Cutting-Edge Research

     The primary focus of Dallas Abbott's present research is on submarine impact craters and their contribution to climate change and megatsunamis. This research grew out of work on the thermal history of the earth when Ann Isley and Dallas discovered that mantle plumes had the same periodicity as impact cratering events (Isley and Abbott, 2002, Journal of Geology, 110, 141-158). They did a compilation of impact cratering events and found that the record was woefully undersampled (Abbott and Isley, 2002. Earth and Planetary Science Letters, 205, 53-62).
     As a result, Dallas started to look for impact craters on the ocean floor. She found that Holocene age impact crater candidates could be located using a combination of bathymetry derived from satellite altimetry and the directions to the source of chevron dunes. Now, as part of the Holocene Impact Working Group, Dallas and colleagues focus on two goals: looking at the effect of submarine impacts on climate and determining if chevron dunes are megatsunami deposits.
    Of special interest is a candidate crater  in the Gulf of Carpentaria, northern Australia, with an inferred age of AD 572±86 (Abbott et al., 2007). The craters have produced impact spherules of magnetite, impact glass, and probable shocked quartz. The date of AD 572±86 is, within error, the same as the age of the climate downturn at AD 536. Ice core work is underway to see if the samples of the GISP2 ice core dating to 536 A.D. contain impact ejecta from the Carpentaria craters. They are also working on samples from chevron dunes in Madagascar to see if they contain impact ejecta.

     Dallas has participated in Earth2Class workshops since 2002. E2C teachers especially enjoy her ability to share her discoveries and explain how one question can lead into others.

Links to previous E2C Workshops:

• “Impact Craters Under the Sea" (Dec 2002)

• "Historic Impact Craters" (Apr 2004)

• "New Revelations about Impact Craters" (May 2005)

• "Recent Impact Craters and Human History" (Apr 2006)

• "New News about Impact Craters" (Apr 2007)

• "Evidence for Multiple Impact Craters Near and Far"  (Apr 2008)

• "What Really Happened? The Abiding Mystery of the Tunguska Impact 100 Years Later" (Nov 2008)

• "Tsunami in the Hudson: Evidence for a Large Event with a Source on the New Jersey Margin" (Mar 2010)

• "What Really Happened to the Sky and Ocean During the Dark Age Period of 534 to 544 A.D.?" (Nov 2010)

Links to selected Geological Society of America conference presentations :