[ { "id": "https://authors.library.caltech.edu/records/pyrsh-8pt24", "eprint_id": 44263, "eprint_status": "archive", "datestamp": "2023-08-19 20:46:03", "lastmod": "2023-10-26 00:20:38", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Zoback-M-D", "name": { "family": "Zoback", "given": "Mark D." }, "orcid": "0000-0002-8851-2099" }, { "id": "Silver-L-T", "name": { "family": "Silver", "given": "Leon T." } }, { "id": "Henyey-T-L", "name": { "family": "Henyey", "given": "Thomas" } }, { "id": "Thatcher-W", "name": { "family": "Thatcher", "given": "Wayne" } } ] }, "title": "The Cajon Pass Scientific Drilling Experiment: Overview of phase 1", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1988 American Geophysical Union. Received: May 5, 1988;\nAccepted: June 27, 1988. \n\nWe wish to thank the National Science Foundation for providing financial support through DOSECC, Inc. for the Cajon Pass project and the U.S. Geological Survey for providing on site core-handling facilities and personnel and financial support for USGS scientists involved in the project We owe a considerable debt to Robert Johnson, DOSECC project supervisor, for providing engineering talent and advice for the project as a whole and for many members of the science team. We wish to thank Wayne Campbell, Francis Raup, Deborah Volturno and William Linenburger of the USGS core-handling team for their help. Many of the contractors associated with this project have provided assistance and services far beyond the terms and conditions of their contracts. We wish to thank in particular Steven Pittillo, Mark Andrews and Barney Thompson of Parker\nDrilling Co. and Bill Anderson, Doug Milham and Rick Behl of\nEpoch Mud Logging Services for providing considerable\nassistance to the scientists involved in this project\n\n
Published - grl4042.pdf
", "abstract": "The Cajon Pass Scientific Drilling Project is a broad, interdisciplinary experiment involving over two dozen principal scientists. Phase I of drilling, coring and downhole experimentation began Dec. 8, 1986 and ended April 2, 1987 with the hole at a depth of 2115 m, 82 m of core recovered and a wide range of downhole experiments successfully completed. In this paper we briefly outline the scientific motivation for the project and provide an overview of the scientific program. We also indicate some of the varied research areas in the earth sciences where data obtained in this experiment will provide unique and important insight into active in situ processes, regional geologic structure, and rock and fluid composition and origin.", "date": "1988-08", "date_type": "published", "publication": "Geophysical Research Letters", "volume": "15", "number": "9", "publisher": "American Geophysical Union", "pagerange": "933-936", "id_number": "CaltechAUTHORS:20140311-151633689", "issn": "0094-8276", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140311-151633689", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF" }, { "agency": "USGS" } ] }, "doi": "10.1029/GL015i009p00933", "primary_object": { "basename": "grl4042.pdf", "url": "https://authors.library.caltech.edu/records/pyrsh-8pt24/files/grl4042.pdf" }, "resource_type": "article", "pub_year": "1988", "author_list": "Zoback, Mark D.; Silver, Leon T.; et el." }, { "id": "https://authors.library.caltech.edu/records/xt586-z0c35", "eprint_id": 68967, "eprint_status": "archive", "datestamp": "2023-08-19 09:31:45", "lastmod": "2023-10-20 16:23:02", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Hanks-T-C", "name": { "family": "Hanks", "given": "Thomas C." } }, { "id": "Hileman-J-A", "name": { "family": "Hileman", "given": "James A." } }, { "id": "Thatcher-W", "name": { "family": "Thatcher", "given": "Wayne" } } ] }, "title": "Seismic Moments of the Larger Earthquakes of the Southern California Region", "ispublished": "pub", "full_text_status": "restricted", "note": "\u00a9 1975 Geological Society of America. \n\nManuscript received by the Society July 5, 1975; Revised manuscript received February 18, 1975; Manuscript accepted March 7, 1975. \n\nWe are indebted to the staff of the Seismographic Station of the University of California, Berkeley, especially T. V. McEvilly, for providing access to seismograms of the Berkeley station. We enjoyed\nthe critical remarks of C. R. Allen, R. L. Brown, and J. W. Dewey. This research was supported in part by the Earthquake Research Affiliates of the California Institute of Technology.", "abstract": "The seismic moment (M_0) of an earthquake is a more consistent and more physical measure of source strength than magnitude (M) or strain release (see pdf for formula), and this measure of source strength is determined for 47 of the larger earthquakes occurring in the Southern California region since 1857. Most of the seismic moments are obtained by conventional seismological means, but a relationship between M_0 and the areal distribution of Intensity VI (A_(VI)) is developed and scaled to estimate M_0 when intensity data are available but instrumental data are not. This relationship is log M_0 = 1.97 log A_(VI) \u2212 2.55. For the region as a whole, earthquakes at the threshold of M_0 \u2265 10^(25), \u226510^(26), and \u226510^(27) dyne-cm have occurred once every 3, 8, and 25 yr, respectively. The spatial occurrence of the five largest earthquakes (M_0 \u2265 1 \u00d7 10^(27) dyne-cm) is not limited to a particular geologic province, mode of tectonic accommodation, or geographic locality. It is unlikely that this data set can reliably predict long-term spatial and temporal patterns of the M_0 \u2265 10^(25) dyne-cm seismicity of the Southern California region.", "date": "1975-08", "date_type": "published", "publication": "Geological Society of America Bulletin", "volume": "86", "number": "8", "publisher": "Geological Society of America", "pagerange": "1131-1139", "id_number": "CaltechAUTHORS:20160711-140357524", "issn": "0016-7606", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160711-140357524", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech Earthquake Research Affiliates" } ] }, "doi": "10.1130/0016-7606(1975)86<1131:SMOTLE>2.0.CO;2", "resource_type": "article", "pub_year": "1975", "author_list": "Hanks, Thomas C.; Hileman, James A.; et el." }, { "id": "https://authors.library.caltech.edu/records/qjjt7-yns96", "eprint_id": 98573, "eprint_status": "archive", "datestamp": "2023-08-19 09:32:32", "lastmod": "2023-10-18 17:28:35", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Thatcher-W", "name": { "family": "Thatcher", "given": "Wayne" } }, { "id": "Hileman-J-A", "name": { "family": "Hileman", "given": "James A." } }, { "id": "Hanks-T-C", "name": { "family": "Hanks", "given": "Thomas C." } } ] }, "title": "Seismic Slip Distribution along the San Jacinto Fault Zone, Southern California, and Its Implications", "ispublished": "pub", "full_text_status": "restricted", "keywords": "seismology, earthquake moment, seismic slip, seismic gaps, earthquake prediction", "note": "\u00a9 1975 Geological Society of America. \n\nManuscript received by the Society July 4, 1974; Revised manuscript received February 18, 1975; Manuscript accepted March 7, 1975. \n\nDoc. no. 50814. \n\nThe staff of the Seismographic Station of the University of California at Berkeley, particularly T. V. McEvilly, are thanked for their assistance in providing access to the seismographic records from the Berkeley station. R. V. Sharp, D. P. Hill, and J. C. Savage provided helpful discussion. M. M. Clark's careful review considerably improved the manuscript.", "abstract": "The amount and distribution of seismic slip along 240 km of the San Jacinto fault zone between Cajon Pass and Superstition Mountain has been obtained from determinations of seismic moment and estimates of source dimension for each of the nine moderate earthquakes (6 < M < 7) which have occurred there since 1890.\n\nThere are two significant gaps in seismic slip, one between Cajon Pass and Riverside, the other from Anza to Coyote Mountain. Each is about 40 km long and both are characterized by complex fault zones and a currently high level of minor seismicity (M < 5). No aseismic fault creep has been identified on either segment. These gaps may mark the sites of the next moderate earthquakes (M = 6 \u2192 7) to occur along the San Jacinto fault zone. The two remaining sections of the fault, Riverside and Anza, and Coyote Mountain to Superstition Mountain, may have been ruptured along their entire lengths, in 1890\u20131923 and 1942\u20131968, respectively.", "date": "1975-08", "date_type": "published", "publication": "Geological Society of America Bulletin", "volume": "86", "number": "8", "publisher": "Geological Society of America", "pagerange": "1140-1146", "id_number": "CaltechAUTHORS:20190911-095913842", "issn": "0016-7606", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190911-095913842", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "Seismological-Laboratory" } ] }, "doi": "10.1130/0016-7606(1975)86%3C1140:SSDATS%3E2.0.CO;2", "resource_type": "article", "pub_year": "1975", "author_list": "Thatcher, Wayne; Hileman, James A.; et el." }, { "id": "https://authors.library.caltech.edu/records/6dchg-asj27", "eprint_id": 51916, "eprint_status": "archive", "datestamp": "2023-08-19 07:28:35", "lastmod": "2023-10-18 18:41:52", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Thatcher-W", "name": { "family": "Thatcher", "given": "Wayne" } }, { "id": "Brune-J-N", "name": { "family": "Brune", "given": "James N." } } ] }, "title": "Seismic Study of an Oceanic Ridge Earthquake Swarm in the Gulf of California", "ispublished": "pub", "full_text_status": "public", "note": "Copyright \u00a9 1971 The Royal Astronomical Society. \n\nIn original form 1970 October 6. Received 1970 December 29. \n\nThe research reported in this paper was made possible through a cooperative research program with the National University of Mexico initiated in January 1969. The aid and cooperation of the National University of Mexico (UNAM) and the Comission Federale de Electricidad (CFE) in carrying out field investigations is gratefully acknowledged. In particular, Dr Cinna Lomnitz of UNAM provided crucial aid and support in the installation of the Rio Hardy station. This station was attended and serviced by CFE personnel and the records were processed and read at UNAM. \n\nlnformal discussions with Dr L. R. Sykes, P. Molnar, and D. P. Hill were helpful. Dr Sykes kindly furnished a preprint of his paper in advance of publication. Dr C. R. Allen, Mr T. C. Hanks, and Dr Cinna Lomnitz read the manuscript and made helpful suggestions. \n\nOne of the portable seismographs used in this study was purchased from funds associated with the Grove Karl Gilbert Award in Seismic Geology (H. O. Wood Fund) awarded to one of us (J.N.B.). \n\nThe research was supported by NSF grants GA 11133 and GA 12868.\n\nPublished - Geophys._J._Int.-1971-Thatcher-473-89.pdf
", "abstract": "Detailed seismic investigation of an unusually intense earthquake swarm which occurred in the northern Gulf of California during March 1969 has provided new information about seismic processes which occur on actively spreading oceanic ridges and has placed some constraints on the elastic wave velocities beneath them. Activity during this swarm was similar to that of a foreshock-mainshock-aftershock sequence, but with a 'mainshock' composed of over 70 events with magnitudes between 4 and 5.5 occurring in a 6-hr period about a day after swarm activity was initiated. 'Aftershocks', including many events greater than magnitude 5, continued for over two weeks. Near-source travel-time data indicate all sources located are within 5\u201310 km of each other and that hypocentres are confined to the upper crust. Teleseismic P-delays for rays travelling beneath this ridge may be interpreted in terms of an upper mantle with compressional velocities 5\u201310 per cent less than normal mantle to a depth of 200 km. Average apparent stresses for all swarm events studied are very similar, show no consistent pattern as a function of time, and are close to values obtained from other ridges. The focal mechanism solution shows a large component of normal faulting. An apparent non-orthogonality of nodal planes common to this mechanism solution and to normal faulting events on other ridges disappears when the indicated low upper mantle velocities beneath the source are taken into account. \n\nA survey of recent seismicity (post 1962) in the northern Gulf suggests seismic coupling across about 200 km between adjacent inferred spreading ridge segments. \n\nSurface waves from these Gulf Swarm earthquakes have amplitudes from one to two orders of magnitude greater than Northern Baja California events with similar short period body wave excitation.", "date": "1971-05", "date_type": "published", "publication": "Geophysical Journal of the Royal Astronomical Society", "volume": "22", "number": "5", "publisher": "Royal Astronomical Society", "pagerange": "473-489", "id_number": "CaltechAUTHORS:20141118-135845716", "issn": "0016-8009", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141118-135845716", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Grove Karl Gilbert Award in Seismic Geology" }, { "agency": "NSF", "grant_number": "GA 11133" }, { "agency": "NSF", "grant_number": "GA 12868" } ] }, "doi": "10.1111/j.1365-246X.1971.tb03615.x", "primary_object": { "basename": "Geophys._J._Int.-1971-Thatcher-473-89.pdf", "url": "https://authors.library.caltech.edu/records/6dchg-asj27/files/Geophys._J._Int.-1971-Thatcher-473-89.pdf" }, "resource_type": "article", "pub_year": "1971", "author_list": "Thatcher, Wayne and Brune, James N." }, { "id": "https://authors.library.caltech.edu/records/wz2xg-99x69", "eprint_id": 48443, "eprint_status": "archive", "datestamp": "2023-08-19 07:26:52", "lastmod": "2023-10-17 19:21:23", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Abrams-M", "name": { "family": "Abrams", "given": "M." } }, { "id": "Allen-C-R", "name": { "family": "Allen", "given": "C." } }, { "id": "Anderson-D-L", "name": { "family": "Anderson", "given": "D." } }, { "id": "Berkey-N", "name": { "family": "Berkey", "given": "N." } }, { "id": "Carey-D", "name": { "family": "Carey", "given": "D." } }, { "id": "Carter-B", "name": { "family": "Carter", "given": "B." } }, { "id": "Davies-G", "name": { "family": "Davies", "given": "G." } }, { "id": "Engen-G-R", "name": { "family": "Engen", "given": "G." } }, { "id": "Foley-M-G", "name": { "family": "Foley", "given": "M." } }, { "id": "Hanks-T-C", "name": { "family": "Hanks", "given": "T." } }, { "id": "Helmberger-D-V", "name": { "family": "Helmberger", "given": "D." } }, { "id": "Hileman-J-A", "name": { "family": "Hileman", "given": "J." } }, { "id": "Jordan-T", "name": { "family": "Jordan", "given": "T." } }, { "id": "Jungels-P", "name": { "family": "Jungels", "given": "P." } }, { "id": "Kamb-B", "name": { "family": "Kamb", "given": "B." } }, { "id": "Liu-H", "name": { "family": "Liu", "given": "H." } }, { "id": "Minster-B", "name": { "family": "Minster", "given": "B." } }, { "id": "Nordquist-J-M", "name": { "family": "Nordquist", "given": "J." } }, { "id": "Penrose-B", "name": { "family": "Penrose", "given": "B." } }, { "id": "Silver-L-T", "name": { "family": "Silver", "given": "L." } }, { "id": "Smith-R", "name": { "family": "Smith", "given": "R." } }, { "id": "Thatcher-W", "name": { "family": "Thatcher", "given": "W." } }, { "id": "Thomsen-L", "name": { "family": "Thomsen", "given": "L." } }, { "id": "Whitcomb-J-H", "name": { "family": "Whitcomb", "given": "J." } }, { "id": "Wood-S", "name": { "family": "Wood", "given": "S." } } ] }, "title": "Preliminary seismological and geological studies of the San Fernando, California, earthquake of February 9 1971", "ispublished": "pub", "full_text_status": "public", "note": "Copyright \u00a9 1971, by the Seismological Society of America.\n\nMany aspects of this study have been made possible by contributions over the years by the\nCaltech Earthquake Research Affiliates, a group of private sponsors whose help is particularly\nappreciated at times such as this. Postearthquake aerial photographic coverage was kindly supplied\nby the U.S. Geological Survey and Woodward, Lundgren and Associates. We also appreciate\nthe generosity and the spirit of free communication that has typified all the groups and individuals\ninvestigating this earthquake.\n\nPublished - 491.full.pdf
", "abstract": "The San Fernando earthquake was the largest earthquake to occur in the metropolitan Los\nAngeles area in more than 50 years. It has tentatively been assigned a magnitude, M_L of 6.6, a focal\ndepth of 13.0 km, and an epicentral location about 12 km east of Newhall, California, at 34\u00b024.0'N,\n118\u00b023.7'W (Figure 1), but these figures undoubtedly will be modified as further data become available.\nAlthough the focal depth is not as well defined as the epicenter, it is consistent with other\nobservations suggesting thrusting on a fault plane dipping north about 45 \u00b0 and breaking the surface\nin the Sylmar-San Fernando area (Figure 1). It should be emphasized that the hypocenter of\nthe main shock represents only the point of initial rupture. Breaking, presumably, then propagated\nsouthward and upward from this point, so that the main geological and engineering effects\nwere observed farther south where the fault was shallower and the displacement greater. The location\nof the main shock is based on readings from permanent stations of the Caltech network, as\nwell as the U. S. Geological Survey station at Point Mugu (SBLG) and the California Department\nof Water Resources stations at Pyramid (PYR) and Cedar Springs (CSP). Portable Caltech seismographs\nwere installed in the epicentral area as early as 3 hr following the main shock, and,\nwithin a few days, there were at least 30 portable units in the region operated by various groups\nand agencies.", "date": "1971-04", "date_type": "published", "publication": "Bulletin of the Seismological Society of America", "volume": "61", "number": "2", "publisher": "Seismological Society of America", "pagerange": "491-495", "id_number": "CaltechAUTHORS:20140812-151015768", "issn": "0037-1106", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140812-151015768", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "Caltech Earthquake Research Affiliates" } ] }, "other_numbering_system": { "items": [ { "id": "1986", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "corp_creators": { "items": [ "Caltech Division of Geological and Planetary Sciences" ] }, "primary_object": { "basename": "491.full.pdf", "url": "https://authors.library.caltech.edu/records/wz2xg-99x69/files/491.full.pdf" }, "resource_type": "article", "pub_year": "1971", "author_list": "Abrams, M.; Allen, C.; et el." }, { "id": "https://authors.library.caltech.edu/records/69yd0-pxq15", "eprint_id": 49978, "eprint_status": "archive", "datestamp": "2023-08-19 07:05:19", "lastmod": "2023-10-17 22:25:04", "type": "article", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lomnitz-C", "name": { "family": "Lomnitz", "given": "Cinna" } }, { "id": "Mooser-F", "name": { "family": "Mooser", "given": "Federico" } }, { "id": "Allen-C-R", "name": { "family": "Allen", "given": "Clarence R." } }, { "id": "Brune-J-N", "name": { "family": "Brune", "given": "James N." } }, { "id": "Thatcher-W", "name": { "family": "Thatcher", "given": "Wayne" } } ] }, "title": "Seismicity and Tectonics of the Northern Gulf of California Region, Mexico. Preliminary Results", "ispublished": "pub", "full_text_status": "public", "note": "\u00a9 1970 Instituto de Geofisica de la Universidad Nacional Autonoma de Mexico. \n\nContribuci\u03ccn conjunta de'la Universidad Nacional Aut\u03ccnoma\nde Mexico (U.N.A.M.) (Instituto de Geofisica, Contribuci\u03ccn. No, 1042), el lnstituto Tecnol\u03ccgico de California (Division de Ciencias Geol\u03ccgicas, Contribuci\u03ccn No. 1948) y la Universidad de California, San Diego (Instituto de Geofisica y Fisica Planetaria, Contribuci\u03ccn No....\n\nThis work has, been supported in part by U.S. National\nScience Foundation grants GA-715 (Heat Flow), GA-12868 (Earthquake Mechanisms) and GA-21397 (Gulf of California Seismographic Network). The assistance of the C.F.E. in Mexicali (Ing. V. Martinez Martel, Chief) was of great importance in establishing and operating the seismographic stations.\n\nPublished - Allen_1970p37.pdf
", "abstract": "Three new seismographic statioms have been established\u00b7 in the\nnorthern Gulf of California region; Mexico. Seismicity ,during a\nrepresentative period in April and May of 1969 was concentrated\non the Imperial, San Jacinto, Sierra Juarez, .and San Miguel\nfaults, and the spread of epicentral locations was m\\!Ch less than\nhad previously been indicated. An intense earthquake swarm in\nMarch of\u00b7 1969 occurred near Consag Rock in the northern Gulf,\nand its study contributes to our understanding of the regional\ntectonics. In the northern Gulf of California and adjacent Salton\ntrough, the tectonic framework may be. approximated by a series\nof six transform faults connected by five spreading centers (ridge,\nsegments) evidenced by geothermal areas, recent .. volcanic activity,\nearthquake swarms, and submarine topographic depressions. Complexities\nin the fault pattern may be related to a northward decrease\nin spreading rates along the ridge segment,s. Five new high;\nquality seismographic stations around the \u2022Gulf of California are\nnow under construction in order to understand in more detail the\npattern of sea-floor spreading in this unique, and important region.", "date": "1970-04-01", "date_type": "published", "publication": "Geofisica Internacional", "volume": "10", "number": "2", "publisher": "Union Fisica Mexicana", "pagerange": "37-48", "id_number": "CaltechAUTHORS:20140924-091244669", "issn": "0016-7169", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140924-091244669", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "funders": { "items": [ { "agency": "NSF", "grant_number": "GA-715" }, { "agency": "NSF", "grant_number": "GA-12868" }, { "agency": "NSF", "grant_number": "GA-21397" } ] }, "other_numbering_system": { "items": [ { "id": "1948", "name": "Caltech Division of Geological and Planetary Sciences" } ] }, "primary_object": { "basename": "Allen_1970p37.pdf", "url": "https://authors.library.caltech.edu/records/69yd0-pxq15/files/Allen_1970p37.pdf" }, "resource_type": "article", "pub_year": "1970", "author_list": "Lomnitz, Cinna; Mooser, Federico; et el." } ]