“What Really Happened? The Abiding Mystery of the Tunguska Impact 100 Years Later” with Dallas Abbott (Nov 2008)

by | Jul 25, 2023 | Impact Craters

with Dr. Dallas Abbott

with Dr. Dallas Abbott

Originally presented 15 Nov 2008

Dallas Abbott has shared her fascinating research about impact craters on the sea floor and the effects on land in many previous E2C programs. Earlier this year, Dallas had the opportunity to travel to Siberia as part of an international conference marking the centennial of the famous Tunguska event. In this year’s E2C, she will share what was learned about this (literally) earth-shattering event.

Introduction to this Workshop

Here is the slide show introduction for this workshop (pdf format).

Cutting-Edge Research                             

The primary focus of Dr. Abbott’s present research is on submarine impact craters and their contribution to climate change and megatsunamis.  This research grew out of her work on the thermal history of the earth when Ann Isley and Dr. Abbott 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, she started to look for impact craters on the ocean floor.   She found that the 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. 

Dr. Abbott is part of the Holocene Impact Working Group that is focusing on two goals: looking at the effect of submarine impacts on climate and determining if chevron dunes are megatsunami deposits.   They have located a candidate crater set in the Gulf of Carpentaria, 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.  We are also working on samples from chevron dunes in Madagascar to see if they contain impact ejecta.

Dallas’s investigations have attracted attention in many parts of the world. The New York Times ran a feature story in 2006: http://www.nytimes.com/2006/11/14/science/14WAVE.html?pagewanted=all

     Dallas was also interviewed for the popular Brasilian television news program “Fantastico,” which appeared shortly before Dr. Passow visited his E2C collagues in August 2008. Here is the link to the online story: http://fantastico.globo.com/Jornalismo/FANT/0,,MUL710601-15605,00-CIENTISTA+ENCONTRA+EXPLICACAO+PARA+DILUVIO+BIBLICO.html

Dr. Abbott also leads the Summer Undergraduate Internship program at LDEO that brings about thirty extremely qualified students from Columbia and other colleges across the country to work with scientists on a variety of research projects. Many have gone on to present their results at AGU, GSA, and other scientific meetings, and then graduate studies in the geosciences.

Katherine Cagen worked with Dr. Abbott during here during her junior and senior years at the Horace Mann School. Her research placed 1st in Earth Science category at the 2008 Intel International Science and Engineering Fair.

Links to previous E2C Workshops presented by Dr. Abbott:

Impact Craters Under the Sea (2002)

Did a Bolide Impact Cause Catastrophic Tsunamis in Australia and New Zealand? (2004) http://www.earth2class.org/k12/w8_s2004/content.htm

New Revelations about Impact Craters (2005)

Recent Impact Craters and Human History (2006)

New News about Impact Craters (2007)

Classroom Resources

“Impact Earth” from Purdue University

[An “Earth2Class Workshops for Teacher” Module]
Created by: Mirtha Landaira, Lawrence Leung, and Linda McCall
E2C Summer Curriculum Development Workshop, Summer 2004

Impact Simulation Model suggested by Dallas Abbott:
“Earth Impact Effects Program”: an easy-to-use, interactive web site for estimating the regional environmental consequences of an impact on Earthhttp://www.lpl.arizona.edu/impacteffects/

 Hawai’i Space Grant College Teacher Page


 Impact Cratering on a Rainy Day

 Explore Craters

 “Crater Crazy” by Andrea Gianopoulos

Other Resources for This Topic

Specifically Tunguska:

Tunguska Event. From Russian Federation for Basic Research

The Tunguska Event — 100 Years Later. From Science@ NASA

Fire in the Sky–Tunguska at 100. From BBC News

Sandia Computers Offer New Explanation of Tunguska Disaster. From Sandia National Laboratories.

1908 Siberia Explosion: Reconstructing an Asteroid Impact from Eyewitness Accounts–A project in Astronomical Art, Science, and History (in Progress) by William K. Hartmanhttp://www.psi.edu/projects/siberia/siberia.html

Tunguska. From Tunguska.ru
More generally, Impacts

National Geographic’s Asteroids–Deadly Impacthttp://www.nationalgeographic.com/asteroids/index.html

“Meteors and Meteorites” from Astronomy 161, University of Tennessee, Knoxville

“Comets” from Astronomy 161, University of Tennessee, Knoxvillehttp://csep10.phys.utk.edu/astr161/lect/comets/comets.html

Asteroid and Comet Impact Hazards from NASA Ames Research Center