Damage from comet-asteroid impacts with earth

Only a small fraction of the Earth-crossing asteroids, ECAs, have been found and cataloged. Uncataloged ECAs can hit the atmosphere of Earth without warning. Long-period comets may give as little as two months warning before impact. The damage ranges from fires and blastwaves from energy dissipation in the atmosphere to craters, earthquakes, and tsunami from ground impact. Tsunami damage is particularly severe. An asteroid 5-6km in diameter impacting in the mid Atlantic would cause substantial tsunami damage to both Europe and North America: the tsunami would run all the way to the Appalachians in the upper two-thirds of the United States and to the mountains of the Iberian Peninsula in Europe. Tsunami heights along the Iberian Peninsula can reach several hundred meters. The tsunami heights would be less in Northern Europe due to the shallow continental shelf in this region. (C) 1999 Elsevier Science B.V. All rights reserved.