Visible Shock Wave Rocks Japanese Volcano in Slo-Mo

[n2doc]

By Michael Reilly | Thu Jan 21, 2010 03:56 PM ET
We can all agree that volcanic explosions are filled with awesome. But get too close, and you're toast. The camera monitoring Sakurajima Volcano in southern Japan was definitely well within the danger zone when it snapped this stunning sequence last month of a visible shock wave propagating out from an explosion in the Showa crater:



Notice the rocks and boulders being flung out from the ash cloud at high speed; had a human been present, s/he would've probably got a nasty bonk on the head, at best. But this is a tiny outburst by Sakurajima's standards -- it used to be an island until a 1915 eruption sent lava pouring into Kagoshima Bay and connected the volcano to mainland Kyushu.

One of the reasons Sakurajima is so well outfitted with sensing equipment is its location: it's about 4 kilometers (2.5 miles) across the bay to downtown Kagoshima, a city of about 600,000 people (see satellite image below). Ash routinely sprinkles the town, and the local airport sometimes has to ground or reroute flights to avoid volcanic clouds.


Sakurajima with Kagoshima city in foreground - Kita-dake (left), Minami-dake (right)


If animation doesn't work try these links:

http://news.discovery.com/earth/visible-shock-wave-rocks-japanese-volcano-in-slo-mo.html
http://www.photovolcanica.com/VolcanoInfo/Sakurajima/Sakurajima.html