I cover many earth extremities ranging from Earthquakes, Quake Swarms, Volcanic Activity/Eruptions, CME's Coronal Mass Ejections, Solar Flares, Geomagnetic Storms, Magnetosphere Pressure plus other solar related radiation pulses, Asteroid/Meteorite Threats, Solar System Threats, Landslides, Flooding, Sink Holes, Hurricanes, Typhoons, Storms, Tsunami's, prolonged Snowfall/Ice, Heatwaves, Drought, Nuclear Fallout/Leak, Viruses, Deceases, Epidemics, Dead Mammals/Birds/Animals, Pollution Threat Levels and many more events. You can help Wikipedia by expanding it. The Eltanin Fault System(Eltanin Fracture Zone) is a series of six or seven dextral transform faults that offset the Pacific-Antarctic Ridge, a spreading zone between the Pacific Plateand the Antarctic Plate. Four segments of the Tharp transform (Fig. Unless the presence of short spreading centres is taken into account, the application of simple plate cooling models using the entire length of transforms leads to underestimates of temperature and plate coupling. Four of them have T-axes nearly perpendicular to those transforms while the smallest of Mw 5.3 in 1982 is oriented about 45 to the Tharp. Eltanin Fracture Zone System is located in the Undersea Features Area of the Country of Undersea Features. (2010) that describes the relative motion of the Pacific and Antarctic plates. 'dextrally' (also known as right-laterally) which means if you D.F. Approximate slopes are denoted by dashed lines. [] ( ) "eltanin fracture zone" in Chinese : "eltanin" in Chinese : "fracture zone" in Chinese : ; ; ; ; ; . The fault segment between -665 and -680 km (green symbols in Fig. Mw is systematically higher than mb for strike-slip events along the three transforms, on average about 0.5 units. Observations of the Antarctic Circumpolar Current Over the Udintsev The earthquakes were analysed using the standard Global CMT (GCMT) algorithm as described in Dziewonski et al. Mammericks This partitioning of slip likely results from changes during the last few million years in the Euler pole for relative motion between the Antarctic and Pacific plates. The precision of epicentral locations in his study was improved considerably by using data from new seismic stations in Antarctica that were installed during the International Geophysical Year, 1957-1958, and computer programs for analysing P and PKP arrival times. Undersea Features Fishing & Outdoor Fracture Zone Maps: Undersea Features is home to a total of 187 Fracture Zone(s), listed below. Figs 5 and 6 show five other normal-faulting mechanisms adjacent to but not on the Tharp and Hollister transforms. The Eltanin Fault System (Eltanin Fracture Zone) is a series of six or seven dextral transform faults that offset the Pacific-Antarctic Ridge, a spreading zone between the Pacific Plate and the Antarctic Plate. Gregg P.M. Ekstram This is a consequence of the continuity of displacement eigenfunctions for surface waves across discontinuities, and the dependence of the excitation on these displacements. McGuire Their average repeat time is 7.1 yr and their COV is 0.28. VanDeMark (2006) analysed the relative locations of earthquakes of moderate magnitude along oceanic transform faults with a double-difference method using Rayleigh waves of periods between 30 and 80 s. He used 92 events along the Eltanin transform faults from 1980 to early 2006, about half of the number we analysed. It moves Listen to the audio pronunciation of Eltanin Fracture Zone on pronouncekiwi 7, however, since it is located just to the east of other large shocks along the Heezen transform. The inversion procedure follows the method of Ekstrm (1989) and leads to estimates of the earthquake focal mechanism, source-time function and point-source depth that are consistent with both the P-wave data and the CMT results. The Eltanin Transform Fault and Fracture Zone is a series of six or seven dextral transform faults along ~800 km of the Pacific-Antarctic Ridge that offset it ~1600 km. It and some other segments of the three Eltanin transforms appear to be well coupled seismically. The slope of -1.0 for the latter period for Mw 5.4-6.0 is typical of that for earthquakes in many areas of the world. Those estimates are smaller than those for oceanic transforms at much slower moving plate boundaries, which is in accord with the notion, which we accept, that temperatures are higher at a given depth for fast moving plate boundaries. . We assume that earthquakes along a given segment of a transform occur on single faults although the distribution of CMT solutions scatters about 15 km perpendicular to the transforms. It is that region where three of the four normal faulting earthquakes in Fig. Seabeam and SeaMARC II swath-mapping surveys, with ancillary magnetic and gravity profiling, describe the fast-slipping (84-86 mm year1) 380 km-long Heezen transform (56 S) and the 145 km-long Raitt transform (54 S), together with the youngest parts of their rise-flank fracture zones. Smith The flow of NADW through the Romanche and Chain Fracture Zones may serve as a conduit for larval transport from the western North Atlantic to the eastern South Atlantic. Search for: Recent Posts. Behn The Eltanin Fault System (Eltanin Fracture Zone) is a series of six or seven dextral transform faults that offset the Pacific-Antarctic Ridge, a spreading zone between the Pacific Plate and the Antarctic Plate.The affected zone of the Pacific-Antarctic Ridge is about 800 km long, between 56 S, 145 W and 54.5 S, 118.5 W, southwest of Easter Island, and about as far as one can get from . J. Structural geomorphology of the eltanin fault system and adjacent Bar at upper right on map shows water depths in metres. Specifically, in the study of the Eltanin earthquakes, we have obtained depths ranging from the shallowest used in the CMT algorithm (12 km) to 26 km. We propose that the remainder of the plate motion . We then examine other segments with fewer but larger earthquakes. The synthetic waveforms used in the CMT inversion are corrected for lateral heterogeneity using the whole-mantle model of Dziewonski & Woodward (1992) for the body waves and long-period mantle waves, and the phase-velocity maps of Ekstrm et al. Fracture zone evolution is investigated using dynamic models that allow the fault zones to freely slip. Figs 4-6 depict the three Eltanin transforms in greater detail. Clearly, a gradient in the maximum size of earthquakes and seismic coupling occurs between the eastern and western ends of the Heezen transform. Dziewonski a generally flat zone extending from the shore to the shelf break continental margin shallow-water areas close to continent abyssal plain flat depositional surfaces that cover extensive portions of the deep-ocean basins The method that used most frequently to investigate sediment and rock layers of the sea floor is: We find that one isolated asperity along the Heezen transform ruptures about every 4.0 1.0 yr. M.D. J. Seamount chains in the Pacific basin tend to be aligned northwesterly, and several chains are intimately associated with fracture zones; the Eltanin Fracture Zone in the southwestern Pacific is an example. Montesi The transform valley is 15-20 km wide and 2-4 km deep. How are fracture zones like the Eltanin created? [2], The trench has a depth of 7,761m (25,463ft), is 300km (190mi) long and has an average width of 19km (12mi) and allows for a major circulation of deep ocean basin water from the west Atlantic to the east Atlantic basins. A Seabeam reconnaissance of the 400 km-long fast-slipping (88 mm yr-1) Heezen transform fault zone and the 55 km-long spreading center that links it to Tharp transform defined and bathymetrically described several types of ridges built by tectonic uplift and volcanic construction. Properties of oceanic lithosphere: Revised plate cooling model 3391km (2107mi) WSW of Ushuaia, Argentina 5) are characterized by shocks of Mw= 5.9 but about half of its length is not. H.W. We note that our revised catalogue with its additions of more solutions, especially of Mw 5.5-6.0, is more complete than the existing CMT catalogue. Tectonic and magmatic ridges in the eltanin fault system - SpringerLink Extending the work of Stewart & Okal (1983), they again emphasized the dominance of aseismic slip. Earthquakes of Mw > 5.55 were included in each computation. The Romanche Trench, also called the Romanche Furrow or Romanche Gap, is the third deepest of the major trenches of the Atlantic Ocean, after the Puerto Rico Trench and the South Sandwich Trench. Solomon It is the only example of a very short time interval between large shocks along segments of the Eltanin transforms. Wolfe et al. where is and what is eltanin transform fault and fracture. If those segments are not fully coupled, our calculations of downdip width, of course, are minimum estimates. They concluded from analyses of seismograms, however, that the transform earthquakes themselves did not have a significant component of slow seismic slip. Ships have surveyed the active parts of three Eltanin transforms infrequently since they straddle the pole of inaccessibility' at the farthest point on the Earth from inhabited land (Lonsdale 1994). Aseismic parts of the Heezen and Tharp fracture zones can be traced far to the northwest and . The Eltanin Fault System (Eltanin Fracture Zone) is a series of six or seven dextral transform faults that offset the Pacific-Antarctic Ridge, a spreading zone between the Pacific Plate and the Antarctic Plate. The excitation of the long-period waveforms used in the CMT analysis does not vary rapidly as a function of source depth for shallow-focus earthquakes. Mw determined in this study compared with the surface wave magnitude Ms as computed by either ISC or PDE for periods between about 17 and 22 s. Mw is determined at longer periods. When Sykes showed his results to M. Ewing, the latter arranged with NSF (US National Science Foundation) for the Research Vessel Eltanin to map the region. CHALLENGER FRACTURE ZONE. . . Ekstram We did not use the ISC catalogue for events after 1999. Systematic deviations can occur when the Earth structure in the source area deviates significantly from the structure assumed in the calculation of synthetic seismograms, that is, from PREM (Dziewonski & Anderson 1981). He concluded that a major fracture zone intersected the mid-oceanic ridge at that location, much like those mapped by Menard (1960) farther north. Wolfe et al. . LOUISVILLE RIDGE AND ELTANIN FRACTURE ZONE 3053 west to isolated peaks superimposed on ridge segments in the southeast. We have combined shipboard and Seasat altimeter derived data in an intergrated geological and geophysical study of the Louisville Ridge; a 3500kmlong seamount chain extending from the Tonga trench to the Eltanin Fracture Zone.