Mapping Absolute Migration of Global Mid-Ocean Ridges Since 80 Ma to Present
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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. -
51. Breakup and Seafloor Spreading Between the Kerguelen Plateau-Labuan Basin and the Broken Ridge-Diamantina Zone1
Wise, S. W., Jr., Schlich, R., et al., 1992 Proceedings of the Ocean Drilling Program, Scientific Results, Vol. 120 51. BREAKUP AND SEAFLOOR SPREADING BETWEEN THE KERGUELEN PLATEAU-LABUAN BASIN AND THE BROKEN RIDGE-DIAMANTINA ZONE1 Marc Munschy,2 Jerome Dyment,2 Marie Odile Boulanger,2 Daniel Boulanger,2 Jean Daniel Tissot,2 Roland Schlich,2 Yair Rotstein,2,3 and Millard F. Coffin4 ABSTRACT Using all available geophysical data and an interactive graphic software, we determined the structural scheme of the Australian-Antarctic and South Australian basins between the Kerguelen Plateau and Broken Ridge. Four JOIDES Resolution transit lines between Australia and the Kerguelen Plateau were used to study the detailed pattern of seafloor spreading at the Southeast Indian Ridge and the breakup history between the Kerguelen Plateau and Broken Ridge. The development of rifting between the Kerguelen Plateau-Labuan Basin and the Broken Ridge-Diamantina Zone, and the evolution of the Southeast Indian Ridge can be summarized as follows: 1. From 96 to 46 Ma, slow spreading occurred between Antarctica and Australia; the Kerguelen Plateau, Labuan Basin, and Diamantina Zone stretched at 88-87 Ma and 69-66 Ma. 2. From 46 to 43 Ma, the breakup between the Southern Kerguelen Plateau and the Diamantina Zone propagated westward at a velocity of about 300 km/m.y. The breakup between the Northern Kerguelen Plateau and Broken Ridge occurred between 43.8 and 42.9 Ma. 3. After 43 Ma, volcanic activity developed on the Northern Kerguelen Plateau and at the southern end of the Ninetyeast Ridge. Lava flows obscured the boundaries of the Northern Kerguelen Plateau north of 48°S and of the Ninetyeast Ridge south of 32°S, covering part of the newly created oceanic crust. -
OCEAN/ESS 410 1 Lab 3. the Juan De Fuca Plate Please Write out Your
OCEAN/ESS 410 Lab 3. The Juan de Fuca Plate Please write out your answers on a separate sheet of paper. In this exercise you are going to be looking at the bathymetry of the Juan de Fuca plate region, identifying interesting features and their characteristics, and attempting to interpret what you see. Some of the questions may be difficult for you to answer now (although hopefully not at the end of the Quarter) – part of the objective is to get you to look carefully at the maps and think rather that immediately writing down an answer. The Instructor and TAs will be coming around the lab answering questions. Figure 1 shows the plate boundaries for the Juan de Fuca plate region and you will use this as your road map as you explore the Juan de Fuca plate with the program GeoMapApp, a versatile program that is used by researchers to look at bathymetry and other seafloor data. To run GeoMapApp do the following 1. Start GeoMapApp on the lab computer from the Start menu or from the Desktop Icon if you have one. If it asks you to install a new version you do not have to. 2. Select the default Mercator Base Map (left hand map) 3. Learn to use the “Zoom In”, “Zoom Out” and “Pan the Map” tools. You can use the “Zoom In” tool either by clicking on the map or holding the mouse button down to rubber-band a box of interest. The Overlays menu allows you to add a Distance Scale and Color Bar. -
Recent Movements of the Juan De Fuca Plate System
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 89, NO. B8, PAGES 6980-6994, AUGUST 10, 1984 Recent Movements of the Juan de Fuca Plate System ROBIN RIDDIHOUGH! Earth PhysicsBranch, Pacific GeoscienceCentre, Departmentof Energy, Mines and Resources Sidney,British Columbia Analysis of the magnetic anomalies of the Juan de Fuca plate system allows instantaneouspoles of rotation relative to the Pacific plate to be calculatedfrom 7 Ma to the present.By combiningthese with global solutions for Pacific/America and "absolute" (relative to hot spot) motions, a plate motion sequencecan be constructed.This sequenceshows that both absolute motions and motions relative to America are characterizedby slower velocitieswhere younger and more buoyant material enters the convergencezone: "pivoting subduction."The resistanceprovided by the youngestportion of the Juan de Fuca plate apparently resulted in its detachmentat 4 Ma as the independentExplorer plate. In relation to the hot spot framework, this plate almost immediately began to rotate clockwisearound a pole close to itself such that its translational movement into the mantle virtually ceased.After 4 Ma the remainder of the Juan de Fuca plate adjusted its motion in responseto the fact that the youngest material entering the subductionzone was now to the south. Differencesin seismicityand recent uplift betweennorthern and southernVancouver Island may reflect a distinction in tectonicstyle betweenthe "normal" subductionof the Juan de Fuca plate to the south and a complex "underplating"occurring as the Explorer plate is overriddenby the continent.The history of the Explorer plate may exemplifythe conditionsunder which the self-drivingforces of small subductingplates are overcomeby the influenceof larger, adjacent plates. The recent rapid migration of the absolutepole of rotation of the Juan de Fuca plate toward the plate suggeststhat it, too, may be nearingthis condition. -
The Official Magazine of The
OceTHE OFFICIALa MAGAZINEn ogOF THE OCEANOGRAPHYra SOCIETYphy CITATION Smith, L.M., J.A. Barth, D.S. Kelley, A. Plueddemann, I. Rodero, G.A. Ulses, M.F. Vardaro, and R. Weller. 2018. The Ocean Observatories Initiative. Oceanography 31(1):16–35, https://doi.org/10.5670/oceanog.2018.105. DOI https://doi.org/10.5670/oceanog.2018.105 COPYRIGHT This article has been published in Oceanography, Volume 31, Number 1, a quarterly journal of The Oceanography Society. Copyright 2018 by The Oceanography Society. All rights reserved. USAGE Permission is granted to copy this article for use in teaching and research. Republication, systematic reproduction, or collective redistribution of any portion of this article by photocopy machine, reposting, or other means is permitted only with the approval of The Oceanography Society. Send all correspondence to: [email protected] or The Oceanography Society, PO Box 1931, Rockville, MD 20849-1931, USA. DOWNLOADED FROM HTTP://TOS.ORG/OCEANOGRAPHY SPECIAL ISSUE ON THE OCEAN OBSERVATORIES INITIATIVE The Ocean Observatories Initiative By Leslie M. Smith, John A. Barth, Deborah S. Kelley, Al Plueddemann, Ivan Rodero, Greg A. Ulses, Michael F. Vardaro, and Robert Weller ABSTRACT. The Ocean Observatories Initiative (OOI) is an integrated suite of instrumentation used in the OOI. The instrumented platforms and discrete instruments that measure physical, chemical, third section outlines data flow from geological, and biological properties from the seafloor to the sea surface. The OOI ocean platforms and instrumentation to provides data to address large-scale scientific challenges such as coastal ocean dynamics, users and discusses quality control pro- climate and ecosystem health, the global carbon cycle, and linkages among seafloor cedures. -
High-Silica Lava Morphology at Ocean Spreading Ridges: Machine-Learning Seafloor Classification at Alarcon Rise
Article High-Silica Lava Morphology at Ocean Spreading Ridges: Machine-Learning Seafloor Classification at Alarcon Rise Christina H. Maschmeyer 1,†, Scott M. White 1,*, Brian M. Dreyer 2 and David A. Clague 3 1 School of the Earth, Ocean and Environment, University of South Carolina, Columbia, SC 29208, USA; [email protected] 2 Institute of Marine Sciences, University of California, Santa Cruz, CA 95064, USA; [email protected] 3 Monterey Bay Aquarium Research Institute, Moss Landing, CA 95039, USA; [email protected] † Now at: Fugro USA Marine, Inc. Geoconsulting Exploration, 6100 Hillcroft Ave, Houston, TX 77081, USA * Correspondence: [email protected] Received 31 March 2019; Accepted 28 May 2019; Published: 1 June 2019 Abstract: The oceanic crust consists mostly of basalt, but more evolved compositions may be far more common than previously thought. To aid in distinguishing rhyolite from basaltic lava and help guide sampling and understand spatial distribution, we constructed a classifier using neural networks and fuzzy inference to recognize rhyolite from its lava morphology in sonar data. The Alarcon Rise is ideal to study the relationship between lava flow morphology and composition, because it exhibits a full range of lava compositions in a well‐mapped ocean ridge segment. This study shows that the most dramatic geomorphic threshold in submarine lava separates rhyolitic lava from lower‐silica compositions. Extremely viscous rhyolite erupts as jagged lobes and lava branches in submarine environments. An automated classification of sonar data is a useful first‐order tool to differentiate submarine rhyolite flows from widespread basalts, yielding insights into eruption, emplacement, and architecture of the ocean crust. -
Petrological Characteristics and Genesis of the Central Indian Ocean Basin Basalts
Page | 1 Author version: Acta Geol. Sin., vol.86(5); 2012; 1154-1170 Petrological characteristics and genesis of the Central Indian Ocean Basin basalts PRANAB DAS1, SRIDHAR D. IYER1 AND SUGATA HAZRA2 1NATIONAL INSTITUTE OF OCEANOGRAPHY (COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH) DONA PAULA, GOA – 403004 INDIA 2SCHOOL OF OCEANOGRAPHIC STUDIES, JADAVPUR UNIVERSITY KOLKATA – 700 032 INDIA ABSTRACT The Central Indian Ocean Basin (CIOB) basalts are plagioclase rich while olivine and pyroxene T are very few. The analyses of forty five samples reveal high FeO (~10-18 wt%) and TiO2 (~1.4-2.7 wt%) indicating these a ferrobasaltic affinity. The basalts have typically high incompatible elements (Zr 63-228 ppm; Nb ~1-5 ppm; Ba ~15-78 ppm; La ~3-16 ppm), a similar U/Pb (0.02-0.4) ratio as the N- MORB (0.16±0.07) but the Ba/Nb (12.5-53) ratio is much higher than that of the normal mid-oceanic ridge basalt (N-MORB) (~5.7) and Primitive Mantle (9.56). Interestingly almost all of the basalts have negative Eu anomaly (Eu/Eu* = 0.78-1.00) that may have resulted by the removal of feldspar and pyroxene during crystal fractionation. These compositional variations suggest that the basalts were derived through fractional crystallisation together with low partial melting of a shallow seated magma. Key words: Basalts; CIOB; genesis Page | 2 1. INTRODUCTION The Indian Ocean is exemplified by the Central Indian Ridge (CIR), Southwest Indian Ridge (SWIR) and Southeast Indian Ridge (SEIR). The Central Indian Ocean Basin (CIOB) extends from the Ninetyeast Ridge in the east to the south of the Chagos–Lacaddive Ridge and the CIR in the west and is bounded in the south by the Rodriguez Triple Junction and the northern part of the SEIR and in the north by India and Sri Lanka. -
Winter 2006 Newsletter
DEEP OCEAN EXPLORATION INSTITUTE INVESTIGATING EARTH’S DYNAMIC PROCESSES Winter 2006 Newsletter the National Science Foundation. In undertaken by our students. Matt’s February 2006, I was asked to participate award by the AGU reflects the very high in a conference on the Oceans in the caliber of our students and acknowledges Nuclear Age at UC Berkeley, where their achievements. there was considerable discussion about The seafloor geodetic experiment the policy and science of nuclear waste being carried out by Jeff McGuire and disposal in the oceans – past and future. Mark Behn underscores how important Public and educational outreach is also technology development is to conducting a focus of DOEI through the Dive and world-class experiments on fundamental Discover™ Web site. Dive and Discover™ earth and ocean science problems. Their (http://www.divediscover.whoi.edu) experiment is unique. It will provide Dan and his able assistant Riley provides a fun and interactive educational not only crucial tests of hypotheses about Director’s Notes program for K-12 students and the how ocean island flanks deform, but their general public. In 2005, Dive and instrumentation will also play a major In 2005, DOEI funded six new Discover™ hosted Expedition 9, a revisit role in the understanding of oceanic research projects, with investigators to the Galapagos Rift that included Alvin transform behavior and, by analogy, how representing all WHOI departments dives and deep-sea camera exploration faults behave and how their movements and encompassing all of the Institute’s for hydrothermal vents. Currently, Dive may be better predicted. research themes - Seafloor Observatory and Discover™ Expedition 10 is ongoing As I write these notes, many investi- Science, Fluid Flow in Geologic Systems, in the Antarctic’s Southern Ocean. -
Insights on the Indian Ocean Tectonics and Geophysics Supported by GMT Polina Lemenkova
Insights on the Indian Ocean tectonics and geophysics supported by GMT Polina Lemenkova To cite this version: Polina Lemenkova. Insights on the Indian Ocean tectonics and geophysics supported by GMT. Riscuri si Catastrofe, ”Babes-Bolyai” University from Cluj-Napoca, Faculty of Geography, 2020, 27 (2), pp.67- 83. 10.24193/RCJ2020_12. hal-03033533 HAL Id: hal-03033533 https://hal.archives-ouvertes.fr/hal-03033533 Submitted on 1 Dec 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Distributed under a Creative Commons Attribution| 4.0 International License Riscuri și catastrofe, an XX, vol, 27 nr. 2/2020 INSIGHTS ON THE INDIAN OCEAN TECTONICS AND GEOPHYSICS SUPPORTED BY GMT POLINA LEMENKOVA1 Abstract. Insights on the Indian Ocean Tectonics and Geophysics Supported by GMT. This paper presented analyzed and summarized data on geological and geophysical settings about the tectonics and geological structure of the seafloor of the Indian Ocean by thematic visualization of the topographic, geophysical and geo- logical data. The seafloor topography of the Indian Ocean is very complex which includes underwater hills, isolated mountains, underwater canyons, abyssal and ac- cumulative plains, trenches. Complex geological settings explain seismic activity, repetitive earthquakes, and tsunami. -
Seafloor Hydrothermal Activity Around a Large Non-Transform
Journal of Marine Science and Engineering Article Seafloor Hydrothermal Activity around a Large Non-Transform Discontinuity along Ultraslow-Spreading Southwest Indian Ridge (48.1–48.7◦ E) Dong Chen 1,2, Chunhui Tao 2,3,*, Yuan Wang 2, Sheng Chen 4, Jin Liang 2, Shili Liao 2 and Teng Ding 1 1 Institute of Marine Geology, College of Oceanography, Hohai University, Nanjing 210098, China; [email protected] (D.C.); [email protected] (T.D.) 2 Key Laboratory of Submarine Geosciences, SOA & Second Institute of Oceanography, MNR, Hangzhou 310012, China; [email protected] (Y.W.); [email protected] (J.L.); [email protected] (S.L.) 3 School of Oceanography, Shanghai Jiao Tong University, Shanghai 200240, China 4 Ocean Technology and Equipment Research Center, School of Mechanical Engineering, Hangzhou Dianzi University, Hangzhou 310018, China; [email protected] * Correspondence: [email protected] Abstract: Non-transform discontinuity (NTD) is one category of tectonic units along slow- and ultraslow-spreading ridges. Some NTD-related hydrothermal fields that may reflect different driving mechanisms have been documented along slow-spreading ridges, but the discrete survey strategy makes it hard to evaluate the incidence of hydrothermal activity. On ultraslow-spreading ridges, fewer NTD-related hydrothermal activities were reported. Factors contributing to the occurrence of hydrothermal activities at NTDs and whether they could be potential targets for hydrothermal explo- Citation: Chen, D.; Tao, C.; Wang, Y.; Chen, S.; Liang, J.; Liao, S.; Ding, T. ration are poorly known. Combining turbidity and oxidation reduction potential (ORP) sensors with Seafloor Hydrothermal Activity a near-bottom camera, Chinese Dayang cruises from 2014 to 2018 have conducted systematic towed around a Large Non-Transform surveys for hydrothermal activity around a large NTD along the ultraslow-spreading Southwest ◦ Discontinuity along Indian Ridge (SWIR, 48.1–48.7 E). -
Geophysical Journal International
Geophysical Journal International Geophys. J. Int. (2013) doi: 10.1093/gji/ggt372 Geophysical Journal International Advance Access published October 11, 2013 Cretaceous to present kinematics of the Indian, African and Seychelles plates Graeme Eagles∗ and Ha H. Hoang Department of Earth Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, United Kingdom. E-mail: [email protected] Downloaded from Accepted 2013 September 16. Received 2013 September 13; in original form 2012 November 12 SUMMARY An iterative inverse model of seafloor spreading data from the Mascarene and Madagascar http://gji.oxfordjournals.org/ basins and the flanks of the Carlsberg Ridge describes a continuous history of Indian–African Plate divergence since 84 Ma. Visual-fit modelling of conjugate magnetic anomaly data from near the Seychelles platform and Laxmi Ridge documents rapid rotation of a Seychelles Plate about a nearby Euler pole in Palaeocene times. As the Euler pole migrated during this rotation, the Amirante Trench on the western side of the plate accommodated first convergence and later divergence with the African Plate. The unusual present-day morphology of the Amirante GJI Geodynamics and tectonics Trench and neighbouring Amirante Banks can be related to crustal thickening by thrusting and at Alfred Wegener Institut fuer Polar- und Meeresforschung Bibliothek on October 11, 2013 folding during the convergent phase and the subsequent development of a spreading centre with a median valley during the divergent phase. The model fits FZ trends in the north Arabian and east Somali basins, suggesting that they formed in India–Africa Plate divergence. Seafloor fabric in and between the basins shows that they initially hosted a segmented spreading ridge that accommodated slow plate divergence until 71–69 Ma, and that upon arrival of the Deccan–Reunion´ plume and an increase to faster plate divergence rates in the period 69–65 Ma, segments of the ridge lengthened and propagated. -
21. Tectonic Evolution of the Atlantis Ii Fracture Zone1
Von Herzen, R.P., Robinson, P.T., et al., 1991 Proceedings of the Ocean Drilling Program, Scientific Results,Vol. 118 21. TECTONIC EVOLUTION OF THE ATLANTIS II FRACTURE ZONE1 Henry J.B. Dick,2 Hans Schouten,2 Peter S. Meyer,2 David G. Gallo,2 Hugh Bergh,3 Robert Tyce,4 Phillipe Patriat,5 Kevin T.M. Johnson,2 Jon Snow,2 and Andrew Fisher6 ABSTRACT SeaBeam echo sounding, seismic reflection, magnetics, and gravity profiles were run along closely spaced tracks (5 km) parallel to the Atlantis II Fracture Zone on the Southwest Indian Ridge, giving 80% bathymetric coverage of a 30- × 170-nmi strip centered over the fracture zone. The southern and northern rift valleys of the ridge were clearly defined and offset north-south by 199 km. The rift valleys are typical of those found elsewhere on the Southwest Indian Ridge, with relief of more than 2200 m and widths from 22 to 38 km. The ridge-transform intersections are marked by deep nodal basins lying on the transform side of the neovolcanic zone that defines the present-day spreading axis. The walls of the transform generally are steep (25°-40°), although locally, they can be more subdued. The deepest point in the transform is 6480 m in the southern nodal basin, and the shallowest is an uplifted wave-cut terrace that exposes plutonic rocks from the deepest layer of the ocean crust at 700 m. The transform valley is bisected by a 1.5-km-high median tectonic ridge that extends from the northern ridge-transform intersection to the midpoint of the active transform.