Miocene to present oceanographic variability in the Scotia Sea and Antarctic Ice Sheet dynamics: Insight from revised seismic-stratigraphy following IODP Expedition 382

first_imgScotia Sea and the Drake Passage is key towards understanding the development of modern oceanic circulation patterns and their implications for ice sheet growth and decay. The sedimentary record of the southern Scotia Sea basins documents the regional tectonic, oceanographic and climatic evolution since the Eocene. However, a lack of accurate age estimations has prevented the calibration of the reconstructed history. The upper sedimentary record of the Scotia Sea was scientifically drilled for the first time in 2019 during International Ocean Discovery Program (IODP) Expedition 382, recovering sediments down to ∼643 and 676 m below sea floor in the Dove and Pirie basins respectively. Here, we report newly acquired high resolution physical properties data and the first accurate age constraints for the seismic sequences of the upper sedimentary record of the Scotia Sea to the late Miocene. The drilled record contains four basin-wide reflectors – Reflector-c, -b, -a and -a’ previously estimated to be ∼12.6 Ma, ∼6.4 Ma, ∼3.8 Ma and ∼2.6 Ma, respectively. By extrapolating our new Scotia Sea age model to previous morpho-structural and seismic-stratigraphic analyses of the wider region we found, however, that the four discontinuities drilled are much younger than previously thought. Reflector-c actually formed before 8.4 Ma, Reflector-b at ∼4.5/3.7 Ma, Reflector-a at ∼1.7 Ma, and Reflector-a’ at ∼0.4 Ma. Our updated age model of these discontinuities has major implications for their correlation with regional tectonic, oceanographic and cryospheric events. According to our results, the outflow of Antarctic Bottom Water to northern latitudes controlled the Antarctic Circumpolar Current flow from late Miocene. Subsequent variability of the Antarctic ice sheets has influenced the oceanic circulation pattern linked to major global climatic changes during early Pliocene, Mid-Pleistocene and the Marine Isotope Stage 11.last_img read more

The Latest: Goran Ivanisevic tests positive for coronavirus

first_img June 26, 2020 The Latest: Goran Ivanisevic tests positive for coronavirus Associated Press The former Wimbledon champion coaches top-ranked Novak Djokovic and was at the recent Adria Tour exhibition series in Serbia and Croatia.Djokovic and three other players have also tested positive for the virus after playing in the events. Grigor Dimitrov, Borna Coric and Viktor Troicki are the others.Ivanisevic won the Wimbledon title in 2001. He says he twice tested negative for the virus over the past 10 days but has now tested positive.Ivanisevic says “I would like to inform everyone who has been in contact with me that I tested positive and ask them to take extra good care of themselves and their loved ones.”The Croat says he has no symptoms but will self-isolate.center_img Share This StoryFacebookTwitteremailPrintLinkedinRedditThe Latest on the effects of the coronavirus outbreak on sports around the world:___Tennis great Goran Ivanisevic says he has tested positive for the coronavirus. ___More AP sports: https://apnews.com/apf-sports and https://twitter.com/AP_Sportslast_img read more

Give my regards to Broadway

first_imgEric Burse | Daily TrojanThe Trojan Marching Band and the USC Song Girls performed in Times Square this weekend, bringing USC spirit to an away game as fans and tourists alike watched. Members of the band traveled with the football team to New York City for the football game against Syracuse. The Trojans beat Syracuse 42-29.last_img