids and heat exchangers for applications in which mixing of heat-transfer fluids would pose toxic, explosive, or other hazards: Examples could include fuel/air heat exchangers for thermal management on aircraft, process heat exchangers in the cryogenic industry, and heat exchangers used in chemical processing. The reason this heat exchanger can tolerate a single-point leak is that the heat-transfer fluids are everywhere separated by a vented volume and at least two seals. The combination of fault tolerance, compactness, and light weight is implemented in a unique heat-exchanger core configuration: Each fluid passage is entirely surrounded by a vented region bridged by solid structures through which heat is conducted between the fluids. Precise, proprietary fabrication techniques make it possible to manufacture the vented regions and heat-conducting structures with very small dimensions to obtain a very large coefficient of heat transfer between the two fluids. A large heat-transfer coefficient favors compact design by making it possible to use a relatively small core for a given heat-transfer rate. Calculations and experiments have shown that in most respects, the fault-tolerant heat exchanger can be expected to equal or exceed the performance of the non-fault-tolerant heat exchanger that it is intended to supplant (see table). The only significant disadvantages are a slight weight penalty and a small decrease in the mass-specific heat transfer.

  19. Robust Fault Diagnosis Design for Linear Multiagent Systems with Incipient Faults

    Directory of Open Access Journals (Sweden)

    Jingping Xia


    Full Text Available The design of a robust fault estimation observer is studied for linear multiagent systems subject to incipient faults. By considering the fact that incipient faults are in low-frequency domain, the fault estimation of such faults is proposed for discrete-time multiagent systems based on finite-frequency technique. Moreover, using the decomposition design, an equivalent conclusion is given. Simulation results of a numerical example are presented to demonstrate the effectiveness of the proposed techniques.

  20. ["... I shall never forget the gift by which you established yourself as friend in my life!" The letters of Lou Andreas-Salomé to Max Eitingon (1911-1933)]. (United States)

    Weber, Inge


    The correspondence between Andreas-Salomé and the Eitingons draws attention to their long-standing relation. The letters contained among the Eitingon papers in Jerusalem (81 items) were complemented by the much smaller set (5 items) held by the Lou Andreas-Salomé Archives in Göttingen. The material highlights for the first time Eitingon's role in securing Andreas-Salomé's access to the Berlin psychoanalytic association and for her entering psychoanalytic practice. In the 20s the relation between Andreas-Salomé and Mirra Eitingon intensified, based on their common Russian background. Several aspects featured in the letters are discussed in appendixes: the role of Russian language and habits; Max Nachmansohn, an analysand of Andreas-Salomé; her literary gift to Freud's 70th birthday; the dealing with fees in psychoanalysis.

  1. Hacia una arquitectura débil: Andrea Branzi y Gianni Vattimo

    Directory of Open Access Journals (Sweden)

    Pablo Martínez Capdevila


    Full Text Available Resumen Andrea Branzi es uno de los arquitectos que incorporan más tempranamente a su discurso la posmodernidad filosófica tal y como la formulan Jean-François Lyotard y, poco después, Gianni Vattimo. A  principios de los 80 el filósofo italiano propone el pensamiento débil como una filosofía consistente con este nuevo entorno que estaría marcado por  una condición a-histórica, un panorama fragmentado y babélico, y el  debilitamiento del ser. Branzi no sólo incorpora este nuevo marco intelectual a su discurso muy pronto, sino que es, seguramente, quien lo  traduce al campo arquitectónico de una forma más clara y explícita a  través muchos de sus escritos y, sobre todo, de sus "modelos de  urbanización débil”. Unas propuestas urbanas marcadas por la  fragmentación, la inestabilidad y la ligereza en las que se verifica un  proceso de disolución de la arquitectura perfectamente análogo a la  disolución del ser descrita por Vattimo: las construcciones abiertas y  adaptables de estas ciudades representan una especie de arquitectura atenuada que es al objeto arquitectónico canónico lo que el ser débil es al ser fuerte, metafísico en el discurso del filósofo. Sin embargo, a pesar de  la indudable adherencia de la obra y el discurso de Branzi al pensiero  debole de su compatriota, la relación entre ellos dista mucho de ser una pura incorporación por parte del arquitecto de un corpus que le era ajeno hasta ese momento. Por el contrario, resulta muy reveladora sobre los  invariantes que Branzi ha mantenido, obstinadamente, a lo largo de su  larga trayectoria y, más en general, sobre el modo en el que muchos  arquitectos se relacionan con su entorno cultural.

  2. Mesoscopic Structural Observations of Cores from the Chelungpu Fault System, Taiwan Chelungpu-Fault Drilling Project Hole-A, Taiwan

    Directory of Open Access Journals (Sweden)

    Hiroki Sone


    Full Text Available Structural characteristics of fault rocks distributed within major fault zones provide basic information in understanding the physical aspects of faulting. Mesoscopic structural observations of the drilledcores from Taiwan Chelungpu-fault Drilling Project Hole-A are reported in this article to describe and reveal the distribution of fault rocks within the Chelungpu Fault System.

  3. Numerical modelling of the mechanical and fluid flow properties of fault zones - Implications for fault seal analysis

    NARCIS (Netherlands)

    Heege, J.H. ter; Wassing, B.B.T.; Giger, S.B.; Clennell, M.B.


    Existing fault seal algorithms are based on fault zone composition and fault slip (e.g., shale gouge ratio), or on fault orientations within the contemporary stress field (e.g., slip tendency). In this study, we aim to develop improved fault seal algorithms that account for differences in fault zone

  4. Synthesis of Fault-Tolerant Embedded Systems

    DEFF Research Database (Denmark)

    Eles, Petru; Izosimov, Viacheslav; Pop, Paul


    This work addresses the issue of design optimization for fault- tolerant hard real-time systems. In particular, our focus is on the handling of transient faults using both checkpointing with rollback recovery and active replication. Fault tolerant schedules are generated based on a conditional...... process graph representation. The formulated system synthesis approaches decide the assignment of fault-tolerance policies to processes, the optimal placement of checkpoints and the mapping of processes to processors, such that multiple transient faults are tolerated, transparency requirements...

  5. Un artista cortesano en la Barcelona de Carlos III de Austria: apuntes prosopográficos sobre Andrea Vaccaro II

    Directory of Open Access Journals (Sweden)

    Quirós Rosado, Roberto


    Full Text Available At the beginning of the 18th century Barcelona was a principal entry point for the introduction of Italian courtly culture in Spain during the brief reign of Carlos III of Habsburg. This study analyzes the presence of the little-known Neapolitan painter Andrea Vaccaro II in Cataluña, and his connections with the Royal Chamber and the Spanish Habsburg ministry, as well as the concession of offices in Reame as payment for palace services.La diversidad de focos de introducción de la cultura de corte italiana en los inicios del siglo XVIII español obliga a indagar en la circulación de artistas napolitanos en la Barcelona de Carlos III de Austria. Bajo esta premisa, en el estudio se analiza la estancia catalana del desconocido pintor napolitano Andrea Vaccaro II, sus lazos con la Real Cámara y el ministerio español del monarca Habsburgo, así como la concesión de oficios en los tribunales de Nápoles como pago por servicios en palacio.

  6. [Andreas Vesalius: his rich imagination and colorful detail account in his book: 'Research of the anatomical observations of Gabriel Falloppius']. (United States)

    Gilias, Guy


    In a long letter, Andreas Vesalius reacts to the comments made by Gabriel Falloppius to his work 'De Humani Corporis Fabrica'. In this letter, he proves Falloppius wrong in a number of assertions and corrects him on more than one occasion. In doing so, Vesalius as a renaissance humanist uses a classic Latin language with long elegant sentences in the style of the old Roman orator Cicero. Remarkably interesting is the fact that this whole argumentation is spiced with comparisons and examples from daily life. To make it clear to the reader what a certain part of the skeleton looks like, he compares this part with an object everybody knows. All parts of the human body are depicted in such an almost graphic way that even an interested reader without any medical or anatomic education can picture them. And Vesalius is very creative in doing so, an artist as it were with a very rich imagination. Moreover, it's remarkable how the famous anatomist manages to put himself on the level of any ordinary person, using comparative images on that level. This last work of Vesalius, which he himself considers to be a supplement to his De Humani Corporis Fabrica, deserves special attention, not only because it illustrates the scientific evolution of the anatomist Vesalius, but also because it offers an insight in the psychology of that fascinating scientist Andreas Vesalius.

  7. ESR dating of the fault rocks

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee Kwon [Kangwon National Univ., Chuncheon (Korea, Republic of)


    Past movement on faults can be dated by measurement of the intensity of ESR signals in quartz. These signals are reset by local lattice deformation and local frictional heating on grain contacts at the time of fault movement. The ESR signals then grow back as a result of bombardment by ionizing radiation from surrounding rocks. The age is obtained from the ratio of the equivalent dose, needed to produce the observed signal, to the dose rate. Fine grains are more completely reset during faulting, and a plot of age vs, grain size shows a plateau for grains below critical size : these grains are presumed to have been completely zeroed by the last fault activity. We carried out ESR dating of fault rocks collected near the Ulzin nuclear reactor. ESR signals of quartz grains separated from fault rocks collected from the E-W trend fault are saturated. This indicates that the last movement of these faults had occurred before the quaternary period. ESR dates from the NW trend faults range from 300ka to 700ka. On the other hand, ESR date of the NS trend fault is about 50ka. Results of this research suggest that long-term cyclic fault activity near the Ulzin nuclear reactor continued into the pleistocene.

  8. A Quaternary fault database for central Asia (United States)

    Mohadjer, Solmaz; Ehlers, Todd Alan; Bendick, Rebecca; Stübner, Konstanze; Strube, Timo


    Earthquakes represent the highest risk in terms of potential loss of lives and economic damage for central Asian countries. Knowledge of fault location and behavior is essential in calculating and mapping seismic hazard. Previous efforts in compiling fault information for central Asia have generated a large amount of data that are published in limited-access journals with no digital maps publicly available, or are limited in their description of important fault parameters such as slip rates. This study builds on previous work by improving access to fault information through a web-based interactive map and an online database with search capabilities that allow users to organize data by different fields. The data presented in this compilation include fault location, its geographic, seismic, and structural characteristics, short descriptions, narrative comments, and references to peer-reviewed publications. The interactive map displays 1196 fault traces and 34 000 earthquake locations on a shaded-relief map. The online database contains attributes for 123 faults mentioned in the literature, with Quaternary and geodetic slip rates reported for 38 and 26 faults respectively, and earthquake history reported for 39 faults. All data are accessible for viewing and download via This work has implications for seismic hazard studies in central Asia as it summarizes important fault parameters, and can reduce earthquake risk by enhancing public access to information. It also allows scientists and hazard assessment teams to identify structures and regions where data gaps exist and future investigations are needed.

  9. Tool for Viewing Faults Under Terrain (United States)

    Siegel, Herbert, L.; Li, P. Peggy


    Multi Surface Light Table (MSLT) is an interactive software tool that was developed in support of the QuakeSim project, which has created an earthquake- fault database and a set of earthquake- simulation software tools. MSLT visualizes the three-dimensional geometries of faults embedded below the terrain and animates time-varying simulations of stress and slip. The fault segments, represented as rectangular surfaces at dip angles, are organized into collections, that is, faults. An interface built into MSLT queries and retrieves fault definitions from the QuakeSim fault database. MSLT also reads time-varying output from one of the QuakeSim simulation tools, called "Virtual California." Stress intensity is represented by variations in color. Slips are represented by directional indicators on the fault segments. The magnitudes of the slips are represented by the duration of the directional indicators in time. The interactive controls in MSLT provide a virtual track-ball, pan and zoom, translucency adjustment, simulation playback, and simulation movie capture. In addition, geographical information on the fault segments and faults is displayed on text windows. Because of the extensive viewing controls, faults can be seen in relation to one another, and to the terrain. These relations can be realized in simulations. Correlated slips in parallel faults are visible in the playback of Virtual California simulations.

  10. Rule-based fault diagnosis of hall sensors and fault-tolerant control of PMSM (United States)

    Song, Ziyou; Li, Jianqiu; Ouyang, Minggao; Gu, Jing; Feng, Xuning; Lu, Dongbin


    Hall sensor is widely used for estimating rotor phase of permanent magnet synchronous motor(PMSM). And rotor position is an essential parameter of PMSM control algorithm, hence it is very dangerous if Hall senor faults occur. But there is scarcely any research focusing on fault diagnosis and fault-tolerant control of Hall sensor used in PMSM. From this standpoint, the Hall sensor faults which may occur during the PMSM operating are theoretically analyzed. According to the analysis results, the fault diagnosis algorithm of Hall sensor, which is based on three rules, is proposed to classify the fault phenomena accurately. The rotor phase estimation algorithms, based on one or two Hall sensor(s), are initialized to engender the fault-tolerant control algorithm. The fault diagnosis algorithm can detect 60 Hall fault phenomena in total as well as all detections can be fulfilled in 1/138 rotor rotation period. The fault-tolerant control algorithm can achieve a smooth torque production which means the same control effect as normal control mode (with three Hall sensors). Finally, the PMSM bench test verifies the accuracy and rapidity of fault diagnosis and fault-tolerant control strategies. The fault diagnosis algorithm can detect all Hall sensor faults promptly and fault-tolerant control algorithm allows the PMSM to face failure conditions of one or two Hall sensor(s). In addition, the transitions between health-control and fault-tolerant control conditions are smooth without any additional noise and harshness. Proposed algorithms can deal with the Hall sensor faults of PMSM in real applications, and can be provided to realize the fault diagnosis and fault-tolerant control of PMSM.

  11. Active fault diagnosis by controller modification

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, Hans Henrik


    Two active fault diagnosis methods for additive or parametric faults are proposed. Both methods are based on controller reconfiguration rather than on requiring an exogenous excitation signal, as it is otherwise common in active fault diagnosis. For the first method, it is assumed that the system...... in a way that guarantees the continuity of transition and global stability using a recent result on observer parameterization. An illustrative example inspired by a field study of a drag racing vehicle is given. For the second method, an active fault diagnosis method for parametric faults is proposed...... considered is controlled by an observer-based controller. The method is then based on a number of alternate observers, each designed to be sensitive to one or more additive faults. Periodically, the observer part of the controller is changed into the sequence of fault sensitive observers. This is done...

  12. Diagnosis and Fault-tolerant Control

    DEFF Research Database (Denmark)

    Blanke, Mogens; Kinnaert, Michel; Lunze, Jan

    The book presents effective model-based analysis and design methods for fault diagnosis and fault-tolerant control. Architectural and structural models are used to analyse the propagation of the fault through the process, to test the fault detectability and to find the redundancies in the process...... the applicability of the presented methods. The theoretical results are illustrated by two running examples which are used throughout the book. The book addresses engineering students, engineers in industry and researchers who wish to get a survey over the variety of approaches to process diagnosis and fault...... that can be used to ensure fault tolerance. Design methods for diagnostic systems and fault-tolerant controllers are presented for processes that are described by analytical models, by discrete-event models or that can be dealt with as quantised systems. Four case studies on pilot processes show...

  13. Arcos triunfales de San Petersburgo


    Kurz Muñiz, Juan Albert; Gordo, Carmen María


    Se conmemora el tricentenario de la ciudad de San Petersburgo, ciudad que nos ha dejado grandiosos monumentos a lo largo de su historia. La importancia de los arcos triunfales, exponentes máximos que reglejan las victorias acaecidas, con un refinamiento y belleza occidental. Erigidos durante los reinados de Pedro I el Grande y Catalina II, monarcas ilustrados que supieron abrir a Rusia hacia la modernidad.

  14. Inverter Ground Fault Overvoltage Testing

    Energy Technology Data Exchange (ETDEWEB)

    Hoke, Andy [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Nelson, Austin [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Chakraborty, Sudipta [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Chebahtah, Justin [SolarCity Corporation, San Mateo, CA (United States); Wang, Trudie [SolarCity Corporation, San Mateo, CA (United States); McCarty, Michael [SolarCity Corporation, San Mateo, CA (United States)


    This report describes testing conducted at NREL to determine the duration and magnitude of transient overvoltages created by several commercial PV inverters during ground fault conditions. For this work, a test plan developed by the Forum on Inverter Grid Integration Issues (FIGII) has been implemented in a custom test setup at NREL. Load rejection overvoltage test results were reported previously in a separate technical report.

  15. Ground Motion Simulations of Scenario Earthquake Ruptures of the Hayward Fault (United States)

    Aagaard, B.; Graves, R.; Larsen, S.; Ma, S.; Rodgers, A.; Brocher, T.; Graymer, R.; Harris, R.; Lienkaemper, J.; Ponce, D.; Schwartz, D.; Simpson, R.; Spudich, P.; Dreger, D.; Petersson, A.; Boatwright, J.


    We compute ground motions in the San Francisco Bay area for a suite of 35 magnitude 6.7--7.2 scenario earthquake ruptures involving the Hayward fault. The suite of scenarios encompasses variability in rupture length, hypocenter, distribution of slip, rupture speed, and rise time. The five rupture lengths include the Hayward fault and portions thereof, as well as combined rupture of the Hayward and Rodgers Creek faults and the Hayward and Calaveras faults. For most rupture lengths, we consider three hypocenters, yielding north-to-south rupture, bilateral rupture, and south-to-north rupture. We also consider multiple random realizations of the slip distribution, accounting for creeping patches (Funning et al., 2007) either through simple assumptions about how creep reduces coseismic slip or a slip-predictable approach. The kinematic rupture models include local variations in rupture speed and use a ray-tracing algorithm to propagate the rupture front. Although we are not attempting to simulate the 1868 Hayward fault earthquake in detail, a few of the scenarios are designed to have source parameters that might be similar to this event. This collaborative effort involves four modeling groups, using different wave propagation codes and domains of various sizes and resolutions, computing long-period (T > 1--2 s) or broadband (T > 0.1 s) synthetic ground motions for overlapping subsets of the suite of scenarios. The simulations incorporate the 3-D geologic structure as described by the USGS 3-D Geologic Model (Jachens et al., 2006; Watt et al., 2007) and USGS Bay Area Velocity Model (Brocher et al., 2007). The simulations illustrate the dramatic increase in intensity of shaking for a magnitude 7.0 bilateral rupture of the entire Hayward fault compared with a magnitude 6.8 bilateral rupture of the southern two-thirds of the fault; the area subjected to shaking stronger than MMI VII increases from about 10% to more than 40% of the San Francisco Bay urban area. For a given

  16. New fault tolerant matrix converter

    Energy Technology Data Exchange (ETDEWEB)

    Ibarra, Edorta; Andreu, Jon; Kortabarria, Inigo; Ormaetxea, Enekoitz; Alegria, Inigo Martinez de; Martin, Jose Luis [Department of Electronics and Telecommunications, University of the Basque Country, Alameda de Urquijo s/n, E-48013 Bilbao (Spain); Ibanez, Pedro [TECNALIA, Energy Unit, Parque Tecnologico de Zamudio, E-48170 Bizkaia (Spain)


    The matrix converter (MC) presents a promising topology that will have to overcome certain barriers (protection systems, durability, the development of converters for real applications, etc.) in order to gain a foothold in the industry. In some applications, where continuous operation must be insured in the case of a system failure, improved reliability of the converter is of particular importance. In this sense, this article focuses on the study of a fault tolerant MC. The fault tolerance of a converter is characterized by its total or partial response in the case of a breakage of any of its components. Taking into consideration that virtually no work has been done on fault tolerant MCs, this paper describes the most important studies in this area. Moreover, a new method is proposed for detecting the breakage of MC semiconductors. Likewise, a new variation of SVM modulation with failure tolerance capacity is presented. This guarantees the continuous operation of the converter and the pseudo-optimum control of a PMSM. This paper also proposes a novel MC topology, which allows the flexible reconfiguration of this converter, when one or several of its semiconductors are damaged. In this way, the MC can continue operating at 100% of its performance without having to double its resources. In this way, it can be said that the solution described in this article represents a step forward towards the development of reliable matrix converters for real applications. (author)

  17. Fault tolerant operation of switched reluctance machine (United States)

    Wang, Wei

    The energy crisis and environmental challenges have driven industry towards more energy efficient solutions. With nearly 60% of electricity consumed by various electric machines in industry sector, advancement in the efficiency of the electric drive system is of vital importance. Adjustable speed drive system (ASDS) provides excellent speed regulation and dynamic performance as well as dramatically improved system efficiency compared with conventional motors without electronics drives. Industry has witnessed tremendous grow in ASDS applications not only as a driving force but also as an electric auxiliary system for replacing bulky and low efficiency auxiliary hydraulic and mechanical systems. With the vast penetration of ASDS, its fault tolerant operation capability is more widely recognized as an important feature of drive performance especially for aerospace, automotive applications and other industrial drive applications demanding high reliability. The Switched Reluctance Machine (SRM), a low cost, highly reliable electric machine with fault tolerant operation capability, has drawn substantial attention in the past three decades. Nevertheless, SRM is not free of fault. Certain faults such as converter faults, sensor faults, winding shorts, eccentricity and position sensor faults are commonly shared among all ASDS. In this dissertation, a thorough understanding of various faults and their influence on transient and steady state performance of SRM is developed via simulation and experimental study, providing necessary knowledge for fault detection and post fault management. Lumped parameter models are established for fast real time simulation and drive control. Based on the behavior of the faults, a fault detection scheme is developed for the purpose of fast and reliable fault diagnosis. In order to improve the SRM power and torque capacity under faults, the maximum torque per ampere excitation are conceptualized and validated through theoretical analysis and

  18. Cataclastic faults along the SEMP fault system (Eastern Alps, Austria) — A contribution to fault zone evolution, internal structure and paleo-stresses (United States)

    Hausegger, Stefan; Kurz, Walter


    In this study three different sites along the ENE-trending, sinistral Salzach-Ennstal-Mariazell-Puchberg [SEMP] fault zone were investigated with respect to brittle fault zone evolution and fault re-activation. All sites crop out in Triassic carbonates (Ladinian Wetterstein limestone/-dolomite). Simultaneously (re-) activated faults were investigated with focus on fault-slip data and structural inventory of each individual fault zone. Configuration of (internal) structural elements, fault core thickness, strike direction and slip sense in addition to particle analysis of fault core cataclasites add up to three different fault types (Fault Types I, II and III). Fault Type I is classified by a complex internal fault core structure with thicknesses up to several 10s of meters and generally evolve in a strike direction of maximum shear stress (τmax). Type II faults, characterized by cataclastic fault cores with thicknesses up to 1 m, as well as Type III faults (thin solitary cataclastic layers) evolve sub-parallel to the main fault direction and in orientation according to R, R' or X shear fractures with variable (σn/τ) ratio. Progressive development from Type III to Type II and Type I faults is consistent with increasing displacement and increasing fault core width. Fault type classification and related paleostress analysis provide evidence from field observation compared to theoretical and analog models of Mohr-Coulomb fracture evolution.

  19. Estimating Earthquake Hazards in the San Pedro Shelf Region, Southern California (United States)

    Baher, S.; Fuis, G.; Normark, W. R.; Sliter, R.


    The San Pedro Shelf (SPS) region of the inner California Borderland offshore southern California poses a significant seismic hazard to the contiguous Los Angeles Area, as a consequence of late Cenozoic compressional reactivation of mid-Cenozoic extensional faults. The extent of the hazard, however, is poorly understood because of the complexity of fault geometries and uncertainties in earthquake locations. The major faults in the region include the Palos Verdes, THUMS Huntington Beach and the Newport-Inglewood fault zones. We report here the analysis and interpretation of wide-angle seismic-reflection and refraction data recorded as part of the Los Angeles Region Seismic Experiment line 1 (LARSE 1), multichannel seismic (MCS) reflection data obtained by the USGS (1998-2000) and industry borehole stratigraphy. The onshore-offshore velocity model, which is based on forward modeling of the refracted P-wave arrival times, is used to depth migrate the LARSE 1 section. Borehole stratigraphy allows correlation of the onshore and offshore velocity models because state regulations prevent collection of deep-penetration acoustic data nearshore (within 3 mi.). Our refraction study is an extension of ten Brink et al., 2000 tomographic inversion of LARSE I data. They found high velocities (> 6 km/sec) at about ~3.5 km depth from the Catalina Fault (CF) to the SPS. We find these velocities, shallower (around 2 km depth) beneath the Catalina Ridge (CR) and SPS, but at a depth 2.5-3.0 km elsewhere in the study region. This change in velocity structure can provide additional constraints for the tectonic processes of this region. The structural horizons observed in the LARSE 1 reflection data are tied to adjacent MCS lines. We find localized folding and faulting at depth (~2 km) southwest of the CR and on the SPS slope. Quasi-laminar beds, possible of pelagic origin follow the contours of earlier folded (wavelength ~1 km) and faulted Cenozoic sedimentary and volcanic rocks. Depth to

  20. Fault Diagnosis and Fault Tolerant Control with Application on a Wind Turbine Low Speed Shaft Encoder

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Sardi, Hector Eloy Sanchez; Escobet, Teressa


    . This sensor has to be correct as blade pitch actions should be different at different azimuth angle as the wind speed varies within the rotor field due to different phenomena. A scheme detecting faults in this sensor has previously been designed for the application of a high end fault diagnosis and fault...... tolerant control of wind turbines using a benchmark model. In this paper, the fault diagnosis scheme is improved and integrated with a fault accommodation scheme which enables and disables the individual pitch algorithm based on the fault detection. In this way, the blade and tower loads are not increased...

  1. 500th birthday of Andreas Vesalius, the founder of modern anatomy: "vivitur ingenio, caetera mortis erunt" ("genius lives on, all else is mortal"). (United States)

    Hadzic, Admir; Sadeghi, Neda; Vandepitte, Catherine; Vandepitte, Walter; Van de Velde, Marc; Hadzic, Alen; Van Robays, Johan; Heylen, Rene; Herijgers, Paul; Vloka, Caroline; Van Zundert, Jan


    It is often said that regional anesthesia is the practice of applied anatomy. Therefore, it is fitting that on the occasion of his 500th birthday, we celebrate the life and work of the brilliant Flemish anatomist, Andreas Vesalius (1514-1564), the founder of modern anatomy.

  2. Leuven: birthplace of modern skeletology, thanks to Andreas Vesalius, with the help of Gemma Frisius, his friend and fellow-physician. (United States)

    Biesbrouck, M; Steeno, O


    The skeleton-making technique of Andreas Vesalius is described and is compared with that of others. An overview is added of the skeletons he constructed himself. The significance of his friend Gemma Frisius is discussed as well as the translations of the chapter of this technique in the De humani corporis fabrica.

  3. Fault Diagnosis and Fault-tolerant Control of Modular Multi-level Converter High-voltage DC System

    DEFF Research Database (Denmark)

    Liu, Hui; Ma, Ke; Wang, Chao


    device fault, DC line faults as well as AC grid faults. Special attention is given to the comparison of the corresponding fault diagnosis and fault-tolerant control approaches. Further, focus is dedicated to control/protection strategies and topologies with fault ride-though capability for MMC...... of failures and lower the reliability of the MMC-HVDC system. Therefore, research on the fault diagnosis and fault-tolerant control of MMC-HVDC system is of great significance in order to enhance the reliability of the system. This paper provides a comprehensive review of fault diagnosis and fault handling...... strategies of MMC-HVDC systems for the most common faults happened in MMC-HVDC systems covering MMC faults, DC side faults as well as AC side faults. An important part of this paper is devoted to a discussion of the vulnerable spots as well as failure mechanism of the MMC-HVDC system covering switching...

  4. The art of Joseph Beuys and Vision Andreas Huyssen in Postmodernity A arte de Joseph Beuys e a visão de Andreas Huyssen na pós-modernidade

    Directory of Open Access Journals (Sweden)

    Lívia Garcez de Oliveira Padilha


    Full Text Available This article aims do present reflections on art in post-modernity, which encourages a reading of the ambivalence between the technique and aesthetics. We focus the environmentalist work of artist Joseph Beuys and the critical German essayist Andreas Huyssen and the paradoxical thinking of vanguard and mass culture. Is it possible to think like that in a dualist way? Or we can see a shift in sensitivity towards what touches us by affection? We believe, nevertheless, that exists a permanent state of artistic tension which stimulates a more relativistic than categorical culture in the XXI century.Este artigo tem como objetivo apresentar reflexões sobre a arte na pós-modernidade - que estimula uma leitura da ambivalência entre técnica e estética - por meio de duas obras “ambientalistas” do artista plástico Joseph Beuys e do olhar crítico, mas de cunho compreensivo, do ensaísta alemão Andreas Huyssen. O enfoque é o paradoxo entre a arte dita culta ou de vanguarda (? e a sua possível massificação (?. Estas duas expressões – vanguarda e massificação - ainda se sustentam na paisagem pós-moderna? Ou percebe-se um redirecionamento da sensibilidade em direção àquilo que nos toca pela afetividade? Consideramos, por meio da fenomenologia, que se enfrenta, em tempos pós-modernos, um permanente estado de tensionamento artístico, o que estimula uma visão mais relativista do que categórica da cultura no século XXI.

  5. L’apparato decorativo delle Metamorfosi di Giovanni Andrea dell’Anguillara. Le serie iconografiche cinquecentesche / The illustrations of Ovidio’s Metamorphoses by Giovanni Andrea dell’Anguillara. The iconographic series of the 16th Century

    Directory of Open Access Journals (Sweden)

    Francesca Casamassima


    Full Text Available Le illustrazioni presenti nelle edizioni cinquecentesche delle Metamorfosi di Ovidio, tradotte da Giovanni Andrea dell’Anguillara, non sono mai state oggetto di uno studio approfondito e dettagliato. L’articolo propone l’analisi iconografica di tutte le serie che accompagnano la traduzione ed opera un accurato confronto tra di esse. Particolare attenzione è posta per l’edizione Giunti del 1584, la quale, oltre ad essere l’unica di cui si conosce l’autore delle incisioni, è la prima a presentare illustrazioni a tutta pagina. Si cerca quindi di individuare il motivo per cui sia avvenuto questo passaggio, operando un confronto con testi a stampa che presentano un’evoluzione iconografica analoga e, in secondo luogo, con le immagini devozionali nelle quali trovano applicazione le tecniche di memorizzazione, il cui impiego si riscontra probabilmente anche in tali incisioni. The illustrations in the sixteenth Editions of Ovidio's Metamorphoses, translated by Giovanni Andrea dell'Anguillara, have been never studied in depth. The paper focuses on the analysis of all iconographic series with the aim to make an accurate comparison among them. Particularly, the attention is addressed to the Giunti’s edition in 1584, which is the only one where the engravings’ author is known and the first one where the illustrations are full-page. The purpose is to find the reason of this shift by comparing those illustrations with printed texts that have a similar iconographic evolution and with devotional images characterized by memorization techniques, which have been probably used also for the engravings in the Giunti’s edition.

  6. Fault Diagnosis and Fault Handling for Autonomous Aircraft

    DEFF Research Database (Denmark)

    Hansen, Søren

    Unmanned Aerial vehicles (UAVs) or drones are used increasingly for missions where piloted aircraft are unsuitable. The unmanned aircraft has a number of advantages with respect to size, weight and manoeuvrability that makes it possible for them to solve tasks that an aircraft previously has been...... to another type of aircraft with different parameters. Amongst the main findings of this research project is a method to handle faults on the UAV’s pitot tube, which measures the aircraft speed. A set of software redundancies based on GPS velocity information and engine thrust are used to detect abnormal...

  7. Applying wavelet entropy principle in fault classification

    Energy Technology Data Exchange (ETDEWEB)

    El Safty, S.; El-Zonkoly, A. [Arab Academy for Science and Technology, Miami, Alexandria, P.O.1029 (Egypt)


    The ability to detect and classify the type of fault plays a great role in the protection of power system. This procedure is required to be precise with no time consumption. In this paper detection of fault type has been implemented using wavelet analysis together with wavelet entropy principle. The simulation of power system is carried out using PSCAD/EMTDC. Different types of faults were studied obtaining various current waveforms. These current waveforms were decomposed using wavelet analysis into different approximation and details. The wavelet entropies of such decompositions are analyzed reaching a successful methodology for fault classification. The suggested approach is tested using different fault types and proven successful identification for the type of fault. (author)

  8. Streamflow gains and losses along San Francisquito Creek and characterization of surface-water and ground-water quality, southern San Mateo and northern Santa Clara counties, California, 1996-97 (United States)

    Metzger, Loren F.


    San Francisquito Creek is an important source of recharge to the 22-square-mile San Francisquito Creek alluvial fan ground-water subbasin in the southern San Mateo and northern Santa Clara Counties of California. Ground water supplies as much as 20 percent of the water to some area communities. Local residents are concerned that infiltration and consequently ground-water recharge would be reduced if additional flood-control measures are implemented along San Francisquito Creek. To improve the understanding of the surface-water/ground-water interaction between San Francisquito Creek and the San Francisquito Creek alluvial fan, the U.S. Geological Survey (USGS) estimated streamflow gains and losses along San Francisquito Creek and determined the chemical quality and isotopic composition of surface and ground water in the study area.Streamflow was measured at 13 temporary streamflow-measurement stations to determine streamflow gains and losses along a 8.4-mile section of San Francisquito Creek. A series of five seepage runs between April 1996 and May 1997 indicate that losses in San Francisquito Creek were negligible until it crossed the Pulgas Fault at Sand Hill Road. Streamflow losses increased between Sand Hill Road and Middlefield Road where the alluvial deposits are predominantly coarse-grained and the water table is below the bottom of the channel. The greatest streamflow losses were measured along a 1.8-mile section of the creek between the San Mateo Drive bike bridge and Middlefield Road; average losses between San Mateo Drive and Alma Street and from there to Middlefield Road were 3.1 and 2.5 acre-feet per day, respectively.Downstream from Middlefield Road, streamflow gains and losses owing to seepage may be masked by urban runoff, changes in bank storage, and tidal effects from San Francisco Bay. Streamflow gains measured between Middlefield Road and the 1200 block of Woodland Avenue may be attributable to urban runoff and (or) ground-water inflow. Water

  9. Species - San Diego Co. [ds121 (United States)

    California Department of Resources — This is the Biological Observation Database point layer representing baseline observations of sensitive species (as defined by the MSCP) throughout San Diego County....

  10. Active fault diagnosis in closed-loop systems

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad


    Active fault diagnosis (AFD) of parametric faults is considered in connection with closed loop feedback systems. AFD involves auxiliary signals applied on the closed loop system. A fault signature matrix is introduced in connection with AFD and it is shown that if a limited number of faults can...... occur in the system, a fault separation in the fault signature matrix can be obtained. Then the single elements in the matrix only depend of a reduced number of parametric faults. This can directly be applied for fault isolation. If it is not possible to obtain this separation, it is shown how the fault...... signature matrix can be applied for a dynamical fault isolation, i.e. fault isolation based on the dynamic characteristic of the fault signature matrix as function of the different parametric faults....

  11. An Active Fault-Tolerant Control Method Ofunmanned Underwater Vehicles with Continuous and Uncertain Faults

    Directory of Open Access Journals (Sweden)

    Daqi Zhu


    Full Text Available This paper introduces a novel thruster fault diagnosis and accommodation system for open-frame underwater vehicles with abrupt faults. The proposed system consists of two subsystems: a fault diagnosis subsystem and a fault accommodation sub-system. In the fault diagnosis subsystem a ICMAC(Improved Credit Assignment Cerebellar Model Articulation Controllers neural network is used to realize the on-line fault identification and the weighting matrix computation. The fault accommodation subsystem uses a control algorithm based on weighted pseudo-inverse to find the solution of the contro