Indonesian quakes: Pacific Rim gets physical

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Indonesia as a whole is very much a geological dictionary. The area seems directly plugged in to the Earth's ferocious geophysical power. It contains a lot of volcanoes, including the current version of the notorious Krakatoa volcano, called Anak Krakatau, “child of Krakatoa”. Anak Krakatau is the third of the Krakatoas, the original of which blew up in the Middle Ages, and caused a nuclear winter in Ireland, according to recent research.

In the 19th century, the modern Krakatoa blew up, causing massive tidal waves and killing at least 30,000 people. The monster Aceh quake in 2004 was itself unique. The USGS maps showed follow up quakes every day for a year afterwards. In fact, the area is still shaking. The present series of quakes is very persistent, many of the after shocks would qualify as significant earthquakes in their own right, if they weren't following an 8.4 force original earthquake.

Geophysics is a tough science at the best of times, and the Aceh quakes gave rise to some pretty impressive ideas. One theory I’ve heard is that quakes are part of the slow split of the India-Australia plate. According to this theory, when the plate splits, the Himalayas will collapse.

Anyone who's seen the USGS earthquake map of earthquakes over the last 30 days would agree that the Ring of Fire is living up to its name.

For some bizarre reason the dates are only from 6 September, but the map is a good indication of how active the Pacific Rim has been lately. To get specific maps of the Indonesian quakes, click on the "World" link top left of the page. A mouseover of Sumatra will give you a magnitude. Alternatively hit this link for a blow by blow of each quake.

The current quakes are along the main plate boundary, and extend from Burma to southern New Zealand on the Pacific Rim. The entire Pacific Rim is currently hyperactive.

The BBC has assembled a series of links around its article on the current quakes which explains the basics of earthquakes, and has some links to related sources. I’d suggest using the USGS link above, rather than theirs, however, which links to the main page, not directly to the Indonesian data. Clicking on an earthquake link will give a location map and data.