... and potential deaths from superfires.U.S. government estimates of urban-fire casualties that might be triggered by the detonation of a 1 megaton meg·a·ton n. Abbr. MT A unit of explosive force equal to that of one million metric tons of TNT. meg (MT) nuclear bomb have been based on the assumption that the casualty rate for any given peak shock wave pressure, or "overpressure overpressure, n excessive pressure applied at the end of a physiologic joint range to confirm the severity of pain, thus helping determine the manual treatments. ," would be similar to that experienced in Nagasaki and Hiroshima. But research by Theodore Postol Theodore A. Postol (1946 - ) is a Professor of Science, Technology, and International Security at MIT and a prominent critic of the effectiveness of missile defense. He received both his undergraduate degree in physics as well as his PhD in nuclear engineering from MIT. , a senior analyst at Stanford university's Center for International Security and Arms Control arms control Limitation of the development, testing, production, deployment, proliferation, or use of weapons through international agreements. Arms control did not arise in international diplomacy until the first Hague Convention (1899). , calls that assumption into question. His calculations indicate that the 15 million deaths this scaling rule suggests might result from 100 1-MT bombs dropped on cities would underestimate -- by a factor of two to foure -- the likely fire deaths. The thermal energy thermal energy Internal energy of a system in thermodynamic equilibrium (see thermodynamics) by virtue of its temperature. A hot body has more thermal energy than a similar cold body, but a large tub of cold water may have more thermal energy than a cup of boiling delivered to regions experiencing similar peak overpressures varies with bomb yield. for example, the 5 pounds per square inch Noun 1. pounds per square inch - a unit of pressure psi pressure unit - a unit measuring force per unit area (psi) overpressure zone for a 1-MT bomb would likely experience at least 3.5 times more heat than the 5-psi overpressure zone associated with the 0.15-MT Hiroshima bomb. The zone in which blast-initiated fires develop also scales up with bomb yield. For example, Postol's data indicate that the fire-zone radius associated with a 1-MT blast could be eight miles, and that the 5-psi overpressure zone might be as far as three miles inside this fire zone's perimeter. If true, that might give blast survivors only 10 to 30 minutes (or less) to escape before small fires coalesced co·a·lesce intr.v. co·a·lesced, co·a·lesc·ing, co·a·lesc·es 1. To grow together; fuse. 2. To come together so as to form one whole; unite: into a giant "suprfire" -- with gale force winds circulating poisonous combustion gases and with ground-level temperatures above the boiling point of water. This prospect does not support the earlier speculation that even 30 percent might escape the 5-psi zone relatively unharmed or that only about 30 percent would die outright. Finally, Postol's data indicate that cities don't have to be as dense -- and hence, fuel-rich -- as Dresden during the 1940s to support a superfire. The higher winds that would accompany the 1-MT bomb's larger fire zones might be able to whip up even a lightly built-up, burning city into a firestorm, he says. |
|
||||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion