DOCSLIB.ORG

Thermal Structure of the Costa Rica – Nicaragua Subduction Zone

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Thermal Structure of the Costa Rica – Nicaragua Subduction Zone Physics of the Earth and Planetary Interiors 149 (2005) 187–200 Thermal structure of the Costa Rica – Nicaragua subduction zone Simon M. Peacocka,∗, Peter E. van Kekenb, Stephen D. Hollowayc, Bradley R. Hackerd, Geoffrey A. Aberse, Robin L. Fergasona a Department of Geological Sciences, Box 871404, Arizona State University, Tempe, AZ85287-1404, USA b Department of Geological Sciences, University of Michigan, Ann Arbor, MI, USA c Department of Geological Sciences, University of Texas El Paso, El Paso, TX, USA d Department of Geological Sciences, University Calif. Santa Barbara, Santa Barbara, CA, USA e Department of Earth Sciences, Boston University, Boston, MA, USA Received 5 March 2004; received in revised form 2 July 2004; accepted 26 August 2004 Abstract We constructed four high-resolution, finite-element thermal models across the Nicaragua – Costa Rica subduction zone to predict the (i) thermal structure, (ii) metamorphic pressure (P)–temperature (T) paths followed by subducting lithosphere, and (iii) loci and types of slab dehydration reactions. These new models incorporate a temperature- and stress-dependent olivine rheology for the mantle–wedge that focuses hot asthenosphere into the tip of the mantle–wedge. At P = 3 GPa (100 km depth), predicted slab interface temperatures are ∼800 ◦C, about 170 ◦C warmer than temperatures predicted using an isoviscous mantle–wedge rheology. At the same pressure, predicted temperatures at the base of 7 km thick subducting oceanic crust range from 500 ◦C beneath SE Costa Rica to 400–440 ◦C beneath Nicaragua and NW Costa Rica. The high thermal gradients perpendicular to the slab interface permit partial melting of subducting sediments while the underlying oceanic crust dehydrates, consistent with recent geochemical studies of arc basalts. Hydrous eclogite is predicted to persist to ∼120 km depth beneath Nicaragua. This is slightly less than the ∼150 km depth extent of a dipping low-seismic-velocity wave guide which may reflect deeper persistence of metastable gabbro. Along-strike variations in the calculated thermal structure are relatively minor compared to variations in the distribution of Wadati-Benioff earthquakes and arc geochemistry, suggesting that regional variations in slab stresses, crustal thickness, incoming sediment load, and the distribution of hydrous minerals in the incoming lithosphere play important roles. © 2004 Elsevier B.V. All rights reserved. Keywords: Subduction; Thermal modelling; Metamorphism; Arc magmatism; Lithosphere 1. Introduction ∗ Corresponding author. Tel.: +1 480 965 3391; fax: +1 480 965 1093. Earthquakes and arc magmatism in subduction E-mail address: [email protected] (S.M. Peacock). zones are intimately related to the thermal structure 0031-9201/$ – see front matter © 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.pepi.2004.08.030 188 S.M. Peacock et al. / Physics of the Earth and Planetary Interiors 149 (2005) 187–200 of the subducting plate and overlying mantle–wedge. tured the Cocos – Caribbean plate interface. Deeper Rates of subduction are more rapid than rates of thermal earthquakes define a Wadati-Benioff zone that marks diffusion such that the cold core of subducting plates the subducting Cocos plate and extends to 250 km may be up to 1000 ◦C cooler than the surrounding man- depth beneath Nicaragua (Protti et al., 1995; Husen et tle. Variations in the subduction rate and the age of in- al., 2003). A 1500 km-long volcanic arc extends from coming oceanic lithosphere lead to considerable vari- southern Mexico to central Costa Rica, but there is no ations in the thermal structure of different subduction Holocene volcanism in southern Costa Rica (e.g., Carr zones. Rapid subduction of mature oceanic lithosphere et al., 1990; Leeman et al., 1994). (e.g., NE Japan, Izu-Bonin) results in subducting plates The Cocos plate formed at two different spreading that are ∼300 ◦C cooler than subduction zones charac- centers – the Cocos–Pacific spreading center (i.e., the terized by modest convergence and young incoming east pacific rise, EPR) and the Cocos–Nazca spreading lithosphere (e.g., SW Japan, Cascadia) (Peacock and center (CNS) (von Huene et al., 1995; Barckhausen Wang, 1999). Cooler subducting plates correlate with et al., 2001). Northwest of the Nicoya peninsula in deeper Wadati-Benioff seismicity and more vigorous NE Costa Rica, relatively smooth Cocos crust, created arc magmatism (e.g., Kirby et al., 1996; Peacock and at the rapid-spreading EPR, is being subducted. That Wang, 1999; Hacker et al., 2003b). sea floor is characterized by extensive trench-parallel The Central American subduction zone is character- grabens forming just seaward of the trench (Ranero et ized by rapid (70–90 mm/year) convergence of young al., 2003). Southeast of the Nicoya peninsula, relatively (15–25 Ma) oceanic lithosphere (Barckhausen et al., rough Cocos crust created at the slow-spreading CNS, 2001; DeMets, 2001). Temperatures within the sub- is being subducted. Abundant seamounts roughen the ducting Cocos plate should therefore lie between the crust here, and deform the forearc wedge where they cool (NE Japan) and warm (SW Japan) end-member collide (von Huene et al., 2000). The age of the Cocos subduction zones. In the Central American subduction plate at the Middle America trench decreases towards zone both the convergence rate and the age of the in- the southeast, from 24 Ma off Nicaragua to 15 Ma off coming lithosphere vary only slightly along-strike, but SE Costa Rica. there are dramatic along-strike changes in the depth of Offshore of southern Costa Rica, the NE-trending Wadati-Benioff seismicity (Protti et al., 1995), position Cocos Ridge represents the trace of the Galapagos hot of the volcanic front, and arc geochemistry (Carr et al., spot. The thickness of the Cocos crust increases to- 1990; Leeman et al., 1994; Herrstrom et al., 1995). The wards the southeast, from 5 to 7 km off Nicaragua to Costa Rica – Nicaragua segment of the Central Ameri- 12 km off SE Costa Rica on the flank of the Cocos Ridge can subduction zone is as a focus site for two National (von Huene et al., 2000) to 21 km along the thickest Science Foundation Margins initiatives: the Seismo- part of the Cocos Ridge off SE Costa Rica (Walther et genic Zone Experiment (SEIZE) and the Subduction al., 2000). Subduction of this aseismic ridge coincides Factory. with the abrupt shallowing of slab seismicity and SE cessation of volcanism. Conductive cooling calculations predict that the heat 2. Geotectonic setting flow through the surface of 15–25 Ma oceanic litho- sphere should be 100–130 mW/m2. The sea floor gen- The Cocos plate subducts northeastward beneath erated at the EPR shows anomalously low values of the Caribbean plate along the Middle America trench 20–40 mW/m2, while that generated at the CNS gen- (Fig. 1). The convergence rate between the Cocos erates 105–115 mW/m2 (Fisher et al., 2003). Off the and Caribbean plates increases to the southeast, from Nicoya peninsula, Langseth and Silver (1996) mea- ∼60 mm/year off southern Guatamala to ∼90 mm/year sured heat flow values of 12 mW/m2 outboard of the off southern Costa Rica (DeMets, 2001). Convergence trench and 17 mW/m2 on the trench floor. These ex- is oblique, partitioned such that the forearc translates to ceptionally low heat flow values are best explained the northwest at 10–15 mm/year (DeMets, 2001; Nor- by vigorous hydrothermal circulation in the upper- abuena et al., submitted for publication). Along this most crust (Langseth and Silver, 1996; Fisher et al., margin, large subduction-thrust earthquakes have rup- 2003). S.M. Peacock et al. / Physics of the Earth and Planetary Interiors 149 (2005) 187–200 189 Fig. 1. Geotectonic map of Central America showing location of four transects for which thermal models were constructed. A–A, Nicaragua transect; B–B, NW Costa Rica transect; C–C, Central Costa Rica transect; D–D, SE Costa Rica transect. Solid triangles: Holocene volcanoes; thin lines: depth to Wadati-Benioff seismicity (Protti et al., 1995); QSC, Quesada sharp contortion (Protti et al., 1995). ODP 170, Oceanic Drilling Program Leg 170 drill sites 1039–1043. The Costa Rica – Nicaragua subduction zone is a cate that no frontal accretion has occurred for at least non-accreting margin characterized by a very small the past 3–4 million years (Morris et al., 2002). frontal prism and subduction erosion (von Huene and Wadati-Benioff zone seismicity defines a complex Scholl, 1991; Ranero and von Huene, 2000; von Huene geometry for the subducting Cocos plate. Fig. 2 shows et al., 2000). Off the Nicoya peninsula, analysis of seismicity from within 25 km on either side of the pro- ODP sites 1040 and 1043 reveals that all 400 m of ma- files A–A through D–D from Fig. 1. The seismicity rine sediments on the incoming Cocos plate are being is based on regional observations from deployments in subducted beneath the toe of the frontal prism (Silver, Costa Rica (Protti et al., 1995; Newman et al., 2002; 2000; Kimura et al., 1997). Uniformly low 10Be con- DeShon et al., 2003) and the EHB teleseismic cata- centrations in prism sediments at ODP site 1040 indi- logue (Engdahl et al., 1998). The solid lines indicate 190 S.M. Peacock et al. / Physics of the Earth and Planetary Interiors 149 (2005) 187–200 Fig. 2. Seismicity (symbols) and inferred slab surface geometry (solid lines). We plot events larger than magnitude 2.5 from up to 25 km away from the each profile. Seismicity is based on the EHB teleseismic catalogue (blue circles) and three regional experiments (Protti et al., 1995; Newman et al., 2002; DeShon et al., 2003). Geometry of the slab surface at depths less than 50 km is also based on reflection/refraction studies (e.g., Salleres´ et al., 2001).
Load more

Recommended publications
  • Of Moderate Earthquakes Along the Mexican Seismic Zone Geofísica Internacional, Vol
    Geofísica Internacional ISSN: 0016-7169 [email protected] Universidad Nacional Autónoma de México México Zobin, Vyacheslav M. Distribution of (mb - Ms) of moderate earthquakes along the Mexican seismic zone Geofísica Internacional, vol. 38, núm. 1, january-march, 1999, pp. 43-48 Universidad Nacional Autónoma de México Distrito Federal, México Available in: http://www.redalyc.org/articulo.oa?id=56838105 How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative Geofísica Internacional (1999), Vol. 38, Num. 1, pp. 43-48 Distribution of (mb - Ms) of moderate earthquakes along the Mexican seismic zone Vyacheslav M. Zobin Observatorio Vulcanológico, Universidad de Colima, 28045 Colima, Col., México. Received: August 26, 1996; accepted: August 3, 1998. RESUMEN Se estudia la distribución espacial de los valores mb-Ms para 55 sismos en el periodo de 1978 a 1994, con profundidades focales de 0 a 80 km, mb de 4.5 a 5.5, ocurridos a lo largo de la Trinchera Mesoamericana entre 95° y 107°W. Los valores mb-Ms tienen una distribución bimodal, con picos en 0.3 y 0.8 y mínimo en mb-Ms=0.6. Los eventos del primer grupo, con mb-Ms<0.6, se distribuyeron a lo largo de la trinchera en toda la región, comprendida por los bloques Michoacán, Guerrero y Oaxaca; la mayoría de los eventos del segundo grupo, con mb-Ms≥0.6, se encontraron en la parte central de la región en el bloque de Guerrero.
    [Show full text]
  • The Silent Earthquake of 2002 in the Guerrero Seismic Gap, Mexico
    The silent earthquake of 2002 in the Guerrero seismic gap, Mexico (Mw=7.6): inversion of slip on the plate interface and some implications (Submitted to Earth and Planetary Science Letters) A. Iglesiasa, S.K. Singha, A. R. Lowryb, M. Santoyoa, V. Kostoglodova, K. M. Larsonc, S.I. Franco-Sáncheza and T. Mikumoa a Instituto de Geofísica, Universidad Nacional Autónoma de México, México, D.F., México b Department of Physics, University of Colorado, Boulder, Colorado, USA c Department of Aerospace Engineering Science, University of Colorado, Boulder, Colorado, USA Abstract. We invert GPS position data to map the slip on the plate interface during an aseismic, slow-slip event, which occurred in 2002 in the Guerrero seismic gap of the Mexican subduction zone, lasted for ∼4 months, and was detected by 7 continuous GPS receivers located over an area of ∼550x250 km2. Our best model, under physically reasonable constraints, shows that the slow slip occurred on the transition zone at a distance range of 100 to 170 km from the trench. The average slip was about 22.5 cm 27 (M0∼2.97 x10 dyne-cm, Mw=7.6). This model implies an increased shear stress at the bottom of the locked, seismogenic part of the interface which lies updip from the transition zone, and, hence, an enhanced seismic hazard. The results from other similar subduction zones also favor this model. However, we cannot rule out an alternative model that requires slow slip to invade the seismogenic zone as well. A definitive answer to this critical issue would require more GPS stations and long-term monitoring.
    [Show full text]
  • 1. Introduction1
    Kimura, G., Silver, E.A., Blum, P., et al., 1997 Proceedings of the Ocean Drilling Program, Initial Reports, Vol. 170 1. INTRODUCTION1 Shipboard Scientific Party2 The planet is profoundly affected by the distributions and rates of al., 1990), which extends from the Caribbean coast of Colombia to materials that enter subduction zones. The material that is accreted to Limon, Costa Rica. In Costa Rica, the boundary consists of a diffuse the upper plate results in growth of the continental mass, and fluids left lateral shear zone from Limon to the Middle America Trench squeezed out of this accreted mass have significance for biologic and (Ponce and Case, 1987; Jacob and Pacheco, 1991; Guendel and geochemical processes occurring on the margins. Material that is not Pacheco, 1992; Goes et al., 1993; Fan et al., 1993; Marshall et al., accreted or underplated to the margin bypasses surface residency and 1993; Fisher et al., 1994; Protti and Schwartz, 1994). The north- descends into the mantle, chemically affecting both the mantle and trending boundary between the Cocos and Nazca Plates is the right- magmas generated therefrom. Subduction of the igneous ocean crust lateral Panama fracture zone. West of this fracture zone is the Cocos returns rocks to the mantle that earlier had been fractionated from it Ridge, a trace of the Galapagos Hotspot, which subducts beneath the in spreading centers, along with products of chemical alteration that Costa Rican segment of the Panama Block. occur on the seafloor. Sediments that are subducted include biogenic, The Nicoya Peninsula is composed of Late Jurassic to Late Creta- volcanogenic, authigenic, and terrigenous debris.
    [Show full text]
  • The Caribbean-North America-Cocos Triple Junction and the Dynamics of the Polochic-Motagua Fault Systems
    The Caribbean-North America-Cocos Triple Junction and the dynamics of the Polochic-Motagua fault systems: Pull-up and zipper models Christine Authemayou, Gilles Brocard, C. Teyssier, T. Simon-Labric, A. Guttierrez, E. N. Chiquin, S. Moran To cite this version: Christine Authemayou, Gilles Brocard, C. Teyssier, T. Simon-Labric, A. Guttierrez, et al.. The Caribbean-North America-Cocos Triple Junction and the dynamics of the Polochic-Motagua fault systems: Pull-up and zipper models. Tectonics, American Geophysical Union (AGU), 2011, 30, pp.TC3010. 10.1029/2010TC002814. insu-00609533 HAL Id: insu-00609533 https://hal-insu.archives-ouvertes.fr/insu-00609533 Submitted on 19 Jan 2012 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. TECTONICS, VOL. 30, TC3010, doi:10.1029/2010TC002814, 2011 The Caribbean–North America–Cocos Triple Junction and the dynamics of the Polochic–Motagua fault systems: Pull‐up and zipper models C. Authemayou,1,2 G. Brocard,1,3 C. Teyssier,1,4 T. Simon‐Labric,1,5 A. Guttiérrez,6 E. N. Chiquín,6 and S. Morán6 Received 13 October 2010; revised 4 March 2011; accepted 28 March 2011; published 25 June 2011.
    [Show full text]
  • SIO and NEL Exploration of the Middle America Trench B. Index
    A. Index map: S.I.O. and N.E. L. exploration of the Middle America Trench B. Index map: Sounding lines furnished by the U.S. Hydrographic OfKce ECHO-SOUNDING LINES USED IN THE PREPARATION OF PLATES 2, 3, AND 6 FISHER, PLATE 1 Geological Society of America, volume 72 Downloaded from http://pubs.geoscienceworld.org/gsa/gsabulletin/article-pdf/72/5/703/3442060/i0016-7606-72-5-703.pdf by guest on 02 October 2021 ROBERT L. FISHER Scripps Institution of Oceanography, University of California, La Jolla, Calif. Middle America Trench: Topography and Structure Abstract: From 1952 to 1959, during nine expedi- companying paper (Shor and Fisher, 1961) were tions of the Scripps Institution of Oceanography employed in determining the trench structure. and one of the U. S. Navy Electronics Laboratory, Three refraction stations were taken along the axis research vessels recorded 31,950 miles of echo- of the trench west of Acapulco and two along its sounding traverses in and adjacent to the Middle axis off Guatemala and El Salvador. Another sta- America Trench, which extends from the Islas Tres tion was shot on the shelf and one 60 miles sea- Marias off western Mexico to the Cocos Ridge ward of the trench off Guatemala. Thick sediments southwest of Costa Rica. were found in the Tres Marias Basin off Manzanillo The Middle America Trench is continuous at and at the shelf station off Guatemala. Arrivals depths greater than 2400 fathoms (4400 m) for 1260 from rock with compressional wave velocity of 4-6 miles, except off Manzanillo and Zihuatanejo, km/sec were observed at the Tres Marias Basin and Mexico, where submarine mountains lie in the Guatemala shelf stations.
    [Show full text]
  • Geology of Honduran Geothermal Sites
    Caribbean Basin Proyecto Geology of Honduran Geothermal Sites by Dean B. Eppler ince March 1985 a team of Labora- The geology of Central America is ex- meters apart. Most of these are normal tory geologists has been working tremely complex. The meeting of three faults, developed as a result of stress that is with counterparts from the Empresa tectonic plates in western Guatemala and literally pulling the country apart along an Nacionals de Energia E1ectrica (ENEE) of southern Mexico has resulted in an un- east-west axis. Although Honduras has Honduras and from four American in- usual juxtaposition of structures and rock been spared the devastating earthquakes stitutions on a project to locate, evaluate, types whose geologic history has yet to be that have rocked much of Central and develop geothermal resources in Hon- unraveled. Textbook reconstructions of America, we suspect that deformation is duras. The team, headed by Grant Heiken tectonic-plate motions very often sidestep taking place continually; in some areas and funded by the U.S. Agency for Inter- the problem of how Central America de- faults cut stream gravels that are only sev- national Development, has so far com- veloped through geologic time by never eral thousand years old. The result of this pleted three trips to Central America to showing its existence until the present faulting, as shown in the accompanying study in detail the geology of six geo- time. photo, is rugged topography dominated by thermal spring sites. As shown on the accompanying map, north-south oriented fault basins and adja- Honduras lies on a portion of the Carib- cent fault-block mountains very similar to Basic Geology of Honduras bean tectonic plate called the Chortis those found in the Basin and Range Block.
    [Show full text]
  • Deep Sea Drilling Project Initial Reports Volume 67
    36. STRATIGRAPHY AND STRUCTURES OF THE MIDDLE AMERICA TRENCH: DEEP SEA DRILLING PROJECT LEG 67 TRANSECT OFF GUATEMALA1 William T. Coulbourn, Geological Research Division, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California ABSTRACT The eight holes drilled at Sites 499 and 500 in the axis of the Middle America Trench are the first to recover the com- plete sedimentary section of an active trench. These holes demonstrate extension of the subducting Cocos Plate and its sedimentary overburden, even at the edge of the Guatemalan margin. A depression within the turbidites filling the Trench is probably a result of warping of those beds by differential movements of the underlying structures, and not the result of erosion by turbidity flows along the bottom of the Trench. Patterns of reflectors on seismic profiles match the well-derived cross section but taken alone would not reveal the wealth of detail and perhaps not even the major struc- tures underlying the turbidite fill. Drilling and geophysical data at Sites 499 and 500 suggest that rather than becoming incorporated into the lowermost Guatemalan margin, axial turbidites are passively buried beneath slope sediments. INTRODUCTION is the product of convergence of the Cocos and Carib- bean plates. The combination of outer swell, offsets, During Leg 67 of the Deep Sea Drilling Project eight and earthquake focal mechanisms for world subduction holes were drilled in the axis of the Middle America zones has led to the concept that the subducting plate Trench seaward of the coast of Guatemala (Fig. 1). This behaves as an elastic beam with a load applied at one sampling pattern was not planned prior to sailing, but end (Isacks et al., 1968; Hanks, 1971; Caldwell et al., because the recovery of clathrates forced reassessment 1976).
    [Show full text]
  • Deep Sea Drilling Project Initial Reports Volume 66
    11. PETROLOGY OF MIDDLE AMERICA TRENCH AND TRENCH SLOPE SANDS, GUERRERO MARGIN, MEXICO1 Steven B. Bachman, Department of Geological Sciences, Cornell University, Ithaca, New York and Jeremy K. Leggett, Department of Geology, Imperial College, London, United Kingdom INTRODUCTION son and Suczek (1979). The monocrystalline quartz has both undulatory (>5° extinction) and nonundulatory The sandstone petrology of Leg 66 samples provides extinction in different grains. Subgrain boundaries are insights into changes through time in the geology of the developed in some grains. There is a large variety of source regions along the Guerrero portion of the Middle poly crystalline quartz types; most samples have about America continental margin. This in turn constrains equal percentages of finely crystalline (>5 crystals/ possible models of the evolution of the Middle America grain) and coarsely crystalline (<5 crystals/grain) Trench (e.g., de Czerna, 1971; Malfait and Dinkleman, grains. Many of the finely crystalline quartz grains ap- 1972; Karig, 1974). Primarily medium-grained sands pear to be derived from rocks with a strain and/or meta- and sandstones, representing the widest variety avail- morphic history: polyganized, bimodal (partial recrys- able of trench/trench slope settings and ages, were tallization of the larger set of grains), and tectonite analyzed in both light and heavy mineral studies. Stan- (highly oriented crystals with elongate boundaries) types dard techniques were used as much as possible in order predominate. Plagioclase and potassium feldspar occur to compare results from other margins and from ancient in near equal percentages (Qm-P-K plot, Fig. 1). Micro- rocks. cline is a common accessory in all the samples but is the predominate potassium feldspar in samples in the lower LIGHT MINERALS 100 meters of Site 493 on the upper slope.
    [Show full text]
  • Geophysical Modelling of the Middle America Trench Using Gmt
    Annals of Valahia University of Targoviste. Geographical Series (2019), 19(2): 73-94 DOI: 10.2478/avutgs-2019-0008 ISSN (Print): 2393-1485, ISSN (Online): 2393-1493 © Copyright by Department of Geography. Valahia University of Targoviste GEOPHYSICAL MODELLING OF THE MIDDLE AMERICA TRENCH USING GMT Polina LEMENKOVA Ocean University of China, College of Marine Geo-sciences. 238 Songling Rd. Laoshan, 266100, Qingdao, Shandong, PRC. Tel.: +86-1768-554-1605. email: [email protected] Abstract The study is focused on the geomorphological analysis of the Guatemala Trench, East Pacific Ocean. Research goal is to find geometric variations in western and eastern flanks of the trench and correlation of the submarine geomorphology with geologic settings and seismicity through numerical and graphical modelling. Methods include GMT based analysis of the bathymetry, geomorphic shape and surface trends in topography and gravity grids. Dataset contains raster grids on bathymetry, gravity, geoid and geological layers. Technical workflow is following: 1) Bathymetric mapping by modules ('grdcut', 'grdimage'); 2) Datasets visualizing and analysis, 3) Topographic and gravimetric surface modelling by ASCII data; 4) Cartographic mapping ('psbasemap', 'psxy', 'grdcontour') 4) 3D-mesh modelling; 5) Automatically digitized orthogonal cross-stacked profiles (‘grdtrack’); 6) Visualizing curvature trends (‘trend1d’); 7) statistical histograms. Results reveal unevenness in the structure of the submarine landforms. Modelling cross-section profiles highlighted depth variation at different parts of the transects and seafloor segments. Geomorphic structure has straight shape form of the slopes with steep oceanward forearc. Its geometry has steep and strait shape which correlates with seismicity. Depth samples vary: -3000 to -6200 m, seafloor is 3-5 km wide.
    [Show full text]
  • Lafemina, P. C., T. H. Dixon, W. Strauch, Bookshelf Faulting In
    Downloaded from geology.gsapubs.org on June 3, 2010 Geology Bookshelf faulting in Nicaragua Peter C. La Femina, T.H. Dixon and W. Strauch Geology 2002;30;751-754 doi: 10.1130/0091-7613(2002)030<0751:BFIN>2.0.CO;2 Email alerting services click www.gsapubs.org/cgi/alerts to receive free e-mail alerts when new articles cite this article Subscribe click www.gsapubs.org/subscriptions/ to subscribe to Geology Permission request click http://www.geosociety.org/pubs/copyrt.htm#gsa to contact GSA Copyright not claimed on content prepared wholly by U.S. government employees within scope of their employment. Individual scientists are hereby granted permission, without fees or further requests to GSA, to use a single figure, a single table, and/or a brief paragraph of text in subsequent works and to make unlimited copies of items in GSA's journals for noncommercial use in classrooms to further education and science. This file may not be posted to any Web site, but authors may post the abstracts only of their articles on their own or their organization's Web site providing the posting includes a reference to the article's full citation. GSA provides this and other forums for the presentation of diverse opinions and positions by scientists worldwide, regardless of their race, citizenship, gender, religion, or political viewpoint. Opinions presented in this publication do not reflect official positions of the Society. Notes Geological Society of America Downloaded from geology.gsapubs.org on June 3, 2010 Bookshelf faulting in Nicaragua Peter C. La Femina T.H.
    [Show full text]
  • General Disclaimer One Or More of the Following Statements May Affect
    General Disclaimer One or more of the Following Statements may affect this Document This document has been reproduced from the best copy furnished by the organizational source. It is being released in the interest of making available as much information as possible. This document may contain data, which exceeds the sheet parameters. It was furnished in this condition by the organizational source and is the best copy available. This document may contain tone-on-tone or color graphs, charts and/or pictures, which have been reproduced in black and white. This document is paginated as submitted by the original source. Portions of this document are not fully legible due to the historical nature of some of the material. However, it is the best reproduction available from the original submission. Produced by the NASA Center for Aerospace Information (CASI) TECTONIC LINEAMENTS IN THE CENOZOIC VOLCANICS Or" SOUTHERN GUATEMALA: EVIDENCE FOR A BROAD CONTINENTAL PLATE BOUNDARY ZONE (NASA-Ch-17545b) ZICTCNIC llbkAhINTS IN Tb! tiE5-15499 CYNUZOIC YGLCAHICZ GF SGUTfkFK GU172rAli: XvIDENCB FCB a EfCAL CCN11t 1611L FLAIR LCUNLARY 20ht (JEt Frcpulsicr Lab.) 23 F Unclas HC 11021LIF A01 -SCL C8b G3/43 14306 k/ M. Baltuck Department Geology '^ _i ^ Q1a, J^O Tulane University ► New Orleans, LA 70118 T. H. Dixon Jet Prcpulsion Laboratory Mail Code 183-701 4800 Oak Grove Drive Pasadena, CA 91109 Submitted to Geology K October, 1984 This report was prepared for the Jet Pripulsior Laboratory, California Institute of Technology, ,nonsored by the 'National Aeronautics and Space Administration. ABSTRACT The northern Caribbean plate boundary has been undergoing left-lateral strike slip motion since middle Tertiary time.
    [Show full text]
  • The New Central American Seismic Hazard Zonation: Mutual Consensus Based on up to Day Seismotectonic Framework
    See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/320482106 The new Central American seismic hazard zonation: Mutual consensus based on up to day seismotectonic framework Article in Tectonophysics · October 2017 DOI: 10.1016/j.tecto.2017.10.013 CITATIONS READS 3 649 11 authors, including: Belén Benito Alejandra Staller Universidad Politécnica de Madrid Universidad Politécnica de Madrid 131 PUBLICATIONS 828 CITATIONS 28 PUBLICATIONS 61 CITATIONS SEE PROFILE SEE PROFILE Alvaro Climent Eduardo Camacho Instituto Costarricense de Electricidad Universidad de Panamá, Panamá, Panamá 11 PUBLICATIONS 118 CITATIONS 35 PUBLICATIONS 152 CITATIONS SEE PROFILE SEE PROFILE Some of the authors of this publication are also working on these related projects: SISMOCAES. Estudios geológicos y sísmicos en Centroamérica y lecciones hacia la evaluación del riesgo sísmico en el Sur de España. View project Estudio de riesgo sísmico para la ejecución del proyecto la ruta nacional no. 39 zona de San José (Costa Rica) View project All content following this page was uploaded by Alejandra Staller on 18 April 2018. The user has requested enhancement of the downloaded file. Tectonophysics xxx (2017) xxx-xxx Contents lists available at ScienceDirect Tectonophysics journal homepage: www.elsevier.com The new Central American seismic hazard zonation: Mutual consensus based on up to day seismotectonic framework Guillermo E. Alvaradoa⁠ , Belén Benitob⁠ ,⁠⁠ ⁎⁠ , Alejandra Stallerb⁠ ,⁠ ⁎⁠ , Álvaro Climenta⁠ , Eduardo
    [Show full text]