• AS_UCSB twitter avatar
    Color With COSWB WEDNESDAY, May 4th 7 PM - 8:30 PM @ Santa Cruz Main Lounge
    39 min 14 sec ago
  • AS_UCSB twitter avatar
    “SCREENWRITING” with Sean Lieberman, Wednesday, May 4, noon to 1 p.m. AS Annex, Building 434, Room 141H. https://t.co/Z8HdDhVzss
    52 min 42 sec ago
  • UCSBgauchos twitter avatar
    Carter makes his return, @UCSB_Baseball edges Pepperdine to win 30th game of '16. RECAP >>> https://t.co/T7hqzVP5eM https://t.co/izazQZyNs5
    15 hours 53 min ago
  • ucsantabarbara twitter avatar
    Holocaust survivor Eva Kor to talk about surviving & forgiving the Angel of Death at Auschwitz on May 5th at #UCSB. https://t.co/5KMwhu8Fm8
    15 hours 57 min ago
  • UCSBgauchos twitter avatar
    Bauman Climbs Into Top Individual Spot, Gauchos Drop to Third at Big West Tournament https://t.co/qLqS9JsBcL
    18 hours 27 min ago
  • UCSB_GradPost twitter avatar
    Writing effective cover letters for non-academic jobs https://t.co/GOEZWMJDAb #UCSB #ucsbgradpost
    18 hours 34 min ago
  • UCSBgauchos twitter avatar
    UCSB Basketball Adds Ohio State Transfer Mickey Mitchell https://t.co/PBLD50TWdm
    19 hours 2 min ago
  • UCSBgauchos twitter avatar
    @ucsbtennis will head down to USC to play Georgia Tech! #SelectionTuesday https://t.co/UbzG82vxFL
    19 hours 25 min ago
  • ArtsandLectures twitter avatar
    Discover Vivian Maier, a mysterious nanny who secretly took more than 100,000 photographs: https://t.co/xXrGiRRNWk https://t.co/rieD9kk2gO
    19 hours 51 min ago
  • UCSBgauchos twitter avatar
    @UCSBWTennis will open the NCAA Tourney w/ Kansas! #GoGauchos #SelectionTuesday https://t.co/jFHDMWA9Ql
    20 hours 18 min ago
  • UCSBgauchos twitter avatar
    Cullen Irons of UCSB MVB has been named @AVCAVolleyball Asst. Coach of the Year. Congrats C! https://t.co/yZrAVbtcMX https://t.co/novXnIXr7T
    20 hours 42 min ago
  • UCSBgauchos twitter avatar
    It's Selection Tuesday for our tennis teams! Women's bracket will be announced at 2 & the men's will be at 2:30 https://t.co/AY9iq60xwg
    21 hours 4 min ago
  • ArtsandLectures twitter avatar
    Curious about Santa Barbara's economic forecast? Santa Barbara County Economic Summit --> https://t.co/aefNyNmlZ1 https://t.co/RdZunTStr4
    22 hours 3 min ago
  • UCSB_GradPost twitter avatar
    View the 2016 UC Grad Slam presentations online https://t.co/5Jxul7yOyb #UCSB #ucsbgradpost
    22 hours 12 min ago
  • ucsantabarbara twitter avatar
    What drives genetic diversity in Hawaiian coral reefs? UCSB marine biologist investigates: https://t.co/X1cz0DVl4K https://t.co/2Sa6eBPxXw
    1 day 41 min ago

EVIDENCE FOR HISTORIC GLOBAL WARMING PUBLISHED IN SCIENCE

Thursday, November 18, 1999 - 16:00
Santa Barbara, CA

By analyzing a core of sediments taken from the ocean floor, scientists have discovered strong evidence linking a dramatic period of global warming, approximately 55.5 million years ago, to a massive release of methane, an event that resulted in an extensive die-off of deep sea dwelling organisms, according to this week's issue of the journal Science.

The warming, referred to as the "latest Paleocene thermal maximum" or LPTM, occurred over a 10,000 to 20,000-year interval and corresponds to the appearance of numerous mammals (including primates) and the extinction or temporary disappearance of many deep-sea species. (This period was originally discovered by James P. Kennett a University of California, Santa Barbara geology professor and his student Lowell Stott.)

Co-author Dorothy Pak, researcher in the Department of Geological Sciences and the Marine Science Institute of the University of California, Santa Barbara, explained that the new information is the "first tangible evidence for a methane dissociation event," a concept that has long been hypothesized.

According to the hypothesis, vast quantities of methane were stored as frozen gas hydrate in the upper few hundred meters of continental slope sediments before the latest Paleocene thermal maximum. "Long-term global warming during the late Paleocene pushed the ocean-atmosphere system past a critical threshold, causing warm surface waters to sink, and intermediate to deep ocean temperatures to rise by approximately 4 to 8 degrees centigrade," according to the Science article.

The result was a chain of reactions in the global carbon cycle as the methane melted and was released in bubbles that interacted with dissolved oxygen, "adding carbon to all reservoirs of the global exogenic carbon cycle."

"Higher bottom water temperature, lower dissolved oxygen, changes in surface water productivity, and more corrosive waters killed many of the deep-sea species," according to the article. "On land, higher partial pressure of carbon dioxide and elevated temperatures quickly opened high-latitude migration routes for the widespread dispersal of mammals. Over several hundred thousand years, global carbon and oxygen cycles gradually returned to equilibrium conditions after the LPTM, although marine and terrestrial ecosystems were forever changed."

Pak explained that the sediment core, removed as part of the Ocean Drilling Program, was taken from an area known as the Blake Nose, a promontory on the continental shelf off the coast of Florida. She said that the core shows disturbed sediment, evidence of a submarine landslide layer that fits with the theory of the melting of buried methane--methane clathrates--from an ice-like solid into a gas.

The article concludes with a call for further research, "Even though our results suggest that methane was released from the Blake Nose region, during the LPTM, the mass of methane from this region alone is insufficient to explain the magnitude of global perturbations at the LPTM. Other sections deposited on the middle to lower slope during the LPTM also must exhibit features similar to those reported here."

Besides Pak, co-authors on the paper are: Miriam E. Katz and Kenneth G. Miller from Rutgers University, Piscataway, New Jersey, and Gerald R. Dickens from James Cook University, Townsville, Queensland, Australia.