Publications

Export 31 results:
Sort by: Author Title [ Type  (Desc)] Year
Journal Article
Gahagan, LM, Scotese CR, Royer JY, Sandwell DT, Winn JK, Tomlins RL, Ross MI, Newman JS, Muller RD, Mayes CL, Lawver LA, Heubeck CE.  1988.  Tectonic Fabric Map of the Ocean Basins from Satellite Altimetry Data. Tectonophysics. 155:1-&.   10.1016/0040-1951(88)90258-2   AbstractWebsite

Satellite altimetry data provide a new source of information on the bathymetry of the ocean floor. The tectonic fabric of the oceans (i.e., the arrangement of fracture zones, ridges, volcanic plateaus and trenches) is revealed by changes in the horizontal gravity gradient as recorded by satellite altimetry measurements. SEASAT and GEOSAT altimetry data have been analyzed and a global map of the horizontal gravity gradient has been produced that can be used to identify a variety of marine tectonic features. The uniformity of the satellite coverage provides greater resolution and continuity than maps based solely on ship-track data. This map is also the first global map to incorporate the results of the GEOSAT mission, and as a result, new tectonic features are revealed at high southerly latitudes.This map permits the extension of many tectonic features well beyond what was previously known. For instance, various fracture zones, such as the Ascension, Tasman, and Udintsev fracture zones, can be extended much closer to adjacent coninental margins. The tectonic fabric map also reveals many features that have not been previously mapped. These features include extinct ridges, minor fracture zone lineations and seamounts. In several areas, especially across aseismic plateaus or along the margins of the continents, the map displays broad gravity anomalies whose origin may be related to basement structures.

Bassett, D, Sandwell DT, Fialko Y, Watts AB.  2016.  Upper-plate controls on co-seismic slip in the 2011 magnitude 9.0 Tohoku-oki earthquake. Nature. 531:92-96.: Nature Publishing Group   10.1038/nature16945   Abstract

The March 2011 Tohoku-oki earthquake was only the second giant (moment magnitude Mw ≥ 9.0) earthquake to occur in the last 50 years and is the most recent to be recorded using modern geophysical techniques. Available data place high-resolution constraints on the kinematics of earthquake rupture, which have challenged prior knowledge about how much a fault can slip in a single earthquake and the seismic potential of a partially coupled megathrust interface. But it is not clear what physical or structural characteristics controlled either the rupture extent or the amplitude of slip in this earthquake. Here we use residual topography and gravity anomalies to constrain the geological structure of the overthrusting (upper) plate offshore northeast Japan. These data reveal an abrupt southwest–northeast-striking boundary in upper-plate structure, across which gravity modelling indicates a south-to-north increase in the density of rocks overlying the megathrust of 150–200 kilograms per cubic metre. We suggest that this boundary represents the offshore continuation of the Median Tectonic Line, which onshore juxtaposes geological terranes composed of granite batholiths (in the north) and accretionary complexes (in the south). The megathrust north of the Median Tectonic Line is interseismically locked, has a history of large earthquakes (18 with Mw > 7 since 1896) and produced peak slip exceeding 40 metres in the Tohoku-oki earthquake. In contrast, the megathrust south of this boundary has higher rates of interseismic creep, has not generated an earthquake with MJ > 7 (local magnitude estimated by the Japan Meteorological Agency) since 1923, and experienced relatively minor (if any) co-seismic slip in 20111. We propose that the structure and frictional properties of the overthrusting plate control megathrust coupling and seismogenic behaviour in northeast Japan.

Shum, CK, Werner RA, Sandwell DT, Zhang BH, Nerem RS, Tapley BD.  1990.  Variations of Global Mesoscale Eddy Energy Observed from GEOSAT. Journal of Geophysical Research-Oceans. 95:17865-&.   10.1029/JC095iC10p17865   AbstractWebsite

The global distribution of eddy kinetic energy has been synoptically observed from analysis of the Geosat Exact Repeat Mission (ERM) altimeter data collected for a 2-year period from November 1986 through November 1988. Using a technique developed by Sandwell and Zhang (1989), altimeter data from forty-four 17-day repeat cycles (2 years) were processed into sea surface slopes along the satellite ground track, averaged, and filtered to produce a mean sea surface slope profile having an estimated accuracy of 0.2 μrad (2 cm sea level change over 100 km distance). A series of global eddy kinetic energy maps, each averaged over 3 months, and their mean were then generated. The maximum mean eddy kinetic energy per unit mass exceeds 2000 cm^2/s^2 for most of the western boundary currents; however, it only reaches approximately 500 cm^2/s^2 for the Antarctic Circumpolar Current (ACC). More than 65% of the world ocean has relatively low variability with an eddy kinetic energy of less than 300 cm^2/s^2. Results obtained from this study are in general agreement with other Geosat ocean variability studies (e.g., Zlotnicki et al., 1989). However, significantly higher variability is found when compared with either Seasat or ship drift data. Significant seasonal variations were found in the Gulf Stream and Kuroshio currents. The ACC system exhibits no apparent seasonal variation.

Book Chapter
Sandwell, D.  2007.  Ocean Bathymetry and Plate Tectonics. Our changing planet : the view from space. ( King MD, Parkinson CL, Partington KC, Williams RG, Eds.).:149-152., Cambridge ; New York: Cambridge University Press Abstract

Examines what orbital imagery tells us about the atmosphere, land, ocean, and polar ice caps of our planet and the ways that it changes naturally, and in response to human activity.

Sandwell, DT, Anderson D, Wessel P.  2005.  Plates, plumes, and paradigms. Plates, plumes, and paradigms. ( Foulger GR, Natland JH, Presnall DC, Anderson DL, Eds.).:1-10., Boulder, Colo.: Geological Society of America Abstract
n/a
Sandwell, D, Smith B.  2007.  The San Andreas Fault: Adjustments in the Earth's Crust. Our changing planet : the view from space. ( King MD, Parkinson CL, Partington KC, Williams RG, Eds.).:94-96., Cambridge ; New York: Cambridge University Press Abstract

Examines what orbital imagery tells us about the atmosphere, land, ocean, and polar ice caps of our planet and the ways that it changes naturally, and in response to human activity.