Crater Lake
eklemetti | July 4, 2010So, I've had requests on the blog to help to do some defining of volcanologic terms on the blog, so I thought I'd try a new column called Eruptions Word of the Day. I'm not sure how often it will run, but let's give it a try.
Eruptions Word of the Day for July 5, 2010: Dacite
Dacite is a magma type defined by silica (SiO2) content between 63-68 (or 69) weight percent. That is the textbook definition, but some other typical characteristics of dacite lavas (or magmas) is the presence of certain minerals: plagioclase feldspar and hydrous minerals (containing water in their mineral structure)…
eklemetti | July 27, 2009Again, sorry about the paucity of posts. Getting prepared to move 3/4 of the way across a continent will do that. Look for the next Volcano Profile, this time for Erebus in Antarctica, to be posted sometime in the next week or so.
We did get some news over the weekend of a large eruption at Shiveluch. The volcano in Kamchatka has been active all summer, but on Saturday it produced a 5,000 meter / ~23,000 foot ash plume. This was accompanied by 170 earthquakes and multiple avalanches, likely produced by the collapsing dome on the summit of the volcano. There is a little more information about…
eklemetti | June 26, 2009
Chaiten in Chile erupting in January 2009. Even after over a year of activity, Eruptions readers are still captivated by the volcano.
Thanks for sending me your questions about volcanoes and volcanism. I'll try to tackle some hear - but as always, keep the questions coming! Send them to
For those of you who have submitted a question but don't see the answer here, do not fret. Likely it just means that I needed to do a little more research into the question and will get to it in a later mailbag!
So, without further ado ...
Mark M.: Here in the Appalachians we have very dense crystalline rock…
eklemetti | June 14, 2009
Mt. Saint Helens in Washington state, USA
I'm back from my sojourn to New England and its time to play catch up. First things first!
There has been a lot of chatter in my inbox and on the comments here at Eruptions about the study/press release from Graham Hill's research group talking about the potential for a supervolcano forming at Mt. Saint Helens. This study (presented at the AGU Spring Meeting) was based on a magnetotelluric study of the area around (and below) Saint Helens. For those of you unfamiliar with magnetotellurics, it uses instruments that measure the magnetism and electrical…
eklemetti | April 15, 2009Busy day so I probably won't get to update much as we're busy hosting Dr. Charlie Bacon, geologist for the USGS, here at UC Davis today. Dr. Bacon has written some seminal papers in his career and is probably the foremost authority of the evolution of Crater Lake/Mt. Mazama (speaking of which, >a new geologic map for the Park was recently released) and the caldera-forming eruption. He's also a really nice guy.
If you want to read some of his papers, you might try these:
Bacon, C.R., Implications of silicic vent patterns for the presence of large crustal magma chambers, in: D.P. Hill, R.A…
eklemetti | March 27, 2009
Back in a former life, I was really into radio and music. Such an existence calls for many lists of rankings: "Best albums of 2004", "All time greatest soul singers", "Worst album covers of the 1980s". And, although I love a list as much as the next person, I tend to find lists appalling. Why? Well, mostly because no "Top list" of anything is accurate, and even worse, most of the time they're put together to generate controversy. "Wait until they see I listed Wade Boggs as the best third basemen in history!" You know, that sort of thing.
Anyway, much to my surprise (chagrin?), I recently an…
eklemetti | August 30, 2008
I am back from my trek through the Oregon and California Cascades - including stops at Lassen Peak/Chaos Crags, Hood, Three Sisters and Crater Lake (an added bonus). I'll try to catch up on the volcano news I've missed and post on anything exciting that happened soon, but otherwise I'll be posting new news as it occurs.
In the meantime, here's a picture I took of Rock Mesa (foreground) and South Sister (background) taken from the Pacific Crest Trail. Rock Mesa is a ~2,700 year old rhyolite flow that appears to have erupted multiple pumices and has some impressive flow banding of the rhyolite…
eklemetti | July 24, 2008
I am beginning to feel like a broken record, but the latest reports from Chile indicate that the ongoing eruption at Chaiten is ramping back up again, almost 3 months after the initial eruption began. As usual, the nitty-gritty details are limited, but reports of increased ash emissions and seismic activity are heralding this increase in activity.
For certain, Chaiten is one of the most important eruptions in any of our lifetimes. This is really not because of the amount of material that has been erupted (although when all is said and done, it will be a significant volume), but rather for…
eklemetti | May 29, 2008
The Oregonian reports on the on-going desire to develop geothermal power in the Oregon and California Cascades and backarc. There have been attempted (or at least exploration) to develop geothermal power at Newberry Volcano, Crater Lake and Medicine Lake, but none have ever panned out. Well, it seems like this time it might happen, and I, for one, think it is a good idea. Of course, there are a lot of folks who don't want a geothermal plant anywhere near Newberry, especially with its National Monument designation, but one of these days we'll have to choose between that and higher energy…
eklemetti | May 12, 2008
I've been trying to keep up with the Chaiten eruption in Chile, but the news is just beginning to sound like a broken record: eruption continues, ash falls, don't know much else. However, it does sound like Chile is being realistic about people's chances of moving back to the town of Chaiten - 10 km from the vent(s) - in the near future ... and those chances are zero to none. This doesn't entirely surprise me. If the town isn't already buried, when the pyroclastic flows do start, whether they be from the collapse of the the eruptive column or from the vents themselves, the town will be…
eklemetti | May 9, 2008
This marks a full week of eruption at Chaiten and the volcano shows no signs of abating.
You have to feel for Luis Lara. He is apparently the pointman for the SERNAGEOMIN in regards to this eruption and really, I think its anybody's guess what might happen next. Heck, we haven't seen many eruptions of this scale - and this out-of-the-blue - since the birth of modern volcanology, so we're testing a lot of hypotheses now. What Dr. Lara says is that the eruption is still going strong, lava flows seem to be occurring at/near the vent but not spilling out of the caldera, the two vents have…
eklemetti | May 2, 2008
The big eruption news today is an unexpected eruption in southern Chile. In fact, it is so unexpected that depending on when and where you read about it, you might get a different answer to what volcano is doing the eruption. What we do know at this point is an eruptive column has been spotted by people on the ground and the Washington VAAC, with estimates of an eruptive column height of between 35-55,000 feet. In other words: pretty darn sizeable. Ash is also coming down in town to the east of the eruption in Argentina. Now it seems that Chilean officials say Volcan Chaiten is the culprit…