Download Catastrophic Events Caused by Cosmic Objects by V.V Adushkin (Editor), I.V. Nemchinov (Editor) PDF

By V.V Adushkin (Editor), I.V. Nemchinov (Editor)

An asteroid or comet will unavoidably strike the Earth a few day, and most likely reason nice destruction. This quantity considers dangers because of collisions with cosmic gadgets, relatively in gentle of contemporary investigations of affects via the authors. every one bankruptcy, written by means of knowledgeable, includes an outline of a side and new findings within the box. insurance describes and numerically estimates the most damaging results.

Show description

Read Online or Download Catastrophic Events Caused by Cosmic Objects PDF

Similar nonfiction_2 books

Private Solutions for Infrastructure in Lesotho

The file attracts on inputs from discussions with the woking staff participants from the govt. in addition to with representatives of the non-public area.

Additional info for Catastrophic Events Caused by Cosmic Objects

Example text

3 Spectrum of Seismic Signals All buildings, bridges, and other structures can vibrate with small amplitudes without being damaged. Every structure and element of a structure has many periods of vibration. For a majority of structures the most important is the longest one. The ground motion caused by an impact contains oscillations of many different frequencies. Short-period or high-frequency waves are absorbed by the ground more readily than lower frequencies. The greater the distance from a source, the larger is the fraction of a seismic signal remaining in the low-frequency part of a spectrum.

A wide shelf or reef decreases the wave height two to three times. Estimates of tsunami waves caused by a stony body with a diameter of 300 m and initial velocity 20 km·s−1 striking the ocean at a distance of 1,900 km from the US shore (Chesley and Ward 2005) show that the number of people at risk is approximately 106 , and the potential destruction of infrastructure amounts to about 100 billion US dollars. 6 Dispersion and Breaking of Waves Dispersion influences the propagation of waves in water at large distances.

Radiation efficiency for the case of the impact on a target in vacuum depends on velocity, but on average the efficiency is very low ( ≈ 10−4 − 10−2 ) due to transition of a large part of impactor kinetic energy into the target and cooling of an expanding plume. , the Moon) (Ortiz et al. 2000), and asteroids. Such values are adopted in the CMM code for all impacts; but in cases on the Earth with dense atmosphere and not very large bodies, these values severely underestimate real radiation efficiency.

Download PDF sample

Rated 4.54 of 5 – based on 40 votes