Reply. Observed trends in the geoid slope versus age plots are similar on both branches of the Eltanin and the east limb of the Udintsev fracture zone. Because of its remoteness, the Pacific-Antarctic ridge (PAR) south of the Udintsev fracture zone (FZ) remained poorly known until the . 21 Badges. Journal of Geophysical Research: Oceans 2019-07-04 | Journal article DOI: 10.1029/2019JC015024 Contributors . A two-dimensional FEM is used to investigate the flow driven by the horizontal temperature gradient at a fracture zone and to calculate the resulting geoid and topography anomalies. Because of its remoteness, the Pacific-Antarctic ridge (PAR) south of the Udint-sev fracture zone (FZ) remained poorly known until the recent past (1). May 20, 2015; Add bookmark Deep Sea Research Part II: Topical Studies in Oceanography 2016 . However, broad zones of complex deformation are ubiquitous at TFs. Abstract. Meander characteristics (left) at Macquarie Ridge and (right) over the Udintsev Fracture Zone. The U.S. Department of Energy's Office of Scientific and Technical Information These data were collected to better understand earthquake hazards in the Charleston seismic zone by imaging structural features in the crystalline basement and to image heavy mineral sands containing titanium, zirconium, and . An up-to-date map of the Antarctic Circumpolar Current (ACC) fronts is constructed from the latest version of mean dynamic topography from satellite altimetry (Park et al., 2019, Observations of the Antarctic Circumpolar Current over the Udintsev Fracture Zone, the narrowest choke point in the Southern Ocean, JGR-Oceans, in review). (JDFR), Blanco Fracture Zone (BFZ) and the Gorda Ridge . The similarity in trends argues against the effects of isolated thermal or bathymetric anomalies and appears instead to The "Park/Durand" fronts are a recent update on the locations of the fronts . 1.. IntroductionThe Hollister Ridge, recently discovered by satellite-derived marine gravity , is an aseismic ridge located on the western flank of the Pacific-Antarctic Ridge (PAR) axis, between the Eltanin and Udintsev Fracture Zones (FZ) ().It was sampled during the Pacantarctic cruise (N/O L'Atalante, 1996, ).Because of its particular position and shape, this structure has been the . Udintsev Fracture Zone (Orsi et al., 1995) Udintsev Fracture Zone - the narrowest pathway of the ACC . (HR), Udintsev Fracture Zone (UFZ), Tharp Fracture Zone (TFZ) and the . above the abyssal plains downstream of the Udintsev Fracture Zone (UFZ, 145W). Time-series as wiggles along a track. For instance, various fracture zones, such as the Ascension, Tasman, and Udintsev fracture zones, can be extended much closer to adjacent coninental margins. Here, we propose a new conceptual model for the progressive deformation within broad zones at oceanic TFs through detailed morphological, seismic, and stress analyses. Oceanic transform faults (TFs) are commonly viewed as single, narrow strike-slip seismic faults that offset two mid-ocean ridge segments. Lee and M.H. Computer-generated bathymetric map of a portion of the S-central Pacific, showing the Eltanin and Udintsev Fracture Zone systems, and the prominent seamount at about 53.9S, 140.3W in the epicentral area of the March 1991 swarm. Guest blog by Karen Assman. 1281-1284) Louis Gli, Henri Bougault, Daniel Aslanian, Anne Briais, Laure Dosso, Jol Etoubleau, Jean-Pierre Le Formal, Marcia Maia, Hlne Ondras, Jean-Louis Olivet, Chris Richardson, Keizo Sayanagi, Nobukazu Seama, Anjana Shah, Ivan Vlastelic and Michiko . }, author = {Y.H. immediately upstream, leading to an overall barotrop-ization of the ow in these regions. Values are averaged between the contours in (a). Udintsev Transform volcano. The "Park/Durand" fronts are a recent update on the locations of the fronts . Acoustic signals (T-waves) from a seismic swarm were detected in 1990 from a source along the Udintsev fracture zone at about 143 deg W, along the segment that corresponds with the Pacific-Antarctic Ridge (Global Volcanism Network Bulletin, 1990). Just down- stream of Drake Passage, arotmd 60W, they veer northward around the ridges of the Scotia Arc (Gordon et al., 1978; GiUe, 1994). On the Egyptian continental shelf, in the Mediterranean Sea, at approximately the midpoint between the two outlets of the Nile at Masabb Rashid and Masabb Dumyat. Journal of Geophysical Research: Oceans 2019-07-04 | Journal article DOI: 10.1029/2019JC015024 Contributors . . c. Meanders and vorticity balance From (2), the steady vorticity balance in the ocean Journal of Geophysical Research: Oceans . A. Shah, I. Vlastelic, and M. Yamamoto, 1997, Evolution of the Pacific-Antarctic Ridge South of the Udintsev Fracture . . A new regional climatology was obtained through the objective analysys of the data on neutral surfaces. SEMI-AUTOMATIC FRACTURE ZONE TRACKING 2468 f Geochemistry, Geophysics, Geosystems 10.1002/2015GC005853 Figure 6. is only 170 km wide in the Udintsev Fracture Zone, forming the narrowest circumpolar choke point First observations of highquality hydrography in the Udintsev Fracture Zone show no Antarctic bottom water colder than 0.2 C The Udintsev Fracture Zone is a suitable site for a longterm monitoring of the Antarctic Circumpolar Current Apr 23, 2003 1.188 94 Visit site. No deep fracture zone can be identified in existing Smith and Sandwell [1997] bathymetry, but a detailed . But we have left the Amundsen Sea. This bimodal axial rearrangement has propagated southward for the last 30 to 35 million years, leaving trails on the sea floor along a 1000-kilometer-long V-shaped structure south of the Udintsev fracture zone. New (NRL)Zealand, and through the Eltanin and Udintsev Fracture Zones influencein the central Pacific Ocean. Observations of the Antarctic Circumpolar Current Over the Udintsev Fracture Zone, the Narrowest Choke Point in the Southern Ocean. Next topic (10) A geographical bar graph plot. (b) Vertical profile of mean EKE (m 2 s 2; logarithmic scale) along the path of the meander. a 1000-kilometer-long V-shaped structure south of the Udintsev fracture zone. After leaving Gothenburg on 12 December in the snow, I spent a warm day exploring and eating my way through Singapore on the way to Christchurch, New Zealand and then a few days getting over the jetlag in New Zealand summer. Time-series as wiggles along a track. To the extent that oceanographic flows are strictly barotropic, they should be steered along contours of Sarah . a 1000-kilometer-long V-shaped structure south of the Udintsev fracture zone. 2. Just down-stream of Drake Passage, around 60W, they veer northward around the ridges of the Scotia Arc (Gordon et al., 1978; Gille, 1994). We have compared our results to geoid anomalies over the Udintsev fracture zone, and have found that the predicted geoid anomalies, with high effective Rayleigh numbers, agree at longer wavelengths with the observed anomalies and can produce the observed geoid slope-age behaviour. This Page. a clear indicator that a fracture zone exists in the ridge. We compared our results with geoid anomalies over the Udintsev fracture zone and found that the predicted geoid anomalies are in good agreement with the observed anomalies when the viscosity of (at least) the top layer is greater than one order of magnitude less than post-glacial rebound values (<10 20 Pas). Conclusion and Perspectives Confirming previous results [ , 1998 ], the new highly precise Pb isotopic data . These features include extinct ridges, minor fracture zone lineations, and seamounts. Show Source; Navigation. To the extent that oceanographic flows are stricfly Next topic (10) A geographical bar graph plot. From satellite gravity data, it has been predicted (2) that morphological transitions occur . The amplitude of this observed anomaly is well predicted if cooling lithosphere begins to accumulate lastic stresses at a temperature of 700C, consistent with the maximum depth of seismicity in the oceanic . (This page once was at an old link now listed in this package CITATION file as a note). Show Source; Navigation. Also labeled are the Mariana Trench (MT), the Caroline Ridge (CR), the We have also compared the calculated topographic steps to those . agulhas fracy sean menard fracture zone hasin lagann and croton fackcard plateau north scotia ace indian ridge heezen fracture zone eltanin fracture tharp fracture zone zone system scotia sean wornic enderry plain australia-antarctic basin udintsev fracture zone climate weddell weddell plain in mundsen plain pasire sea enderby shave pin . The "Orsi fronts" are a commonly used climatological map of Southern Ocean frontal distributions, published on the Southern Ocean Atlas Database Page after Orsi et al (1995). Naval Research Laboratory. Orsi and Park/Durand fronts in Spatial form. New Zealand, and through the Eltanin and Udintsev Fracture Zones in the central Pacic Ocean. Alternatively, independent movement of the Bellingshausen plate may have begun during chron C33, and be recorded by a change in the strike of the Udintsev Fracture Zone. Observations of the Antarctic Circumpolar Current Over the Udintsev Fracture Zone, the Narrowest Choke Point in the Southern Ocean. . However, we also compared the . A data set package with the "Orsi" and "Park/Durand" fronts as SpatialLinesDataFrame objects. Unique Geologic Features at Every World Grid Point. Regionally uniform stress orientations and relative magnitudes permit definition of . of the Udintsev and Eltanin Fracture Zone systems; and to have a line of stations under-neath the 10-day repeat satellite track to compare geostrophic sea-surface elevation and satellite altimetry. The output shows the sea-surface slopes along 42 descending Geosat tracks in the Eltanin and Udintsev fracture zone region in a Mercator projection. various fracture zones, such as the Ascension, Tasman, and Udintsev fracture zones, can be extended much closer to their respective continental margins. Using a three-layered viscosity structure for the upper mantle, results are presented for the effects of varying: (1) the viscosity contrast between the fluid layers: (2) the Rayleigh number based on the viscosity . The tectonic fabric map reveals many features which are not apparent on global bathymetric charts. The seismicity may have been linked to . East Acores Fracture Zone,East Aores Fracture Zone: fracture zone: N 36 30' 0'' W 26 0' 0'' 140: Central Basin Trough