Download or read book Seismicity and Structure of the Orozco Transform Fault from Ocean Bottom Seismic Observation Anne Martine Tr hu written by Anne Martine Tréhu and published by . This book was released on 1982* with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seismicity and Structure of the Orozco Transform Fault from Ocean Bottom Seismic Observations written by Anne Martine Tréhu and published by . This book was released on 1982 with total page 371 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seismic waves generated by sources ranging from 2.7 kg shots of TNT to magnitude 5 earthquakes were studied in order to determine the seismic activity and crystal structure of the Orozco transform fault. Most of the data were collected by a network of 29 ocean bottom seismometers (OBS) and hydrophones (OBH) which were deployed as part of a project ROSE (Rivera Ocean Seismic Experiment). Additional information was provided by magnetic anomaly and bathymetric data collected during and prior to ROSE and by teleseismic earthquakes recorded by the WWSSN (Worldwide Seismic Station Network). (Author).
Download or read book Seismicity and Structure of the Orozco Transform Fault from Ocean Bottom Seismic Observations written by and published by . This book was released on 1982 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seismicity and Structure of the Orozco Transform Fault written by Anne Martine Tréhu and published by . This book was released on 1982 with total page 740 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in ocean bottom seismology written by Francisco Javier Nuñez-Cornu and published by Frontiers Media SA. This book was released on 2023-03-27 with total page 199 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Seismogenic Zone of Subduction Thrust Faults written by Timothy H. Dixon and published by Columbia University Press. This book was released on 2007-09-20 with total page 691 pages. Available in PDF, EPUB and Kindle. Book excerpt: Subduction zones, one of the three types of plate boundaries, return Earth's surface to its deep interior. Because subduction zones are gently inclined at shallow depths and depress Earth's temperature gradient, they have the largest seismogenic area of any plate boundary. Consequently, subduction zones generate Earth's largest earthquakes and most destructive tsunamis. As tragically demonstrated by the Sumatra earthquake and tsunami of December 2004, these events often impact densely populated coastal areas and cause large numbers of fatalities. While scientists have a general understanding of the seismogenic zone, many critical details remain obscure. This volume attempts to answer such fundamental concerns as why some interplate subduction earthquakes are relatively modest in rupture length (greater than 100 km) while others, such as the great (M greater than 9) 1960 Chile, 1964 Alaska, and 2004 Sumatra events, rupture along 1000 km or more. Contributors also address why certain subduction zones are fully locked, accumulating elastic strain at essentially the full plate convergence rate, while others appear to be only partially coupled or even freely slipping; whether these locking patterns persist through the seismic cycle; and what is the role of sediments and fluids on the incoming plate. Nineteen papers written by experts in a variety of fields review the most current lab, field, and theoretical research on the origins and mechanics of subduction zone earthquakes and suggest further areas of exploration. They consider the composition of incoming plates, laboratory studies concerning sediment evolution during subduction and fault frictional properties, seismic and geodetic studies, and regional scale deformation. The forces behind subduction zone earthquakes are of increasing environmental and societal importance.
Download or read book Neogene Deformation of the Mt Angel Gales Creek Fault Zone written by Martin E. Dougherty and published by . This book was released on 1997 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seismic Behavior on Oceanic Transform Faults Revealed by Numerical Modeling and Seismic Observation written by Pengcheng Shi and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Summaries of Technical Reports Volume X written by and published by . This book was released on 1980 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Dynamics of Ocean Transform Faults written by Patricia Michelle Marie Gregg and published by . This book was released on 2008 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: Segmentation and crustal accretion at oceanic transform fault systems are investigated through a combination of geophysical data analysis and geodynamical and geochemical modeling. Chapter 1 examines the effect of fault segmentation on the maximum predicted earthquake magnitude of an oceanic transform fault system. Results of thermal modeling suggest that fault segmentation by intra-transform spreading centers (ITSC) drastically reduces the available brittle area of a transform fault and thus limits the available earthquake rupture area. Coulomb stress models suggest that long ITSCs will prohibit static stress interaction between segments of a transform system and further limit the maximum possible magnitude of a given transform fault earthquake. In Chapter 2, gravity anomalies from a global set of oceanic transform fault systems are investigated. Surprisingly, negative residual mantle Bouguer gravity anomalies are found within fastslipping transform fault domains. These gravity observations suggest a mass deficit within fast-slipping transform faults, which may result from porosity variations, mantle serpentinization, and/or crustal thickness variations. Two-dimensional forward modeling and the correlation of the negative gravity anomalies to bathymetric highs indicate crustal thickness excesses in these locations. Finally, in Chapter 3, mantle thermal and melting models for a visco-plastic rheology are developed to investigate the process of mantle melting and crustal accretion at ITSCs within segmented transform faults, and are applied to the Siqueiros transform fault system. Models in which melt migrates into the transform fault domain from a large region of the mantle best explain the gravity-derived crustal thickness variations observed at the Siqueiros transform. Furthermore, a mantle potential temperature of 1350°C and fractional crystallization at depths of 9 - 15.5 km best explain the major element composition variation observed at the Siqueiros transform.
Download or read book Oceanographer Transform Fault Structure Compared to that of Surrounding Oceanic Crust written by E. L. Ambos and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Deep Earthquakes written by Cliff Frohlich and published by Cambridge University Press. This book was released on 2006-05-04 with total page 558 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive, topical, historical, and geographical summary of deep earthquakes and related phenomena.
Download or read book The Isostasy and Crustal Structure of the East Pacific Rise and the Morphotectonic Fabric of the Orozco Transform Fault written by John Alfred Madsen and published by . This book was released on 1988 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Dynamics of Oceanic Transform Faults written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: National Science Foundation Graduate Research Fellowship, Hollister Graduate Research Fellowship, WHOI Academic Programs Office - Research Fellowship.
Download or read book Tectonics of the Oceanographer Transform Seismic Evidence written by Hugh Rowlett and published by . This book was released on 1978 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ocean-bottom seismographs (OBS's) were used in a combined refraction and microearthquake monitoring experiment at the eastern junction of the Oceanographer transform with the mid-Atlantic ridge at 35 N. Microearthquake activity at the junction occurred over a zone at least 7 km wide. Microearthquakes that were located define a linear zone of faulting up to 12 km in length and about 3 km in width that is oblique to both the local strike of the median valley and transform valley and the present direction of spreading. These microearthquakes appear to be associated with fault scarps that form the inner walls on the west and north sides of the median and transform valleys.
Download or read book Crustal Structure and Seismicity of the Gorda Ridge written by Ariel E. Solano-Borrego and published by . This book was released on 1984 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have determined the seismic crustal structure of the northern part of the Gorda Ridge using signals generated by explosive charges and recorded on Ocean Bottom Seismometers. The shot pattern forms two parallel lines, one on the east flank and the other along the median valley. Inversion of the travel time data and synthetic modelling of the signals resulted in two compressional velocity structures: the model for the flank indicates a 1.6 km thick upper crust characterized by high velocity gradients and 3.6 km thick lower crust characterized by a low gradient. A sharp mantle transition exists at 5.2 km depth with an upper mantle velocity of 7.6 km/sec. The median valley velocity model has a thicker high gradient upper crust of 3.0 km and a lower crust of at least 3.5 km thickness. No upper mantle velocities were detected beneath the median valley. We have also monitored the seismicity of the ridge during 15 days with two arrays of OBS and detected ~4 events/hour. Epicentral coordinates were determined for 140 earthquakes. Most of them lie within the median valley and show spatial clustering. Intraplate seismicity was also detected in the Gorda Basin with three of the earthquakes big enough to be reported by land stations. They suggest that the Gorda Plate is presently undergoing deformation. Good control over the focal depth was possible for ~80 earthquakes occurring on the ridge, and there the seismic activity appears to be pervasive throughout the upper 20 km suggesting that the the brittle lithosphere is at least this thick. From the earthquake shear-wave data we have obtained a value of 1.73 for the Vp/Vs ratio. Moments of the well constrained events derived from the spectra of the waveforms are of the order 1020 dyne-cm and suggest an average fault width of 300 m. The refraction data is consistent with the earthquake results, and all the evidence suggests that a large magma chamber underlying the axis of spreading does not presently exist at shallow depths.
Download or read book Living with Earthquakes in the Pacific Northwest written by Robert S. Yeats and published by . This book was released on 1998 with total page 309 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes the serious threat posed by one of the world's great earthquake faults -- the Cascadia Subduction Zone -- which runs for hundreds of miles offshore from British Columbia to northern California.
