Oregon Is Growing A Mystery Bulge

nedwolf writes "LiveScience is reporting that a 100 square mile bulge has been rising in Oregon. First observed from a satellite using a relatively new technology called 'radar interferometry', some believe this to be the formation of a new volcano. I think it's just happy to see me."

Comments

Super Volcano?

[silasthehobbit]

There's supposed to be one in Yellowstone Park (http://news.bbc.co.uk/2/hi/science/nature/4326987 .stm)which has been bulging for some time now. If this is indeed another one, then the fallout from Katrina is going to seem mild in comparison. -- silas

Re:Super Volcano?

[mrchaotica]

Yeah, that's what I first thought upon reading this, too, since 100 square miles sounds pretty darn big. Then I looked it up, and realized that the Yellowstone caldera is an order of magnitude bigger (28 * 47 = ~1316 square miles), and that only includes the actual part where magma comes out. In comparison, this 100 square mile figure includes the entire area of uplift.

Interesting. What can be done about it?

[eggstasy]

People write volumes about the possibility of a meteor impact, and what could be done to prevent it, while ignoring the larger threat that lies beneath us.
If we knew a giant volcano was likely to form somewhere, what could possibly be done about it?
Aside from moving people out of harm's way, would it be possible to, say, drill a bunch of holes in it and relieve pressure?
(This is a very interesting read, if you haven't stumbled across it - http://en.wikipedia.org/wiki/Supervolcano)

New measurement technique != new geology

[Analogy Man]

They are now able to detect this swelling...how do we know it isn't normal. Maybe the Earth's crust swells and ripples all the time and it is only 5% of this activity that manifests itself in earthquakes and volcanos.

Pretty cool either way though. If there is a correlation it could be very useful predictive data.

A relative of the Super Volcano at yellowstone?

[Anonymous Coward]

IF I recall a documentry I watched a few years ago correcly, then Yellowstone park is a giant super volcano, that many hundresds of thousnads or millions of years ago was much much further north (I forget which present day state), could this be a new super volcano forming in the same orginal area?

(rember if yellostone blows it's top, say bye bye to life in North America)

The fallout from Yellowstone...

[jd]

Well, you're assuming that all the ash will fall immediately out of the sky. Actual estimates predict that there'll be a significant ash fall up to 4,000 miles from the volcano, based on historic data.

Also, given the number of volcanos we've actually seen form (none), and given that vulcanology is not an exact science, it would be premature to assume that volcanos can't form rapidly. All we can really say is that the data implies that slow formation is by far the most common form.

What is needed, for an explosive volcanc eruption, is a massive buildup of pressure and a blockage such that the pressure cannot be released gradually. There is absolutely nothing to say that this could not happen in a new volcano, if the geology of the area is such that seeping to the surface is impossible.

Most regular explosive eruptions are caused by lava solidifying and blocking the throat of the volcano, followed by a massive rise in pressure that will destroy the blockage (and often part of the volcanic cone). Mount St. Helens was a good example of this. So was Krakatoa.

This only applies when the lava has a very high silica content, so that the lava flows poorly. In areas like Hawaii, where the lava is "thin" and runs relatively easily, you don't generally get many cones and those won't generally block often. This, in some ways, is worse because lava flows will be more common, cover a larger area and therefore be more destructive.

The plugs in highly viscous lava volcanos only form when there is a long period of dormacy. So, for example, Mount Vesuvius is unlikely to explode. The temperature remains high enough for plugs not to form. Mount Hood, on the other hand, has been dormant for a couple of hundred years. Not long enough to form a massive plug, but long enough that when it goes, it'll make Mount St. Helens look like a sunday school outing.

The (possibly active) volcanos on Mars may not have erupted in the past thousand years. The plug that will have formed in that time will be considerable, so the pressure required to blast it out must also be considerable. If any were to go off, it will likely destroy the entire cone, as per Krakatoa, and will create seismic shockwaves infinitely worse than those from the 26th December earthquake.

(In fact, it would be good to know if those volcanos are due to explode, as we could learn a lot about the interior of Mars from the shockwaves.)

Back to Earth, though - it depends on the forces required to cause the bulge detected. Igneous rock doesn't flex too easily. It also depends on the breaking point. If the rock is such that to cause a bulge of the size and height detected, energy comparable to a major volvanic eruption would be required, AND the rock will catastrophically fail on flexing beyond a critical point, THEN a sudden and major eruption is entirely possible.

The seismic data others have linked to indicate that this is NOT the case, that there is no major pressure buildup, and none of the earthquakes associated with such a buildup. Most likely, this is magma rising to the surface, much as it did in places like Dartmoor, England. No big deal, but will be a good source of granite in a few million years.

The important point, though, is that sudden explosive events CAN happen, that there is nothing impossible about them, that they will be confined to very specific physical and geological conditions, which means they'll be rare, but because they are possible, we should recognize and accept that fact. It is only by accepting it, and then investing in the physical sciences to better understand the geologic processes involved, that we'll be able to prevent volcanos being a threat in the future.

Ignorance and denial are the two biggest killers, when it comes to volcanos and earthquakes. The geological processes themselves are merely the blunt instruments of choice.