HR: 1340h
AN: OS43A-0986    [Abstracts]
TI: Volcanic Structure of the Gakkel Ridge at 85°E
AU: * Willis, C
EM: ccwillis@whoi.edu
AF: Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, MA 02543,
AU: Humphris, S
AF: Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, MA 02543,
AU: Soule, S A
AF: Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, MA 02543,
AU: Reves-Sohn, R
AF: Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, MA 02543,
AU: Shank, T
AF: Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, MA 02543,
AU: Singh, H
AF: Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, MA 02543,
AB: We present an initial volcanologic interpretation of a magmatically-robust segment of the ultra-slow spreading (3- 7 mm/yr) Gakkel Ridge at 85°E in the eastern Arctic Basin based on surveys conducted during the July 2007 Arctic GAkkel Vents Expedition (AGAVE). A previous expedition (2001 AMORE) and seismic stations in the area found evidence for active hydrothermal circulation and seismicity that suggested volcanic activity may be ongoing at 85°E. We examine multi-beam bathymetric data, digital imagery, and rock and sediment samples in order to determine the nature of volcanic accretion that is occurring in this environment including the distribution of flow types and their relationship to features of the axial valley. Raw multi-beam bathymetric data was logged by the Kongsberg EM 120 1°x1° multi-beam echo sounder aboard the icbreaker IB Oden. Digital imagery was recorded on five video and still cameras mounted on the CAMPER fiber-optic wireline vehicle, which was towed 1-3m above the seafloor. Digital imagery was recorded on thirteen CAMPER drift-dives over interesting bathymetry including: a volcanic ridge in the axial valley named Duque's Hill, and Oden and Loke volcanoes that are part of the newly discovered Asgard volcanic chain. Talus, lava flows, and volcaniclastics were sampled with the clamshell grabber and slurp suction sampler on CAMPER. A variety of lava morphologies are identified in the imagery including large basalt pillows with buds and other surface ornamentation, lava tubes, lobates, sheet flows, and a thick cover of volcaniclastic sediment over extensive areas suggestive of explosive volcanic activity.
DE: 3045 Seafloor morphology, geology, and geophysics
DE: 3075 Submarine tectonics and volcanism
SC: Ocean Sciences [OS]
MN: 2007 Fall Meeting