Another Indonesian Volcano Threatens to Erupt

OurAmazingPlanet Staff

Date: 23 November 2010 Time: 09:52 AM ET

Indonesia is on alert again for a possible volcanic eruption, this time from Mount Bromo, located on the eastern end of the Indonesian island of Java, according to news reports.

The eruption red alert comes just a couple weeks after Mount Merapi's relentless erupting killed more than 300 people. [Related: Mount Merapi's Devastation Seen from Space .]

"We raised the status of Bromo to the highest red alert level at 3:30 pm (0830 GMT) today. There's a chance of an eruption soon," government volcanologist Surono told AFP.

Bromo started rumbling to life on Nov. 8, the AFP reports, and plumes of smoke and ash were rising from the summit crater on Tuesday (Nov. 23).

But Bromo, unlike Merapi, lies in a less populated region, within the Bromo-Tengger-Semeru National Park. Merapi has displaced more than 200,000 people from nearby villages.

Bromo is a fairly active volcano ; it last erupted was in 2004, killing two tourists.

Bromo is located in the center of the Sandsea Caldera, itself only a portion of the larger Tengger Caldera (a caldera is the circular depression in the center of a volcano's summit). The Sandsea caldera formed around 8,000 years ago, in what must have been a massive eruption. Subsequent volcanic activity formed the cluster of cinder cones in the caldera's center, including Bromo.

According to Erik Klemetti of Big Think's Eruptions blog, Bromo is a different type of volcano than Merapi, one that tends to have smaller eruptions that blech out ash and perhaps small lava flows, but doesn't produce the large pyroclastic flows scorching rivers of gas and rock that stratovolcanoes like Merapi do.

Indonesia itself is a very volcanically and seismically active region that lies along the infamous Pacific Ring of Fire . One of the largest volcanic explosions in history, that of Krakatoa in 1883, occurred on the tiny volcanic island of the same name between Java and Sumatra, killing some 40,000 people. The remnant of that spectacular eruption, called Anak Krakatau, has also been rumbling and producing smoke recently.