DOCSLIB.ORG

The Subduction Initiation Stage of the Wilson Cycle

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Subduction Initiation Stage of the Wilson Cycle Downloaded from http://sp.lyellcollection.org/ by guest on February 20, 2018 The subduction initiation stage of the Wilson cycle ROBERT HALL SE Asia Research Group, Department of Earth Sciences, Royal Holloway University of London, Egham, Surrey, TW20 0EX, UK [email protected] R.H., 0000-0003-1693-6914 Abstract: In the Wilson cycle, there is a change from an opening to a closing ocean when subduction begins. Subduction initiation is commonly identified as a major problem in plate tectonics and is said to be nowhere observable, yet there are many young subduction zones at the west Pacific margins and in eastern Indonesia. Few studies have considered these examples. Banda subduction developed by the eastwards propagation of the Java trench into an oceanic embayment by tearing along a former ocean–continent boundary. The earlier subducted slab provided the driving force to drag down unsubducted oceanic lithosphere. Although this process may be common, it does not account for young subduction zones near Sulawesi at different stages of develop- ment. Subduction began there at the edges of ocean basins, not at former spreading centres or transforms. It initiated at a point where there were major differences in elevation between the ocean floor and the adjacent hot, weak and thickened arc/continental crust. The age of the ocean crust appears to be unimportant. A close relationship with extension is marked by the dramatic elevation of land, the exhumation of deep crust and the spectacular subsidence of basins, raising questions about the time required to move from no subduction to active subduction, and how initiation can be identified in the geological record. A crucial stage in the Wilson cycle is the change the unusual geochemistry of volcanic rocks such as from opening to closing of an ocean basin and the boninites, and the growth of arc and continental development of subduction. There are many publica- crust. However, we now know that the West Philip- tions on the initiation of subduction and it is not the pine basin must have opened in a former Cretaceous intention of this paper to review previous work. Pro- arc setting (e.g. Ozima et al. 1977; Shiki et al. 1977; ducing new trenches is considered difficult, and sub- Mizuno et al. 1979; Tokuyama 1985; Tokuyama duction initiation is commonly identified as a major et al. 1986; Hall et al. 1995b; Deschamps & Lalle- problem in plate tectonics (e.g. McKenzie 1977), mand 2002; Arculus et al. 2015), palaeomagnetic ‘not easily answered by direct observation’. Gerya work has cast doubt on the reconstructions on (2010) identified at least 14 hypothetical explana- which the original tectonic models were based (e.g. tions and commented that the ‘major obstacle … to Haston & Fuller 1991; Ali & Hall 1995; Hall et al. investigate subduction initiation by observation is 1995a, c; Queano et al. 2007) and the postulated the absence of definite knowledge about localities age difference across the transforms are much larger where subduction possibly starts’. It has become than those observed anywhere in the current global widely accepted that the initiation of subduction can- ridge system (e.g. Norton 2000; Müller et al. not be observed and the majority of publications on 2008). Other models have suggested the initiation of the topic have advanced possible models or, in recent subduction at an oceanic spreading centre based on years, have described numerical or analogue model- studies of the Oman ophiolite (e.g. Coleman 1981; ling studies believed to offer explanations. Boudier et al. 1988; Hacker 1991), but these too Among the many models and possible settings are controversial (e.g. Searle & Cox 1999; Warren for the initiation of subduction, most of which have et al. 2005, 2007; Boudier & Nicolas 2007). What been reviewed by Stern (2004), two in particular is certainly true is that in neither case can the process receive much attention and are commonly linked to of the initiation of subduction, which occurred 50 the west Pacific and ophiolite formation and/or (Izu–Bonin–Marianas) or 90 myr ago (Oman), be emplacement. One early proposal was the initiation observed. Testing the models is therefore difficult. of subduction at a transform in a major ocean basin In contrast, there are many young subduction (e.g. Uyeda & Ben-Avraham 1972; Casey & zones at the western Pacific margins and in eastern Dewey 1984; Stern & Bloomer 1992) with a type Indonesia. Almost all of these have formed since area in the Izu–Bonin–Marianas arc. This model has the Early Miocene, i.e. in the last c. 20 myr, but linked forearcs, supra-subduction zone ophiolites, they generally receive little or no attention. Karig From:WILSON, R. W., HOUSEMAN, G. A., MCCAFFREY, K. J. W., DORÉ,A.G.&BUITER, S. J. H. (eds) Fifty Years of the Wilson Cycle Concept in Plate Tectonics. Geological Society, London, Special Publications, 470, https://doi.org/10.1144/SP470.3 © 2018 The Author(s). This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/). Published by The Geological Society of London. Publishing disclaimer: www.geolsoc.org.uk/pub_ethics Downloaded from http://sp.lyellcollection.org/ by guest on February 20, 2018 R. HALL (1982) provided one of the few accounts that dis- (Hall 2012). It resumed in the Eocene at c. 45 Ma cussed the initiation of subduction in some of at the Sunda trench as Australia began to move rap- them. None of the subduction zones initiated at idly northwards (Smyth et al. 2008). It is impossible active spreading centres or at transforms. All formed now to identify where and how this subduction initi- at the margins of ocean basins. Figure 1 shows those ated, but it is most likely that there was eastwards between the northern Philippines and western New propagation from the eastern end of subduction Guinea. I contend here that different stages in the zones north of India, where there had been two sub- development of subduction, from the earliest stages parallel subduction zones (Jagoutz et al. 2015) from of the downward flexure of oceanic crust to the for- the Late Cretaceous until the Late Eocene. mation of a well-defined Benioff zone, can be During the Paleogene there was a long north- observed in the eastern Indonesia and southern Phil- dipping subduction zone, traceable along the south ippines region. This paper does not offer a detailed Eurasian margin southeastwards from Sumatra and physical or mechanical model, but summarizes south of Java to Sumba (Fig. 2a). This was offset observations identifying features that may be essen- to the NE (Fig. 2a) along a transform segment to tial for the initiation of subduction and that could be join a subduction zone beneath the North Sulawesi incorporated in future modelling studies. Here I volcanic arc on the south side of the Celebes Sea, focus on two ways and areas in which subduction and from there into the west Pacific along the south- initiated. ern boundary of the Philippine Sea plate. (1) The Banda region provides an example of sub- The form of the NW Australian margin was duction that propagated from an existing sub- important for the Cenozoic history of eastern Indone- duction zone. This is one relatively easy way sia. Jurassic rifting had formed an oceanic embay- in which new subduction zones may develop. ment, the Banda embayment, within the NW However, this mechanism does not account Australian margin, which contained oceanic crust for the many young subduction zones nearby, of Late Jurassic age, a small part of which is pre- which are not fully connected together. served today in the Argo abyssal plain. The rifting (2) There are several subduction zones in the left an elongate promontory of Australian conti- region around Sulawesi, each of which devel- nental crust, the Sula Spur (Klompé 1954), which oped independently from a point. The Sula extended west from New Guinea on the north side deep, Tolo trough, Cotobato trench and of the Banda embayment (Fig. 2a). North Sulawesi trench (Fig. 1) are proposed In the Early Miocene, at c. 23 Ma, the Sula Spur as successive stages of development and to began to collide with the North Sulawesi volcanic arc fi have initiated in an extensional setting. The and was the rst part of the Australian continent to Philippine trench shares many of the features make contact with the SE Asian margin. Ophiolites of these young subduction zones and also in East Sulawesi (Kündig 1956; Silver et al. 1983), developed from a point, but was more likely derived from the ocean north of the Sula Spur, initiated by contraction. were thrust southwards onto the continental crust of the Sula Spur in East Sulawesi beneath the North Sulawesi forearc. After this collision, contin- Regional background ued northwards movement of Australia was absorbed in several ways, including the subduction The size of the Indonesian region is often over- of oceanic crust at the Java trench, the broad non- looked, but it is similar to that of western Europe rigid counter-clockwise rotation of SE Asia (Borneo, between Ireland and Turkey or to the coterminous West Sulawesi, Java) and contraction and uplift in USA (Hall 2017). Describing its geological history East and SE Sulawesi. is therefore a challenge. Interested readers may As Australia moved north, subduction at the Java begin with the references cited here as an introduc- trench became aligned with the northern margin of tion to this fascinating and geologically important the Banda embayment. At c. 17 Ma, from the east region. I give a brief summary of the main features end of the Java trench, a tear propagated eastwards relevant to understanding the Neogene development along the continent–ocean boundary from the west- of eastern Indonesia, illustrated in Figure 2, to pro- ern end of the Sula Spur.
Load more

Recommended publications
  • Preliminary Catalog of the Sedimentary Basins of the United States
    Preliminary Catalog of the Sedimentary Basins of the United States By James L. Coleman, Jr., and Steven M. Cahan Open-File Report 2012–1111 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior KEN SALAZAR, Secretary U.S. Geological Survey Marcia K. McNutt, Director U.S. Geological Survey, Reston, Virginia: 2012 For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1–888–ASK–USGS. For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprod To order this and other USGS information products, visit http://store.usgs.gov Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner. Suggested citation: Coleman, J.L., Jr., and Cahan, S.M., 2012, Preliminary catalog of the sedimentary basins of the United States: U.S. Geological Survey Open-File Report 2012–1111, 27 p. (plus 4 figures and 1 table available as separate files) Available online at http://pubs.usgs.gov/of/2012/1111/. iii Contents Abstract ...........................................................................................................................................................1
    [Show full text]
  • Bottom Water and Bottom Configuration of the Great Atlantic Deeps. (1) (2)
    bOTTOM WATER AND bOTTOM CONFIGURATION OF THE GREAT ATLANTIC DEEPS. (1) (2). (Extract from the Results of the German Atlantic Expedition) by G e o r g WUST. The problem of the origin and distribution of bottom water has been discussed from early times, and often. This results from the fact that more abundant materials of observation exist for the bottom than for the deep layers, because measurements of bottom temperature have been taken not only by exploring vessels, but also by hydro- graphic and cable-laying ships. The remarkably low temperatures of nearly o° C. on the bottom, which were confirmed on each occasion, also early served as the principal foun­ dation of the hypothesis of the polar origin of the bottom water. The polar bottom currents are consequently members of the deep oceanic circulation, the existence of which had been deduced from the distribution of the temperature before the Challenger expedi­ tion. If it had been thought before that time that the Arctic and Antarctic currents showed roughly the same development and met at the equator, it became clear, after the Challenger and Gazelle observations, that the principal mass of the bottom waters of the great oceans comes from the Antarctic Basin ; that in the Atlantic Ocean this bottom current chiefly leads into the western trough ; and that it can still be detected in the form of a cold stream as far as the equator (in its last ramifications it even passes the equator and reaches the North Atlantic). These expeditions have also shown the value of bottom temperatures for revealing the first magnitude shapes of the ocean bottom, a value which has been proved for the Atlantic Ocean by two examples which have become classic.
    [Show full text]
  • Tsunamigenic Earthquakes
    Fifteen Years of (Major to Great) Tsunamigenic Earthquakes F Romano, S Lorito, and A Piatanesi, Istituto Nazionale di Geofisica e Vulcanologia, Roma, Italy T Lay, Earth and Planetary Sciences Department, University of California Santa Cruz, Santa Cruz, CA, United States © 2020 Elsevier Inc. All rights reserved. Tsunamis, Seismically Induced 1 Fifteen Years of Major to Great Tsunamigenic Earthquakes 3 The Study of Tsunamigenic Earthquakes 3 Megathrust Tsunamigenic Earthquakes 4 The Sunda 2004–10 Sequence in the Indian Ocean 4 Peru 2007 5 Maule 2010 5 Tohoku 2011 5 Santa Cruz 2013 6 Iquique 2014 6 Illapel 2015 6 Tsunamigenic Doublets 7 Kurils 2006–07 7 Samoa 2009 7 Tsunami Earthquakes 7 Java 2006 8 Mentawai 2010 8 Recent Special Cases 8 Sumatra 2012 8 Solomon 2007 8 Haida Gwaii 2012 9 Kaikoura 2016 9 Mexico 2017 9 Palu 2018 9 Conclusions 10 References 10 Further Reading 12 Tsunamis, Seismically Induced Tsunamis are a series of long gravity waves generated by the displacement of a significant volume of water that propagating in the sea, under the action of the gravity force, returns in its original equilibrium position. Differently from the common wind waves, tsunamis are characterized by large wavelengths (ranging from tens to hundreds of km) and long periods (ranging from minutes to hours). Several natural phenomena such as earthquakes, landslides, volcanic eruptions, the rapid change of atmospheric pressure (meteotsunami), or asteroids impacts can be the source of a tsunami; among these, the most frequent is represented by the earthquakes. Most of the very tsunamigenic earthquakes occur nearby the Earth convergent boundaries (Fig.
    [Show full text]
  • Kinematics and Extent of the Piemont-Liguria Basin
    https://doi.org/10.5194/se-2020-161 Preprint. Discussion started: 8 October 2020 c Author(s) 2020. CC BY 4.0 License. Kinematics and extent of the Piemont-Liguria Basin – implications for subduction processes in the Alps Eline Le Breton1, Sascha Brune2,3, Kamil Ustaszewski4, Sabin Zahirovic5, Maria Seton5, R. Dietmar Müller5 5 1Department of Earth Sciences, Freie Universität Berlin, Germany 2Geodynamic Modelling Section, German Research Centre for Geosciences, GFZ Potsdam, Germany 3Institute of Geosciences, University of Potsdam, Potsdam, Germany 4Institute for Geological Sciences, Friedrich-Schiller-Universität Jena, Germany 10 5EarthByte Group, School of Geosciences, The University of Sydney, NSW 2006, Australia Correspondence to: Eline Le Breton ([email protected]) Abstract. Assessing the size of a former ocean, of which only remnants are found in mountain belts, is challenging but crucial to understand subduction and exhumation processes. Here we present new constraints on the opening and width of the Piemont- Liguria (PL) Ocean, known as the Alpine Tethys together with the Valais Basin. We use a regional tectonic reconstruction of 15 the Western Mediterranean-Alpine area, implemented into a global plate motion model with lithospheric deformation, and 2D thermo-mechanical modelling of the rifting phase to test our kinematic reconstructions for geodynamic consistency. Our model fits well with independent datasets (i.e. ages of syn-rift sediments, rift-related fault activity and mafic rocks) and shows that the PL Basin opened in four stages: (1) Rifting of the proximal continental margin in Early Jurassic (200-180 Ma), (2) Hyper- extension of the distal margin in Early-Middle Jurassic (180-165 Ma), (3) Ocean-Continent Transition (OCT) formation with 20 mantle exhumation and MORB-type magmatism in Middle-Late Jurassic (165-154 Ma), (4) Break-up and “mature” oceanic spreading mostly in Late Jurassic (154-145 Ma).
    [Show full text]
  • Waves of Destruction in the East Indies: the Wichmann Catalogue of Earthquakes and Tsunami in the Indonesian Region from 1538 to 1877
    Downloaded from http://sp.lyellcollection.org/ by guest on May 24, 2016 Waves of destruction in the East Indies: the Wichmann catalogue of earthquakes and tsunami in the Indonesian region from 1538 to 1877 RON HARRIS1* & JONATHAN MAJOR1,2 1Department of Geological Sciences, Brigham Young University, Provo, UT 84602–4606, USA 2Present address: Bureau of Economic Geology, The University of Texas at Austin, Austin, TX 78758, USA *Corresponding author (e-mail: [email protected]) Abstract: The two volumes of Arthur Wichmann’s Die Erdbeben Des Indischen Archipels [The Earthquakes of the Indian Archipelago] (1918 and 1922) document 61 regional earthquakes and 36 tsunamis between 1538 and 1877 in the Indonesian region. The largest and best documented are the events of 1770 and 1859 in the Molucca Sea region, of 1629, 1774 and 1852 in the Banda Sea region, the 1820 event in Makassar, the 1857 event in Dili, Timor, the 1815 event in Bali and Lom- bok, the events of 1699, 1771, 1780, 1815, 1848 and 1852 in Java, and the events of 1797, 1818, 1833 and 1861 in Sumatra. Most of these events caused damage over a broad region, and are asso- ciated with years of temporal and spatial clustering of earthquakes. The earthquakes left many cit- ies in ‘rubble heaps’. Some events spawned tsunamis with run-up heights .15 m that swept many coastal villages away. 2004 marked the recurrence of some of these events in western Indonesia. However, there has not been a major shallow earthquake (M ≥ 8) in Java and eastern Indonesia for the past 160 years.
    [Show full text]
  • Visualization of the Geophysical Settings in the Philippine Sea Margins by Means of GMT and ISC Data
    Central European Journal of Geography and Sustainable Development 2020, Volume 2, Issue 1, Pages: 5-15 ISSN 2668-4322, ISSN-L 2668-4322 https://doi.org/10.47246/CEJGSD.2020.2.1.1 Visualization of the geophysical settings in the Philippine Sea margins by means of GMT and ISC data Polina Lemenkova* Ocean University of China, College of Marine Geo-sciences, 238 Songling Rd, Laoshan, 266100, Qingdao, Shandong, China; [email protected] Received: 22 February 2020; Revised: 12 March 2020; Accepted: 20 March 2020; Published online: 25 March 2020 _________________________________________________________________________________________________________________________ Abstract: The presented research aimed to perform geophysical modelling (gravity and geoid) and to evaluate the spatio-temporal variation of the marine geological data (distribution and depth of earthquakes) using combination of the Generic Mapping Tools (GMT) and available sources from the International Seismological Centre (ISC-EHB) that produce data on earthquakes as part of seismic survey and regional research projects. The target study area is a Philippine Sea basin (PSB) with two focused marginal areas: Philippine Trench and Mariana Trench, two hadal trenches located in the places of the tectonic plates subduction. Marine free-air gravity anomaly in the PSP shows higher values (>80 mGal) of the gravity fields structure at the volcanic areas and Philippine archipelago. Current study presented comparative geophysical analysis, and mapping free-air gravity and geoid in the Philippine Sea basin area. As a result of this study, the average level of earthquakes located in the Philippine Trench and Mariana Trench areas were compared, and those located in the Philippine archipelago are determined to be in the souther-western part (area of west Mindanao, south-west Visayas islands), while Luzon Islands shown shallower located earthquakes.
    [Show full text]
  • Philippine Sea Plate Inception, Evolution, and Consumption with Special Emphasis on the Early Stages of Izu-Bonin-Mariana Subduction Lallemand
    Progress in Earth and Planetary Science Philippine Sea Plate inception, evolution, and consumption with special emphasis on the early stages of Izu-Bonin-Mariana subduction Lallemand Lallemand Progress in Earth and Planetary Science (2016) 3:15 DOI 10.1186/s40645-016-0085-6 Lallemand Progress in Earth and Planetary Science (2016) 3:15 Progress in Earth and DOI 10.1186/s40645-016-0085-6 Planetary Science REVIEW Open Access Philippine Sea Plate inception, evolution, and consumption with special emphasis on the early stages of Izu-Bonin-Mariana subduction Serge Lallemand1,2 Abstract We compiled the most relevant data acquired throughout the Philippine Sea Plate (PSP) from the early expeditions to the most recent. We also analyzed the various explanatory models in light of this updated dataset. The following main conclusions are discussed in this study. (1) The Izanagi slab detachment beneath the East Asia margin around 60–55 Ma likely triggered the Oki-Daito plume occurrence, Mesozoic proto-PSP splitting, shortening and then failure across the paleo-transform boundary between the proto-PSP and the Pacific Plate, Izu-Bonin-Mariana subduction initiation and ultimately PSP inception. (2) The initial splitting phase of the composite proto-PSP under the plume influence at ∼54–48 Ma led to the formation of the long-lived West Philippine Basin and short-lived oceanic basins, part of whose crust has been ambiguously called “fore-arc basalts” (FABs). (3) Shortening across the paleo-transform boundary evolved into thrusting within the Pacific Plate at ∼52–50 Ma, allowing it to subduct beneath the newly formed PSP, which was composed of an alternance of thick Mesozoic terranes and thin oceanic lithosphere.
    [Show full text]
  • UNIVERSITY of CALIFORNIA, SAN DIEGO Marine Geophysical Study
    UNIVERSITY OF CALIFORNIA, SAN DIEGO Marine Geophysical Study of Cyclic Sedimentation and Shallow Sill Intrusion in the Floor of the Central Gulf of California A dissertation submitted in partial satisfaction of the requirements for the degree Doctor of Philosophy in Oceanography by Jared W. Kluesner Committee in Charge: Professor Peter Lonsdale, Chair Professor Paterno Castillo Professor Graham Kent Professor Falko Kuester Professor Michael Tryon Professor Edward Winterer 2011 Copyright Jared Kluesner, 2011 All rights reserved. The Dissertation of Jared W. Kluesner is approved, and it is acceptable in quality and in form for publication on microfilm and electronically: Chair University of California, San Diego 2011 iii To my parents, Tony and Donna Kluesner and my grandfather James Kluesner iv "...Let us go, we said, into the Sea of Cortez, realizing that we become forever a part of it" The Log from the Sea of Cortez John Steinbeck v TABLE OF CONTENTS Signature Page ...................................................................................... iii Dedication.............................................................................................. iv Epigraph ................................................................................................ v Table of Contents .................................................................................. vi List of Figures ........................................................................................ ix Acknowledgments ................................................................................
    [Show full text]
  • The 18.6Year Lunar Nodal Cycle and Surface Temperature Variability In
    JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 112, C02002, doi:10.1029/2006JC003671, 2007 The 18.6-year lunar nodal cycle and surface temperature variability in the northeast Pacific Stewart M. McKinnell1 and William R. Crawford2 Received 27 April 2006; revised 24 August 2006; accepted 21 September 2006; published 2 February 2007. [1] The 18.6-year lunar nodal cycle (LNC) is a significant feature of winter (January) air and sea temperatures along the North American west coast over a 400-year period. Yet much of the recent temperature variation can also be explained by wind patterns associated with the PNA teleconnection. At Sitka, Alaska, (57°N) and nearby stations in northern British Columbia, the January PNA index accounts for over 70% of average January air temperatures in lengthy meteorological records. It appears that the LNC signal in January air temperatures in this region is not independent of the PNA, but is a component of it. The Sitka air temperature record, along with SSTs along the British Columbia coast and the PNA index have significant cross-correlations with the LNC that appear at a 2-year lag, LNC leading. The influence of the PNA pattern declines in winter with decreasing latitude but the LNC component does not. It appears as a significant feature of long-term SST variation at Scripps Pier and the California Current System. The LNC also appears over centennial-scales in proxy temperatures along western North America. The linkage of LNC-moderated surface temperatures to processes involving basin-scale teleconnections expands the possibility that the proximate mechanism may be located remotely from its expression in the northeast Pacific.
    [Show full text]
  • Philippine Island Arc System Tectonic Features Inferred from Magnetic Data Analysis
    Terr. Atmos. Ocean. Sci., Vol. 26, No. 6, 679-686, December 2015 doi: 10.3319/TAO.2015.05.11.04(TC) Philippine Island Arc System Tectonic Features Inferred from Magnetic Data Analysis Wen-Bin Doo1, *, Shu-Kun Hsu1, 2, and Leo Armada 2 1 Center for Environmental Studies, National Central University, Taoyuan City, Taiwan, R.O.C. 2 Department of Earth Sciences, National Central University, Taoyuan City, Taiwan, R.O.C. Received 18 February 2013, revised 22 November 2013, accepted 11 May 2015 ABSTRACT Running along the middle of the Philippine archipelago from south to north, the Philippine fault zone is one of the world’s major strike-slip faults. Intense volcanism in the archipelago is attributed to the ongoing subduction along the trench systems surrounding it. This study interprets the magnetic data covering the Philippine fault zone and the bounding archi- pelago subduction systems to understand the structural characteristics of the study area. Magnetic data analysis suggests that the Philippine fault is roughly distributed along the boundary of high/low magnetization and separates the different amplitude features of the first order analytic signal. Visayas province is a specific area bounded by the other parts of the Philippine ar- chipelago. Further differentiating the tectonic units, the proto-Southeast Bohol Trench should be the main tectonic boundary between Visayas and Mindanao. A clear NE - SW boundary separates Luzon from Visayas as shown by the variant depths to the top of the magnetic basement. This boundary could suggest the different tectonic characteristics of the two regions. Key words: Philippine fault, Philippine archipelago, Magnetic data, Tectonic Citation: Doo, W.
    [Show full text]
  • OCEAN SUBDUCTION Show That Hardly Any Commercial Enhancement Finney B, Gregory-Eaves I, Sweetman J, Douglas MSV Program Can Be Regarded As Clearly Successful
    1982 OCEAN SUBDUCTION show that hardly any commercial enhancement Finney B, Gregory-Eaves I, Sweetman J, Douglas MSV program can be regarded as clearly successful. and Smol JP (2000) Impacts of climatic change and Model simulations suggest, however, that stock- Rshing on PaciRc salmon over the past 300 years. enhancement may be possible if releases can be Science 290: 795}799. made that match closely the current ecological Giske J and Salvanes AGV (1999) A model for enhance- and environmental conditions. However, this ment potentials in open ecosystems. In: Howell BR, Moksness E and Svasand T (eds) Stock Enhancement requires improvements of assessment methods of and Sea Ranching. Blackwell Fishing, News Books. these factors beyond present knowledge. Marine Howell BR, Moksness E and Svasand T (1999) Stock systems tend to have strong nonlinear dynamics, Enhancement and Sea Ranching. Blackwell Fishing, and unless one is able to predict these dynamics News Books. over a relevant time horizon, release efforts are Kareiva P, Marvier M and McClure M (2000) Recovery not likely to increase the abundance of the target and management options for spring/summer chinnook population. salmon in the Columbia River basin. Science 290: 977}979. Mills D (1989) Ecology and Management of Atlantic See also Salmon. London: Chapman & Hall. Ricker WE (1981) Changes in the average size and Mariculture, Environmental, Economic and Social average age of PaciRc salmon. Canadian Journal of Impacts of. Salmonid Farming. Salmon Fisheries: Fisheries and Aquatic Science 38: 1636}1656. Atlantic; Paci\c. Salmonids. Salvanes AGV, Aksnes DL, FossaJH and Giske J (1995) Simulated carrying capacities of Rsh in Norwegian Further Reading fjords.
    [Show full text]
  • Java and Sumatra Segments of the Sunda Trench: Geomorphology and Geophysical Settings Analysed and Visualized by GMT Polina Lemenkova
    Java and Sumatra Segments of the Sunda Trench: Geomorphology and Geophysical Settings Analysed and Visualized by GMT Polina Lemenkova To cite this version: Polina Lemenkova. Java and Sumatra Segments of the Sunda Trench: Geomorphology and Geophys- ical Settings Analysed and Visualized by GMT. Glasnik Srpskog Geografskog Drustva, 2021, 100 (2), pp.1-23. 10.2298/GSGD2002001L. hal-03093633 HAL Id: hal-03093633 https://hal.archives-ouvertes.fr/hal-03093633 Submitted on 4 Jan 2021 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 ГЛАСНИК Српског географског друштва 100(2) 1 – 23 BULLETIN OF THE SERBIAN GEOGRAPHICAL SOCIETY 2020 ------------------------------------------------------------------------------ --------------------------------------- Original scientific paper UDC 551.4(267) https://doi.org/10.2298/GSGD2002001L Received: October 07, 2020 Corrected: November 27, 2020 Accepted: December 09, 2020 Polina Lemenkova1* * Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Department of Natural Disasters, Anthropogenic Hazards and Seismicity of the Earth, Laboratory of Regional Geophysics and Natural Disasters, Moscow, Russian Federation JAVA AND SUMATRA SEGMENTS OF THE SUNDA TRENCH: GEOMORPHOLOGY AND GEOPHYSICAL SETTINGS ANALYSED AND VISUALIZED BY GMT Abstract: The paper discusses the geomorphology of the Sunda Trench, an oceanic trench located in the eastern Indian Ocean along the Sumatra and Java Islands of the Indonesian archipelago.
    [Show full text]