MARUM Seminar

Dienstag, 17. April 2018 - 10:00 Uhr c.t.
MARUM Seminarraum 2070, 2. Etage
Prof. Michael J. Whiticar
(School of Earth and Oce­an Sci­en­ces, Uni­ver­si­ty of Vic­to­ria, Ca­na­da); pre­sent­ly: Fel­low at Han­se Wis­sen­schafts­kol­leg, Del­men­horst

Me­tha­ne, the most ab­un­dant or­ga­nic mole­cu­le on Earth, is ubi­qui­tous­ly dis­tri­bu­ted in rocks, se­di­ments, soils, wa­ter co­lumns of the geo­s­phe­re. Be­cau­se we still use me­tha­ne as a na­tu­ral gas fuel to run our en­er­gy eco­no­mies, it re­mains im­portant to un­der­stand its for­ma­ti­on, dis­tri­bu­ti­on and con­sump­ti­on. Howe­ver, it is also a strong GHG in the tro­po­s­phe­re cont­ri­bu­ting in­cre­a­sin­gly to our glo­bal ra­dia­tive­ly ba­lan­ce. By far, the lar­gest re­po­si­to­ries for me­tha­ne are the ma­ri­ne and ter­restri­al hy­dra­tes (~ 5 - 36 x 105 Tg CH4). It is pos­tu­la­ted that mas­si­ve, ca­ta­stro­phic re­lea­ses of me­tha­ne from hy­dra­tes to the tro­po­s­phe­re (‘Cl­a­thra­te Guns’) are re­s­pon­si­ble for the chan­ges in at­mo­s­phe­ric me­tha­ne, and dri­ve cli­ma­te chan­ge, in con­cert with CO2. Using sta­ble iso­to­pe si­gna­tu­res, this pre­sen­ta­ti­on ta­kes you on a cir­cui­tous walk through our re­se­arch on Hy­dra­te Ridge, San­ta Bar­ba­ra Ba­sin, north Ca­na­di­an per­ma­frost and Green­land ice to in­ves­ti­ga­te the ra­pid rise in me­tha­ne at the Youn­ger Dryas-Pre­bo­re­al tran­si­ti­on around 11 ky BP. The re­sults may sur­pri­se you as much as it did us.