Physics Department Seminar University of Alaska Fairbanks

J O U R N A L    C L U B

Nuclear Blast Surrogates in the Atmosphere:
The flux of small object collisions with Earth
Curt Szuberla
Physics Dept/GI UAF

The Peoples' Republic of China conducted the last atmospheric nuclear weapon test in 1980. Despite this, two of UAF's infrasound observatories (one here on campus and the other on the Ross Ice Shelf), are designed to monitor for just such testing activity as part of the verification regime of the Comprehensive Nuclear-Test-Ban Treaty. Happily, nature has provided us with a steady supply of surrogate blasts in the atmosphere with which to test our monitoring systems. Small objects (< 50-100 m) collide with the Earth's atmosphere quite frequently, but do not typically strike the ground as a single body. Rather, they explode as a result of sudden heating resulting in a fireball or bolide. Bolides can still do considerable damage upon impact — the Tunguska event was likely such an impact. Such events are often expressed in the equivalent explosive yield in TNT; a Tunguska-class event is considered to be of order 10 MT. In this talk I'll cover the basics of bolide impacts, how they are monitored and the contribution of infrasonic data analysis to constraining the flux of bolide impacts.

Friday, 3 October 2008
Globe Room, Elvey Building
3:45 PM