Structure and Mechanics of the Subducted Gorda Plate
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Washington Division of Geology and Earth Resources Open File Report
l 122 EARTHQUAKES AND SEISMOLOGY - LEGAL ASPECTS OPEN FILE REPORT 92-2 EARTHQUAKES AND Ludwin, R. S.; Malone, S. D.; Crosson, R. EARTHQUAKES AND SEISMOLOGY - LEGAL S.; Qamar, A. I., 1991, Washington SEISMOLOGY - 1946 EVENT ASPECTS eanhquak:es, 1985. Clague, J. J., 1989, Research on eanh- Ludwin, R. S.; Qamar, A. I., 1991, Reeval Perkins, J. B.; Moy, Kenneth, 1989, Llabil quak:e-induced ground failures in south uation of the 19th century Washington ity of local government for earthquake western British Columbia [abstract). and Oregon eanhquake catalog using hazards and losses-A guide to the law Evans, S. G., 1989, The 1946 Mount Colo original accounts-The moderate sized and its impacts in the States of Califor nel Foster rock avalanches and auoci earthquake of May l, 1882 [abstract). nia, Alaska, Utah, and Washington; ated displacement wave, Vancouver Is Final repon. Maley, Richard, 1986, Strong motion accel land, British Columbia. erograph stations in Oregon and Wash Hasegawa, H. S.; Rogers, G. C., 1978, EARTHQUAKES AND ington (April 1986). Appendix C Quantification of the magnitude 7.3, SEISMOLOGY - NETWORKS Malone, S. D., 1991, The HAWK seismic British Columbia earthquake of June 23, AND CATALOGS data acquisition and analysis system 1946. [abstract). Berg, J. W., Jr.; Baker, C. D., 1963, Oregon Hodgson, E. A., 1946, British Columbia eanhquak:es, 1841 through 1958 [ab Milne, W. G., 1953, Seismological investi earthquake, June 23, 1946. gations in British Columbia (abstract). stract). Hodgson, J. H.; Milne, W. G., 1951, Direc Chan, W.W., 1988, Network and array anal Munro, P. S.; Halliday, R. J.; Shannon, W. -
Cambridge University Press 978-1-108-44568-9 — Active Faults of the World Robert Yeats Index More Information
Cambridge University Press 978-1-108-44568-9 — Active Faults of the World Robert Yeats Index More Information Index Abancay Deflection, 201, 204–206, 223 Allmendinger, R. W., 206 Abant, Turkey, earthquake of 1957 Ms 7.0, 286 allochthonous terranes, 26 Abdrakhmatov, K. Y., 381, 383 Alpine fault, New Zealand, 482, 486, 489–490, 493 Abercrombie, R. E., 461, 464 Alps, 245, 249 Abers, G. A., 475–477 Alquist-Priolo Act, California, 75 Abidin, H. Z., 464 Altay Range, 384–387 Abiz, Iran, fault, 318 Alteriis, G., 251 Acambay graben, Mexico, 182 Altiplano Plateau, 190, 191, 200, 204, 205, 222 Acambay, Mexico, earthquake of 1912 Ms 6.7, 181 Altunel, E., 305, 322 Accra, Ghana, earthquake of 1939 M 6.4, 235 Altyn Tagh fault, 336, 355, 358, 360, 362, 364–366, accreted terrane, 3 378 Acocella, V., 234 Alvarado, P., 210, 214 active fault front, 408 Álvarez-Marrón, J. M., 219 Adamek, S., 170 Amaziahu, Dead Sea, fault, 297 Adams, J., 52, 66, 71–73, 87, 494 Ambraseys, N. N., 226, 229–231, 234, 259, 264, 275, Adria, 249, 250 277, 286, 288–290, 292, 296, 300, 301, 311, 321, Afar Triangle and triple junction, 226, 227, 231–233, 328, 334, 339, 341, 352, 353 237 Ammon, C. J., 464 Afghan (Helmand) block, 318 Amuri, New Zealand, earthquake of 1888 Mw 7–7.3, 486 Agadir, Morocco, earthquake of 1960 Ms 5.9, 243 Amurian Plate, 389, 399 Age of Enlightenment, 239 Anatolia Plate, 263, 268, 292, 293 Agua Blanca fault, Baja California, 107 Ancash, Peru, earthquake of 1946 M 6.3 to 6.9, 201 Aguilera, J., vii, 79, 138, 189 Ancón fault, Venezuela, 166 Airy, G. -
Low-Frequency Tremor and Slow Slip Around the Probable Source Region
Proceeding of the UJNR 5th Earthquake Research Panel Meeting, 2004 1 Low-frequency tremor and slow slip around the probable source region of the Tokai Earthquake { A new indicator for the Tokai Earthquake prediction provided by unified seismic networks in Japan { Noriko Kamaya (Seismological and Volcanological Department, JMA), Akio Katsumata (Meteorological College, JMA) and Yuzo Ishigaki ( Seismological and Volcanological Department, JMA) Abstract Enhancement of seismic networks in the Japan Islands of these years revealed occurrence of deep low-frequency continuous tremors of a belt distribution in the southwest Japan, where the subducting Philippine Sea plate reaches depths of 25{40 km. The source region of the tremor is assumed to correspond to boundary region between oceanic and island crusts close to mantle wedge. The east end of the belt tremor distribution is adjacent to the probable source region of the Tokai Earthquake. A slow-slip event has continued in the west of the source region of the Tokai Earthquake since 2000. Synchronous activation of the tremor and slow-slip speed was observed in 2003. This suggests some relationship between the slow-slip and the tremor activity. We expect that the tremor activity could be a new valuable indicator for the Tokai Earthquake prediction. The long duration of the tremor indicates existence of fluid relating to its generation. The most probable fluid is considered to be water produced by dehydration of chlorite and formation of clinopyroxene in the oceanic crust on the basis of data from high pressure and temperature experiments. The northern border of the belt distribution is possibly rimmed by the edge of the mantle wedge because serpentine formation absorbs fluid water. -
This Report Is Preliminary and Has Not Bee Reviewed for Conformity with US
UNITED STATES DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY Northeast-trending subcrustal fault transects western Washington by Kenneth F. Fox, Jr.* Open-File Report 83-398 This report is preliminary and has not bee reviewed for conformity with U.S Geological Survey editorial standards and stratigraphic nomenclature. *U.S. Geological Survey 3^5 Middlefield Road Menlo Park, California 9^025 Page Table of Contents Tectonic setting......................................................... 1 Seisraicity............................................................... 4 Discussion............................................................... 4 References cited......................................................... 6 Figures Figure 1. Magnetic anomalies in the northeastern Pacific................ 8 Figure 2. Bathymetry at intersection of Columbia lineament and Blanco fracture zone................................................. 9 Figure 3. Plane vector representation of movement of Gorda plate........ 10 Figure 4. Reconstruction of Pacific-Juan de Fuca plate geometry 2 m.y. before present................................................ 11 Figure 5. Epicenters of historical earthquakes with intensity greater than V........................................................ 12 TECTONIC SETTING The north-trending magnetic anomalies of the Juan de Fuca plate are off set along two conspicuous northeast-trending lineaments (fig. 1), named the Columbia offset and the Destruction offset by Carlson (1981). The northeast ward projections of these lineaments intersect the continental area of western Washington, hence are of potential significance to the tectonics of the Pacific Northwest region. Pavoni (1966) suggested that these lineaments were left-lateral faults, and that the Columbia, 280 km in length, had 52 km of offset, and the Destruction, with a length of 370 km, had 75 km of offset. Based on Vine's (1968) correlation of the magnetic anomalies mapped in this area by Raff and Mason (1961), with the magnetic reversal time scale, Silver (1971b, p. -
Constraints on the Moho in Japan and Kamchatka
Tectonophysics 609 (2013) 184–201 Contents lists available at ScienceDirect Tectonophysics journal homepage: www.elsevier.com/locate/tecto Review Article Constraints on the Moho in Japan and Kamchatka Takaya Iwasaki a, Vadim Levin b,⁎, Alex Nikulin b, Takashi Iidaka a a Earthquake Research Institute, University of Tokyo, Japan b Rutgers University, NJ, USA article info abstract Article history: This review collects and systematizes in one place a variety of results which offer constraints on the depth Received 1 July 2012 and the nature of the Moho beneath the Kamchatka peninsula and the islands of Japan. We also include stud- Received in revised form 12 November 2012 ies of the Izu–Bonin volcanic arc. All results have already been published separately in a variety of venues, and Accepted 22 November 2012 the primary goal of the present review is to describe them in the same language and in comparable terms. Available online 3 December 2012 For both regions we include studies using artificial and natural seismic sources, such as refraction and reflec- tion profiling, detection and interpretation of converted-mode body waves (receiver functions), surface wave Keywords: Kamchatka dispersion studies (in Kamchatka) and tomographic imaging (in Japan). The amount of work done in Japan is Japan significantly larger than in Kamchatka, and resulting constraints on the properties of the crust and the upper- Crustal structure most mantle are more detailed. Upper-mantle structure Japan and Kamchatka display a number of similarities in their crustal structure, most notably the average Moho crustal thickness in excess of 30 km (typical of continental regions), and the generally gradational nature of the crust–mantle transition where volcanic arcs are presently active. -
ITM International Tectonics Meeting
NUMO-TR-16-04 TOPAZ Project Long-term Tectonic Hazard to Geological Repositories Toward practical application of the ITM-TOPAZ methodology February 2017 Nuclear Waste Management Organization of Japan (NUMO) 2017 年 2 月 初版発行 本資料の全部または一部を複写・複製・転載する場合は,下記へ お問い合わせください。 〒108-0014 東京都港区芝 4 丁目 1 番地 23 号 三田 NN ビル 2 階 原子力発電環境整備機構 技術部 電話 03-6371-4004(技術部) FAX 03-6371-4102 Inquiries about copyright and reproduction should be addressed to: Science and Technology Department Nuclear Waste Management Organization of Japan Mita NN Bldg. 1-23, Shiba 4-chome, Minato-ku, Tokyo 108-0014 Japan ©原子力発電環境整備機構 (Nuclear Waste Management Organization of Japan) 2017 NUMO-TR-16-04 TOPAZ Project Long-term Tectonic Hazard to Geological Repositories Toward practical application of the ITM-TOPAZ methodology February 2017 Nuclear Waste Management Organization of Japan (NUMO) 各章の和文要約 1 序論 本報告書は,国際プロジェクトメンバーが作成した原稿を NUMO が編集したもの である。NUMO は,地層処分システムに著しい影響を及ぼす火山活動や断層活動な どの自然現象の発生可能性を確率論的に評価するための手法として,ITM 手法1を開 発した。続いて,プレート運動の安定性を必ずしも前提にできない超長期の評価に 向けて,ITM-TOPAZ 手法2の開発を進めた。東北地方および中国地方を対象とした ケーススタディを通じて,ITM-TOPAZ 手法の日本の地質環境への基本的な適用性を 確認してきた。今回,ITM-TOPAZ 手法の適用性のさらなる向上を目指し,再び東北 地方を対象に,火山活動・断層活動に加えて隆起・侵食の変遷に関するシナリオの 拡充,それらの影響の評価方法の高度化などを行った。 2 広域変遷シナリオ(RES: Regional Evolution Senarios)の拡充 これまでに例示した将来 100 万年までのプレート運動の変遷に関する四つのシナ リオ(RES1: 現在の傾向が継続,RES2: プレート収束速度が増加,RES3: プレート運 動の方向が変化,RES4: プレート収束速度が減少)における,東北地方の背弧域 (日本海側),脊梁山地,前弧域(太平洋側)での広域的な火山活動,断層活動, 隆起・侵食の傾向について,追加情報に基づき記述を補強した。さらに,最近の科 学的知見の進展を踏まえたシナリオの拡充の可能性について述べた。 3 サイト変遷シナリオ(SES: Site Evolution Senarios)の設定 背弧域(日本海側),脊梁山地,前弧域(太平洋側)を代表する数十 -
California North Coast Offshore Wind Studies
California North Coast Offshore Wind Studies Overview of Geological Hazards This report was prepared by Mark A. Hemphill-Haley, Eileen Hemphill-Haley, and Wyeth Wunderlich of the Humboldt State University Department of Geology. It is part of the California North Coast Offshore Wind Studies collection, edited by Mark Severy, Zachary Alva, Gregory Chapman, Maia Cheli, Tanya Garcia, Christina Ortega, Nicole Salas, Amin Younes, James Zoellick, & Arne Jacobson, and published by the Schatz Energy Research Center in September 2020. The series is available online at schatzcenter.org/wind/ Schatz Energy Research Center Humboldt State University Arcata, CA 95521 | (707) 826-4345 California North Coast Offshore Wind Studies Disclaimer This study was prepared under contract with Humboldt State University Sponsored Programs Foundation with financial support from the Department of Defense, Office of Economic Adjustment. The content reflects the views of the Humboldt State University Sponsored Programs Foundation and does not necessarily reflect the views of the Department of Defense, Office of Economic Adjustment. This report was created under Grant Agreement Number: OPR19100 About the Schatz Energy Research Center The Schatz Energy Research Center at Humboldt State University advances clean and renewable energy. Our projects aim to reduce climate change and pollution while increasing energy access and resilience. Our work is collaborative and multidisciplinary, and we are grateful to the many partners who together make our efforts possible. Learn more about our work at schatzcenter.org Rights and Permissions The material in this work is subject to copyright. Please cite as follows: Hemphill-Haley, M.A., Hemphill-Haley, E. and Wunderlich, W. (2020). -
Evolution History of Gassan Volcano, Northeast Japan Arc
Open Journal of Geology, 2018, 8, 647-661 http://www.scirp.org/journal/ojg ISSN Online: 2161-7589 ISSN Print: 2161-7570 Evolution History of Gassan Volcano, Northeast Japan Arc Ryo Oizumi1, Masao Ban2*, Naoyoshi Iwata2 1Graduate School of Science and Technology, Yamagata University, Yamagata, Japan 2Faculty of Science, Yamagata University, Yamagata, Japan How to cite this paper: Oizumi, R., Ban, Abstract M. and Iwata, N. (2018) Evolution History of Gassan Volcano, Northeast Japan Arc. Evolution history of the volcano is essential not only to characterize the vol- Open Journal of Geology, 8, 647-661. cano, but also consider magma genesis beneath the volcano. Most of the stra- https://doi.org/10.4236/ojg.2018.87038 tovolcanoes in northeast Japan follow a general evolutional course: cone building, horse-shoe shaped caldera forming collapse, and post-caldera stages. Received: June 4, 2018 However, the detailed history of each stage is not well investigated. We inves- Accepted: July 10, 2018 Published: July 13, 2018 tigated evolution history of young edifice of Gassan volcano, representative stratovolcano in rear side of northeast Japan arc. Most of the products are la- Copyright © 2018 by authors and vas, which are divided into two groups by geomorphologic and geologic fea- Scientific Research Publishing Inc. tures. The former (Gassan lower lavas) is composed of relatively thin and This work is licensed under the Creative Commons Attribution-NonCommercial fluidal lavas, whose original geomorphology remains a little, while the latter International License (CC BY-NC 4.0). (Gassan upper lavas) is composed of relatively thick and viscous lavas, whose http://creativecommons.org/licenses/by-nc/4.0/ original geomorphology is moderately preserved. -
Detailed Structures of the Subducted Philippine Sea Plate Beneath
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 104, NO. B1, PAGES 1015-1033,JANUARY 10, 1999 Detailed structuresof the subductedPhilippine Sea plate beneath northeast Taiwan' A new type of double seismiczone Honn Kao and Ruey-JuinRau Instituteof Earth Sciences,Academia Sinica, Taipei, Taiwan Abstract. We studiedthe detailedstructure of the subductedPhilippine Sea plate beneath northeastTaiwan whereoblique subduction, regional collision, and back arc openingare all activelyoccurring. Simultaneousinversion for velocitystructure and earthquakehypocenters areperformed using the vast,high-quality data recorded by the TaiwanSeismic Network. We furthersupplement the inversionresults with earthquakesource parameters determined from inversionof teleseismicP and $H waveforms,a criticalstep to definethe positionof plateinterface and the stateof strainwithin the subductedslab. The mostinteresting feature is that relocatedhypocenters tend to occuralong a two-layeredstructure. The upperlayer is locatedimmediately below the plate interfaceand extendsdown to 70-80 krn at a dip of 40ø- 50ø. Below approximately100 km, the dip increasesdramatically to 700-80ø. The lower layer commencesat 45-50 km andstays approximately parallel to the upperlayer with a separationof 15+5 km in betweendown to 70-80 km. Below thatthe separationdecreases andthe two layersseem to graduallymerge into one Wadati-BenioffZone. We proposeto term the classicdouble seismic zones observed beneath Japan and Kuril as "type I" andthat we observedas "typeII," respectively.A globalsurvey indicates that type II doubleseismic zonesare alsoobserved in New Zealandnear the southernmostNorth Island,Cascadia, just northof the Mendocinotriple junction, and the Cook Inlet areaof Alaska. All of them are locatednear the terrniniof subductedslabs in a tectonicsetting of obliquesubduction. We interpretthe seismogenesisof type II doubleseismic zones as reflecting the lateralcompres- sivestress between the subductedplate and the adjacentlithosphere (originming from oblique subduction)and the downdipextension (from slabpulling force). -
On the Dynamics of the Juan De Fuca Plate
Earth and Planetary Science Letters 189 (2001) 115^131 www.elsevier.com/locate/epsl On the dynamics of the Juan de Fuca plate Rob Govers *, Paul Th. Meijer Faculty of Earth Sciences, Utrecht University, P.O. Box 80.021, 3508 TA Utrecht, The Netherlands Received 11 October 2000; received in revised form 17 April 2001; accepted 27 April 2001 Abstract The Juan de Fuca plate is currently fragmenting along the Nootka fault zone in the north, while the Gorda region in the south shows no evidence of fragmentation. This difference is surprising, as both the northern and southern regions are young relative to the central Juan de Fuca plate. We develop stress models for the Juan de Fuca plate to understand this pattern of breakup. Another objective of our study follows from our hypothesis that small plates are partially driven by larger neighbor plates. The transform push force has been proposed to be such a dynamic interaction between the small Juan de Fuca plate and the Pacific plate. We aim to establish the relative importance of transform push for Juan de Fuca dynamics. Balancing torques from plate tectonic forces like slab pull, ridge push and various resistive forces, we first derive two groups of force models: models which require transform push across the Mendocino Transform fault and models which do not. Intraplate stress orientations computed on the basis of the force models are all close to identical. Orientations of predicted stresses are in agreement with observations. Stress magnitudes are sensitive to the force model we use, but as we have no stress magnitude observations we have no means of discriminating between force models. -
Workshop Reports on Bend-Fault Serpentinization (BFS) and Bend-Fault Hydrology in Old Incoming Plate (H-ODIN)
Workshop reports on Bend-fault serpentinization (BFS) and Bend-Fault Hydrology in Old Incoming Plate (H-ODIN) 19-21 June, 2016, University of London, Royal Halloway Jason P. Morgan, Royal Holloway, University of London, UK Gou Fujie, JAMSTEC, Japan Ingo Grevemeyer, GEOMAR, Germany Tim Henstock, University of Southampton, UK Tomoaki Morishita – Kanazawa University, Japan Damon Teagle, University of Southampton, UK 1. Introduction and workshop goals Crustal hydration at mid-ocean ridges by hydrothermal circulation has been considered to be the first-order control on the degree of the oceanic plate hydration (see ‘Primary Hydration’ region on Fig. 1). Previous ocean drilling projects have aimed to reveal hydration processes and their extent of oceanic crust at spreading centers (e.g., Alt et al., 1996; Bach et al., 2003; Wilson et al., 2006). Recently, hydration due to plate bending-induced normal faults (bend-faults) in the region between the trench axis and outer rise (outer rise hereafter) has also drawn considerable attention (see ‘Rehydration’ region on Fig. 1). During the last decade, multiple independent geophysical structure studies have revealed that plate bending-induced normal faults in outer rise regions around the world are associated with significant hydration along (e.g., Grevemeyer et al., 2007; Ivandic et al., 2008; Key et al., 2012; Fujie et al., 2013). This bend-fault-linked hydration and Bend-Fault Serpentinization (BFS), with its associated physical and chemical changes is one of the most significant geological discoveries of the last 15 years. It has the potential to reshape our understanding of Earth’s deep water and carbon cycles, the ecology and evolution of species in deep-sea chemosynthetic environments, and even the fundamental mechanism by which slabs bend and unbend, thereby driving Plate Tectonics. -
Threedimensional Seismic Velocity Structure and Configuration of The
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 113, B09315, doi:10.1029/2007JB005274, 2008 Three-dimensional seismic velocity structure and configuration of the Philippine Sea slab in southwestern Japan estimated by double-difference tomography Fuyuki Hirose,1 Junichi Nakajima,2 and Akira Hasegawa2 Received 18 July 2007; revised 23 June 2008; accepted 17 July 2008; published 26 September 2008. [1] Three-dimensional seismic velocity structure in and around the Philippine Sea plate subducting beneath southwestern (SW) Japan is determined by applying double- difference tomography method to arrival time data for earthquakes obtained by a dense nationwide seismic network in Japan. A region of low S wave velocity and high Vp/Vs of several kilometers in thickness is recognized immediately above the region of intraslab seismicity in a wide area from Tokai to Kyushu. This characteristic layer dips shallowly in the direction of slab subduction. Compared with the upper surface of the Philippine Sea slab based on seismic reflection and refraction surveys on seven survey lines, we interpret that the low-Vs and high-Vp/Vs layer corresponds to the oceanic crust of the Philippine Sea slab. On the basis of the position of the low-Vs and high-Vp/Vs layer and the precisely relocated hypocenter distribution of intraslab earthquakes, the upper surface of the Philippine Sea slab is reliably determined for the entire area of SW Japan. Nonvolcanic deep low-frequency earthquakes that occurred associated with the subduction of the Philippine Sea slab are distributed along the isodepth contour of 30 km in SW Japan, except for the Tokai district where the depth of deep low-frequency earthquakes becomes gradually deeper toward northeast.