Seabed Fluid Flow: the Impact on Geology, Biology, and the Marine Environment Alan Judd and Martin Hovland Index More Information
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Canada's Active Western Margin
Geoscience Canada. Volume 3. Nunber 4 269 in the area of Washington and Oregon seemed necessary geometrically. This suggestion was reiterated by Tobin and Sykes (1968) in their study of the seismicity ofthe regionanddevelopedin established the presence and basic bathymetric trench at the foot of the Canada's Active configuration of an active spreading continental slope, the absence of a ocean ridge system ofl the west coast of clearly defined eastward dipping Beniofl Western Margin - Vancwver Island. The theory of the earthquake zone and the apparently geometrical mwement of rigid quiescent state of present volcanism The Case for lithospheric plates on a spherical earth have all contributed toward a (introducedas the 'paving stone' theory) widespreaa uncertalnfy as to whether Subduction was tirst ~ro~osedand tasted bv subddctlon 1s cbrrently taking place ~c~enziiand Parker (1967) using data (e.8.. Crosson. 1972: ~rivast&a,1973; R. P. Riddihough and R. D. Hyndnan from the N. Pacific and in the global Stacey. 1973). Past subduction, fran Victoria Geophysical Observatory, extension of the theory by Morgan several tens of m.y. ago until at leastone Earth Physics Branch, (1 968) this reglon again played a major or two m y. ago. IS more generally Department Energy, Mines and role Morgan alsoconcluded that a small accepted ana it seems to us that the Resources, block eitof theJuandeFuca ridge (the case for contemporary subduction, in a 5071 W. Saanich Rd. Juan de Fuca plate. Fig. 2) was moving large part, must beargued upona Victoria B. C. independently of the main Pacific plate. continuation into the present of the The possibility that theJuan de Fuca processes shown to be active in the Summary plate is now underthrustingNorth recent geological past. -
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. -
Geology 111 • Discovering Planet Earth • Steven Earle • 2010
H1) Earthquakes The plates that make up the earth's lithosphere are constantly in motion. The rate of motion is a few centimetres per year, or approximately 0.1 mm per day (about as fast as your fingernails grow). This does not mean, however, that the rocks present at the places where plates meet (e.g., convergent boundaries and transform faults) are constantly sliding past each other. Under some circumstances they do, but in most cases, particularly in the upper part of the crust, the friction between rocks at a boundary is great enough so that the two plates are locked together. As the plates themselves continue to move, deformation takes place in the rocks close to the locked boundary and strain builds up in the deformed rocks. This strain, or elastic deformation, represents potential energy stored within the rocks in the vicinity of the boundary between two plates. Eventually the strain will become so great that the friction and rock-strength that is preventing movement between the plates will be overcome, the rocks will break and the plates will suddenly slide past each other - producing an earthquake [see Fig. 10.4]. A huge amount of energy will suddenly be released, and will radiate away from the location of the earthquake in the form of deformation waves within the surrounding rock. S-waves (shear waves), and P-waves (compression waves) are known as body waves as they travel through the rock. As soon as this happens, much of the strain that had built up along the fault zone will be released1. -
Strathcona Park Trails Guide Special
STRATHCONA PARK TRAILS GUIDE SPECIAL Hiking Guide NootkaWILDWILD Island ISLEISLE Canada’sCanada’s WestWest CoastCoast AdventureAdventure MagazineMagazine ININ THETHE WAKEWAKE OFOF CAPTAINCAPTAIN VANCOUVERVANCOUVER A CLIMBER’S LIFELIFE CAVINGCAVING ININ THAILANDTHAILAND 3Chancesto WIN Apairoftickets to FREE ISSUE #12 AUGUST-SEPTEMBER, 2000 see page 26 for details www.wildislemagazine.bc.ca HIKE NOOTKA ISLAND The Resort at Cape Mudge Quadra Island BEACHFRONT CABIN . Only Getaway .95* September 16 - 30, 2000 $119 * based on quad occupancy 2 Bedroom With Jacuzzi Bathtub Gas Fireplace Kitchenette Us! 1-800-665-7745 [email protected] Tel: (250) 285-2042 Fax: (250) 285-2532 CCONTENTONTENTSS Cover: Curtis Lyon, South Ridge of Victoria Peak. Photo: Philip Stone BC Parks View Point p9 Volunteering in Paradise Gabe Jutras, Kwisatz Haderach 5.11d, Crest Creek Photo: Josie Boulding Linvin’ the Dream p10 Contents: The life of the Surfer at Long Beach. unsponsored climber Photo: Corrie Wright Strathcona Park p13 An overview of the hiking trails in BC’s oldest park Thai Caves p17 Islanders Abroad Underground adventure in Thailand Mt Colonel Foster p19 Guide to Vancouver Island’s alpine climbing mecca Benighted on Mt Klitsa p21 A lesson earned and a lesson learned In the Wake of Vancouver p22 The explorations of Cpt Vancouver on BC’s west coast. Happenings p26 Coming events on the west coast 3Chancesto WIN Apairoftickets to see page 26 for details west coast adventure magazine • www.wildislemagazine.bc.ca • CENTRE PULLOUT - NOOTKA ISLAND - HIKING -
Bcts Dcr, Dsc
Radio Channel Assignment Map DCR, DSC, DSI Version 10.8 BCTS January 30, 2015 BC Timber Sales W a d d i Strait of Georgia n g t o n G l a 1:400,000 c Date Saved: 2/3/2015 9:55:56 AM i S e c r a r Path: F:\tsg_root\GIS_Workspace\Mike\Radio_Frequency\Radio Frequency_2015.mxd C r e e k KLATTASINE BARB HO WARD A A T H K O l MTN H O M l LANDMAR K a i r r C e t l e a n R CAMBRIDG E t e R Wh i E C V A r I W R K A 7 HIDD EN W E J I C E F I E L D Homathko r C A IE R HEAK E T STANTON PLATEAU A G w r H B T TEAQ UAHAN U O S H N A UA Q A E 8 T H B R O I M Southgate S H T N O K A P CUMSACK O H GALLEO N GUNS IGHT R A E AQ V R E I T R r R I C V E R R MT E H V a RALEIG H SAWT rb S tan I t R o l R A u e E HO USE r o B R i y l I l V B E S E i 4 s i R h t h o 17 S p r O G a c l e Bear U FA LCO N T H G A Stafford R T E R E V D I I R c R SMIT H O e PEAK F Bear a KETA B l l F A T SIR FRANCIS DRAKE C S r MT 2 ke E LILLO OE T La P L rd P fo A af St Mellersh Creek PEAKS TO LO r R GRANITE C E T ST J OHN V MTN I I V E R R 12 R TAHUMMING R E F P i A l R Bute East PORTAL E e A L D S R r A E D PEAK O O A S I F R O T T Glendale 11 R T PRATT S N O N 3 S E O M P Phillip I I T Apple River T O L A B L R T H A I I SIRE NIA E U H V 11 ke Po M L i P E La so M K n C ne C R I N re N L w r ro ek G t B I OSMINGTO N I e e Call Inlet m 28 R l o r T e n T E I I k C Orford V R E l 18 V E a l 31 Toba I R C L R Fullmore 5 HEYDON R h R o George 30 Orford River I Burnt Mtn 16 I M V 12 V MATILPI Browne E GEORGE RIVER E R Bute West R H Brem 13 ke Bute East La G 26 don ey m H r l l e U R -
Mantle Flow Through the Northern Cordilleran Slab Window Revealed by Volcanic Geochemistry
Downloaded from geology.gsapubs.org on February 23, 2011 Mantle fl ow through the Northern Cordilleran slab window revealed by volcanic geochemistry Derek J. Thorkelson*, Julianne K. Madsen, and Christa L. Sluggett Department of Earth Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada ABSTRACT 180°W 135°W 90°W 45°W 0° The Northern Cordilleran slab window formed beneath west- ern Canada concurrently with the opening of the Californian slab N 60°N window beneath the southwestern United States, beginning in Late North Oligocene–Miocene time. A database of 3530 analyses from Miocene– American Holocene volcanoes along a 3500-km-long transect, from the north- Juan Vancouver Northern de ern Cascade Arc to the Aleutian Arc, was used to investigate mantle Cordilleran Fuca conditions in the Northern Cordilleran slab window. Using geochemi- Caribbean 30°N Californian Mexico Eurasian cal ratios sensitive to tectonic affi nity, such as Nb/Zr, we show that City and typical volcanic arc compositions in the Cascade and Aleutian sys- Central African American Cocos tems (derived from subduction-hydrated mantle) are separated by an Pacific 0° extensive volcanic fi eld with intraplate compositions (derived from La Paz relatively anhydrous mantle). This chemically defi ned region of intra- South Nazca American plate volcanism is spatially coincident with a geophysical model of 30°S the Northern Cordilleran slab window. We suggest that opening of Santiago the slab window triggered upwelling of anhydrous mantle and dis- Patagonian placement of the hydrous mantle wedge, which had developed during extensive early Cenozoic arc and backarc volcanism in western Can- Scotia Antarctic Antarctic 60°S ada. -
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. -
Tidally Controlled Gas Bubble Emissions: a Comprehensive 10.1002/2016GC006528 Study Using Long-Term Monitoring Data from the NEPTUNE
PUBLICATIONS Geochemistry, Geophysics, Geosystems RESEARCH ARTICLE Tidally controlled gas bubble emissions: A comprehensive 10.1002/2016GC006528 study using long-term monitoring data from the NEPTUNE Key Points: cabled observatory offshore Vancouver Island Continuous monitoring of transient gas bubble emissions over 1 year was Miriam Romer€ 1, Michael Riedel2, Martin Scherwath3, Martin Heesemann3, and George D. Spence4 enabled by the NEPTUNE cabled observatory 1 Flare onsets were triggered and MARUM-Center for Marine Environmental Sciences and Department of Geosciences, University of Bremen, Germany, controlled by tidally induced bottom 2GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany, 3Ocean Networks Canada, University of Victoria, British pressure changes Columbia, Canada, 4School of Earth and Ocean Sciences, University of Victoria, British Columbia, Canada Decreasing pressure allowing gas to migrate and shifting the CH4 solubility in pore waters leads to ebullition Abstract Long-term monitoring over 1 year revealed high temporal variability of gas emissions at a cold seep in 1250 m water depth offshore Vancouver Island, British Columbia. Data from the North East Pacific Supporting Information: Time series Underwater Networked Experiment observatory operated by Ocean Networks Canada were Figure S1 used. The site is equipped with a 260 kHz Imagenex sonar collecting hourly data, conductivity-temperature- Table S1 Movie S1 depth sensors, bottom pressure recorders, current meter, and an ocean bottom seismograph. This enables correlation of the data and analyzing trigger mechanisms and regulating criteria of gas discharge activity. Correspondence to: Three periods of gas emission activity were observed: (a) short activity phases of few hours lasting several M. Romer,€ months, (b) alternating activity and inactivity of up to several day-long phases each, and (c) a period of sev- [email protected] eral weeks of permanent activity. -
Forwards Geology,Seismology & Geotechnical
- c. x . @ , , C PUBLIC DOCUMENT ROOM , , , , UNITED STATES //- - / #,% O[ ~ !" o NUCLEAR REGULATORY COMMISSION 2 9 . 3 ; ,E WASHINGTON, D. C. 20555 @@ %...../ g e October 3, 1979 . a Valentine B. Deale, Esq., Chairman Dr. Frank F. Hooper Atomic Safety and Licensing Board School of Natural Resources 1001 Connecti:ut Avenue, N.W. University of Michigan Washington, DC 20036 Ann Arbor, MI 48109 Mr. Gustave A. Linenberger Atomic Safety and Licensing Board U.S. Nuclear Regulatory Commission Washington, DC 20555 In the Matter of Puget Sound Power & Light Company,~et al. (Skagit Nuclear Power Project, Units 1 and 2) ~~ - , Docket Nos. STN 50-522 and STN 50-523 Gentlemen: Enclosed is the NRC Staff's geology, seismology and geotechnical engineering review report which will be incorporated as Section 2.5 of the Final Supple- ment to the Staff's Safety Evaluation Report (SER). This report will also constitute the Staff's direct testimony on geology-seismology issues in this proceeding. The Staff's witnesses will consist of H. Lefevre, S. Wastler, Dr. J. Kelleher, and Dr. R. Regan. Also enclosed is the supplemental testi- many of Dr. Kelleher which addresses the Board request for testimony concerning the methods used by the Staff to estimate strong ground motion. The U.S. Geological Survey has assisted the NRC Staff in the review of the Skagit site. The U.S.G.S.'s review reports of February 23, 1978 and Sep- tember 17, 1979 (these reports have been previously distributed to the Board and parties), are attached as Appendix D to the Staff's report. -
Seismic Structure of the Endeavour Segment, Juan De Fuca Ridge: Correlations with Seismicity and Hydrothermal Activity E
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 112, B02401, doi:10.1029/2005JB004210, 2007 Click Here for Full Article Seismic structure of the Endeavour Segment, Juan de Fuca Ridge: Correlations with seismicity and hydrothermal activity E. M. Van Ark,1 R. S. Detrick,2 J. P. Canales,2 S. M. Carbotte,3 A. J. Harding,4 G. M. Kent,4 M. R. Nedimovic,3 W. S. D. Wilcock,5 J. B. Diebold,3 and J. M. Babcock4 Received 9 December 2005; revised 23 June 2006; accepted 21 September 2006; published 3 February 2007. [1] Multichannel seismic reflection data collected in July 2002 at the Endeavour Segment, Juan de Fuca Ridge, show a midcrustal reflector underlying all of the known high-temperature hydrothermal vent fields in this area. On the basis of the character and geometry of this reflection, its similarity to events at other spreading centers, and its polarity, we identify this as a reflection from one or more crustal magma bodies rather than from a hydrothermal cracking front interface. The Endeavour magma chamber reflector is found under the central, topographically shallow section of the segment at two-way traveltime (TWTT) values of 0.9–1.4 s (2.1–3.3 km) below the seafloor. It extends approximately 24 km along axis and is shallowest beneath the center of the segment and deepens toward the segment ends. On cross-axis lines the axial magma chamber (AMC) reflector is only 0.4–1.2 km wide and appears to dip 8–36° to the east. While a magma chamber underlies all known Endeavour high-temperature hydrothermal vent fields, AMC depth is not a dominant factor in determining vent fluid properties. -
Determining Contemporary and Historical Sediment Sources in A
Journal of Soils and Sediments https://doi.org/10.1007/s11368-019-02299-2 SEDIMENT FINGERPRINTING IN THE CRITICAL ZONE Determining contemporary and historical sediment sources in a large drainage basin impacted by cumulative effects: the regulated Nechako River, British Columbia, Canada David Gateuille1,2 & Philip N. Owens1,3 & Ellen L. Petticrew1,4 & Barry P. Booth1 & Todd D. French3,4 & Stephen J. Déry1,3 Received: 31 August 2018 /Accepted: 3 March 2019 # The Author(s) 2019 Abstract Purpose Sediment dynamics in most large river basins are influenced by a variety of different natural and anthropogenic pressures, and disentangling these cumulative effects remains a challenge. This study determined the contemporary and historical sources of fine-grained (< 63-μm) sediment in a large, regulated river basin and linked changes in sources to activities in the basin. The river has seen declines in chinook salmon, sockeye salmon, and the endangered Nechako white sturgeon populations, and sediment (both fine-grained and sands) transport and deposition have been identified as potential causes of these declines. Materials and methods Samples of suspended sediment and potential source materials were collected from numerous sites distributed throughout the upper Nechako River Basin in British Columbia, Canada. A floodplain sediment core was also collected in order to reconstruct sediment sources over the last ~ 70 years. Discriminating fingerprint properties were used within the MixSIAR model to apportion sources among sub-basins and land-use types. Results were compared to records of precipi- tation and Nechako River discharge trends, and to changes in landscape development. Results and discussion Contributions from the erosion of channel banks dominated the suspended sediment load at most sites.