An impact event is a collision between astronomical objects causing measurable effects. Impact events have been found to regularly occur in planetary systems, though the most frequent involve asteroids, comets or meteoroids and have minimal effect. When large objects impact terrestrial planets such as the Earth, there can be significant physical and biospheric consequences, as the impacting body is usually traveling at several kilometres a second (a minimum of 11.2 km/s (7.0 mi/s) for an Earth impacting body), though atmospheres mitigate many surface impacts through atmospheric entry. Impact craters and structures are dominant landforms on many of the Solar System's solid objects and present the strongest empirical evidence for their frequency and scale. (Full article...)
Image 21The energy released produces tsunami waves. (from Tsunami)
Image 22An illustration of the rhythmic "drawback" of surface water associated with a wave. It follows that a very large drawback may herald the arrival of a very large wave. (from Tsunami)
Selected tsunami article
The 1992 Flores earthquake and tsunami occurred on December 12 on the island of Flores in Indonesia. With a magnitude of 7.8 and a maximum Mercalli intensity of VIII (Severe), it was the largest and also the deadliest earthquake in 1992 and in the Lesser Sunda Islands region. The earthquake was caused by slip on the Flores Thrust fault. This fault dips to the south underneath Flores Island. The epicenters of most earthquakes on the Flores Thrust are on Flores Island. (Full article...)