Now showing items 31-40 of 1145
Age systematics of two young en echelon Samoan volcanic trails
(American Geophysical Union, 2011-07-29)
The volcanic origin of the Samoan archipelago can be explained by one of three models, specifically, by a hot spot forming over a mantle plume, by lithospheric extension resulting from complex subduction tectonics in the ...
Stratigraphic record of Holocene coseismic subsidence, Padang, West Sumatra
(American Geophysical Union, 2011-11-23)
Stratigraphic evidence is found for two coseismic subsidence events that underlie a floodplain 20 km south of Padang, West Sumatra along the Mentawai segment (0.5°S–0.3°S) of the Sunda subduction zone. Each earthquake is ...
Deglacial diatom productivity and surface ocean properties over the Bermuda Rise, northeast Sargasso Sea
(American Geophysical Union, 2009-12-12)
Diatom assemblages document surface hydrographic changes over the Bermuda Rise. Between 19.2 and 14.5 ka, subtropical diatom species and Chaetoceros resting spores dominate the flora, as in North Atlantic productive regions ...
Molecular characterization of dissolved organic matter associated with the Greenland ice sheet
Subsurface microbial oxidation of overridden soils and vegetation beneath glaciers and ice sheets may affect global carbon budgets on glacial-interglacial timescales. The likelihood and magnitude of this process depends ...
Timescales of magmatic processes and eruption ages of the Nyiragongo volcanics from 238U-230Th-226Ra-210Pb disequilibria
The silica-undersaturated Nyiragongo volcanics, located in the East African rift, have globally unique chemical compositions and unusually low viscosities, only higher than carbonatite lavas, for terrestrial silicate ...
A decadally-resolved paleohurricane record archived in the late Holocene sediments of a Florida sinkhole
A 4500-year record of hurricane-induced storm surges is developed from sediment cores collected from a coastal sinkhole near Apalachee Bay, Florida. Recent deposition of sand layers in the upper sediments of the pond was ...
Deep-sea mining of seafloor massive sulfides
The potential emergence of an ocean mining industry to exploit seafloor massive sulfides could present opportunities for oceanographic science to facilitate seafloor mineral development in ways that lessen environmental harms.
Distribution of melt along the East Pacific Rise from 9°30′ to 10°N from an amplitude variation with angle of incidence (AVA) technique
(Oxford University Press, 2015-06)
We examine along-axis variations in melt content of the axial magma lens (AML) beneath the fast-spreading East Pacific Rise (EPR) using an amplitude variation with angle of incidence (AVA) crossplotting method applied to ...
The continental drift convection cell
(John Wiley & Sons, 2015-06-02)
Continents on Earth periodically assemble to form supercontinents and then break up again into smaller continental blocks (the Wilson cycle). Previous highly developed numerical models incorporate fixed continents while ...
Evolution of oceanic margins : rifting in the Gulf of California and sediment diapirism and mantle hydration during subduction
(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2013-06)
This thesis investigates three processes that control the evolution of oceanic margins. Chapter 2 presents seismic images of a ~2-km-thick evaporite body in Guaymas Basin, central Gulf of California. In rifts, evaporites ...