Flatiron Seminars 2022

Should We Worry about Asteroid-Generated Tsunamis?

by Marsha Berger (CCM)

Time: 4-5 pm (Seminar) + 5-6:30 pm (Reception)
Location: 162 Fifth Ave, 2nd floor auditorium (Seminar) + 162 2nd floor promenade (Reception)
In 2013, an asteroid with a 20 meter diameter exploded in the atmosphere over Chelyabinsk, Russia, causing injury and damage 20 kilometers away but no deaths.  We are studying the question of what would occur if such an airburst happened over the ocean.  Would the blast wave generate a tsunami that could threaten coastal populations far away?

We show simulations of tsunami propagation from asteroid-generated airbursts. We then present a 1D model with an explicit solution to understand the unexpected results.  The model is then extended to explore the effects of dispersion and compressibility.  We end with a discussion of appropriate tools to study the more serious case of an  asteroid that impacts the water.
This work builds on a long-running project to simulate earthquake generated tsunamis.  The software uses an AMR adaptive strategy combines with a Cartesian grid treatment of ocean boundaries, using real bathymetry from databases.