The South Coast Geological Society welcomes you to join our monthly meeting on March 12th, at 6pm to be held at The Chartroom, CSU Long Beach. We are delighted to host Dr. Rick Behl, Professor of Geological Sciences and Department Chair, who will present his topic: The Santa Barbara Record of Two Volcanic Winters Triggered by Twin Yellowstone Supervolcano Eruptions 631,000 years ago.
Richard Behl, with James Kennett, Walter Dean, Chris Sorlien, and Craig Nicholson
Large historic volcanic eruptions like Tambora (1816) or Krakatoa (1883) influenced the composition of the upper atmosphere and changed the radiation balance of the entire Earth. These produced the “year without summer” and fabulous crimson-hued sunsets immortalized in paintings from the 19th century. It is postulated that much larger supervolcano eruptions like Toba (74 ka) would produce even greater, global “volcanic winter” effects. Researchers have created computer models of the possible effects, but there is scant data on the actual result of such catastrophic eruptions, because they occurred so long ago that the Neanderthals living at the time didn’t document their observations very well. So, that’s where the science of paleoclimatology comes in.
A sedimentary paleoclimate record from Santa Barbara Basin, California provides an unprecedented high-resolution climatic history of the last Yellowstone supervolcano eruption, one of the largest of the Quaternary. The Lava Creek B ash (631.3 +/- 4 ka), identified by its unique geochemical fingerprint, occurs as two thin tephra layers, distinct in sediment composition and particle size from the background organic-rich hemipelagic mud. This ash fall deposit, widely distributed over western North America, records the massive explosive volcanic episode that formed the present vast Yellowstone volcanic caldera. For the first time, this tephra has been directly compared with a climatic record with decadal resolution that demonstrates that the volcanism was precisely coincident with, and therefore likely the cause of, two episodes of abrupt sea-surface cooling of ~3 degrees C in Santa Barbara Basin. Each of these volcanic winters lasted at least 80 years, far longer than predicted by computer models based on atmospheric dust and sulfur loads, and started and stopped rapidly. These results suggest involvement of strong, positive climatic feedbacks including surface albedo, ice and oceanographic effects.
“Edvard Munch’s painting The Scream (1893), was inspired by the brilliant sunsets caused by the final Krakatoa eruption in 1883.”
Richard (Rick) Behl is Professor of Geological Sciences at California State University Long Beach, and Director of the MARS Project (Monterey And Related Sediments) industrial affiliates program. Rick earned his Bachelors degree from the University of California (UC) San Diego in 1978, his PhD at UC Santa Cruz in 1992, and was a Post-Doctoral Fellow at UC Santa Barbara from 1992-1995. His expertise is in the sedimentology and sedimentary petrology of hemipelagic and pelagic sediments, and their relationship to climatic, oceanographic, and tectonic change. Behl’s research focuses on the Quaternary Santa Barbara Basin and the petroliferous Miocene Monterey Formation that is composed of a complex suite of biogenic and diagenetic rocks. Rick has participated in numerous international marine geologic expeditions, and led dozens of field trips and short-courses for professional organizations, international conferences, and industry. He has written more than 50 scientific articles and one controversial book. Behl and his students have made more than 150 conference presentations at regional through international conferences. Rick was an AAPG Distinguished Lecturer, was named a Distinguished Educator and President-Elect of the AAPG-Pacific Section, was elected a Fellow of the Geological Society of America and given lifetime Honorary Membership in the Society for Sedimentary Geology-Pacific Section.
Parking permits will be provided at the LOT E11 entrance courtesy of the CSULB Department of Geological Sciences. Parking is only valid in LOT E11.
Directions to Lot E11, from 22 West, turn right on West Campus Drive, turn right into the 3rd parking lot (E11). Student Volunteers will distribute the parking passes at the entrance of the parking lot (E11). Directional signs will be posted for your assistance. See the map below for localities of parking lot E11 and The Chartroom.