DR. MARTA E. TORRES
Oregon State University
2004-2005 Distinguished Lecturer
Methane-Ice in Marine Sediments: Where, How and Why We Study These Deposits
2004-2005 Distinguished Lecturer – Marta Torres
Methane hydrate is a crystalline substance that looks like ice and forms when water and methane are combined at high pressure and low temperature. Methane hydrate deposits are common along continental margins, where natural gas originates from the decomposition of organic matter. Within the sediments and at the seafloor, complex and complementary microbial relationships produce and consume methane, thus affecting the methane inventories and methane hydrate distribution. Additionally, oceanographic changes and earthquake activity can destabilize these deposits, resulting in submarine landslides and massive methane release. Methane is a greenhouse gas, and destabilization of methane hydrates may have affected Earth’s climate in the past. Data obtained by ODP in passive (Leg164, Blake Ridge) and convergent (Legs 112 and 201, Peru margin; Leg 141, Chile Triple Junction; Leg 146, Cascadia margin; and Leg 204, Hydrate Ridge) margins have been critical in improving our understanding of the processes that control hydrate distribution in marine sediments. An exciting result of Leg 204, is the discovery of the coexistence of massive methane hydrate, free gas, and highly saline pore water near the summit of Hydrate Ridge, off Oregon. These results reflect the dynamic nature of this system, indicate that hydrate is forming very rapidly in the upper reaches of sediment, and explain the bubble plumes that emerge from topographic highs.
Dr. Torres served as a shorebased investigator for ODP Leg 112, as staff scientist for Legs 124 (Sulu Sea) and 128 (Japan Sea), and sailed as an inorganic geochemist on Legs 141 and 204.
LECTURE SCHEDULE
October 25, 2004 – Grand Valley State University
March 7, 2005 – Louisiana State University
March 9, 2005 – University of Georgia
March 11, 2005 – Colorado School of Mines
April 21, 2005 – University of St. Thomas
April 22, 2005 – New Mexico Highlands University