effusive eruption
eklemetti | July 1, 2008
Update 7/2/08: Sounds like the lava flows from Llaima are increasing ... or that there are more of them. The lava flows, as mentioned below, pose a threat to melt the ice on the volcano and produce lahars, or at least flooding.
Lots of news this morning about a new eruption at Llaima in Chile. The composite volcano is in south central Chile (the lakes region) about 430 miles south of Santiago. This is at least the third time this year that Llaima has erupted, and this time a lava flow is heading down the volcano towards the Rio Calbuco as far as 800 m downslope. The fear is the lava flow…
eklemetti | June 20, 2008
Not much in the way of science to add here, but photographers at Hawai'i Volcanoes National Park are still busy around the clock documenting the summit vent activity at Kilauea that started in March. Most of the activity is steam escaping from the vent, but at night, the vent glows red, proving just how close to the surface the magma is right now. Occasionally, the volcano throws out some volcanic clasts, probably in phreatomagmatic (water/magma interaction) explosions. The USGS Hawaii Volcano Observatory has a nice series of photos of the current activity and research as well, mostly…
eklemetti | June 9, 2008
Today, I saw a report that a dome on Arenal in Costa Rica had collapsed last Friday (report in Spanish, but good picture of the event), producing a block & ash flow that left a 800-meter scar on the volcano's flank. No one was injured during the avalanche, but tourists were evacuated as a precaution. There have been minor rock fall related to the andesite lava that has been erupting over the last year, but apparently this is the first major avalanche.
This shows the fine line between an effusive (lava flow dominated) eruption and explosive (pyroclastic dominated) eruption. Although this…
eklemetti | June 6, 2008
I had been looking for some pictures of the recent eruption of Cerro Azul in the Galapagos, and finally I found some posted on the BBC. There are some rather stunning pictures of the rift eruption (#3), the lava flows heading downslope (over older lava flows, #4) and even a little lava spatter (#1).Â