Since late summer 2013, the Yellowstone GPS network has tracked a small " ground deformation episode" in north-central Yellowstone National Park.
During the past five months, the NRWY GPS station has recorded about 3.5 cm (1.4 in) of uplift (the ground is rising) and about 1 cm (0.4 in) of southeastward ground movement, relative to a stable reference station north of the Park.
Measurements from other GPS stations in northern Yellowstone show smaller displacements, forming a circular pattern of deformation (circular - as in the round mouth of a volcano) consistent with a minor pressurization (building-up underground), about 6 to 10 km (4-6 miles) deep, near Norris Junction.
What has scientists very concerned is that Yellowstone has suddenly begun emitting massive amounts of Helium-4. Helium-4 seems to be the predictor of activity, as proved with other volcanos.
For instance, as the volcanic island of El Hierro, the smallest of Spain's Canary Islands, rumbled and groaned over the course of seven months in 2011 and 2012, gases silently percolated up through the island's soil and groundwater.
Eventually, a spectacular plume appeared off the southern coast of the island, a sign that El Hierro volcano, an underwater volcano just offshore, had finally erupted.
[link to www.livescience.com]
The team's analyses show that, as the El Hierro volcano began to stir, the crust fractured and helium, mostly from the mantle, flowed to the surface. As the actual eruption began, gas flow at the surface increased dramatically, and gas pressure beneath the island dropped. Then as seismic activity at El Hierro picked up again, the crust fractured and deformed extensively, and helium-4 became a larger component of the total helium released on the island.
Looking at the past ratios of helium at Yellowstone 1978:
Helium isotope ratios (³He/4He) in Lassen Park and Yellowstone Park volcanic gases show large ³He enrichments relative to atmospheric and crustal helium indicating the presence of a dominant mantle-helium component
[link to onlinelibrary.wiley.com]
Study released today on Yellowstone helium:
[link to www.nature.com]
The scientists who revealed today's information report the quantity of helium-4 in Yellowstone's gas emissions is hundreds to thousands of times greater than it should be - a sign that the crust is releasing its ancient stores of the rare isotope, the researchers said."However, much of the helium emitted from this region is actually radiogenic helium-4 produced within the crust by decay of uranium and thorium. Today's report shows by combining gas emission rates with chemistry and isotopic analyses, that crustal helium-4 emission rates from Yellowstone exceed (by orders of magnitude) any conceivable rate of generation within the crust." This means the Helium -4 is coming from very far beneath the ground, a clear signal that something big is happening that hasn't happened in Yellowstone in our lifetime.
In areas where there is little groundwater or movement in Earth's crust, helium-4 can remain trapped and build up over time. This is especially true at Yellowstone, where inactive rocks, or what geologists call "craton," have been estimated to be 2.5 billion years old. (The park is located primarily in Wyoming.) Things began to change roughly 2 million years ago, however, when hot magma intruded on the crustal system from below and triggered several enormous volcanic eruptions, the most recent about 640,000 years ago.
For scientists, there are important implications to the recent developments at Yellowstone. Helium and other noble gases are used to estimate groundwater residence times - for example, scientists assume that the more helium-4 present in water, the longer that water has been sitting in the rocks surrounding it.
But the study of helium at Yellowstone shows that some of these assumptions - specifically helium-4 produced by the steady decay of elements found only within the rocks and sediments of the local aquifer - aren't quite right. Helium can suddenly come into a system from unexpected places - a pocket of ancient rock, for instance, or a magma source - so the dates in past calculations, particularly those from aquifers in volcanic regions or near earthquake faults, might be way off because of that extra helium. Scientists, though, are used to dealing with new data that changes long-held theories; that's the nature of science, after all.
One of the earthquakes in the US this week, at just M3.6, occurred close to Yellowstone crater, on 11 February. The area, which overlies a hotspot (where hot magma from the mantle rises to the surface) is characterized by frequent earth tremors, which often occur in clusters (or 'swarms') such as those of 2004, 2009 and 2010. This one, however, was not merely a "tremor" it was a small quake.
Tectonically speaking, Yellowstone lies to the east of most of the major earthquake zones which characterize western North America and the earthquake swarms around Yellowstone are related to movements of the magma which lies beneath.
Residents of the Yellowstone area, however, probably wish researchers would just hurry up and figure out whether or not the supervolcano that's simmering below them and last erupted 640,000 years ago is going to blow again anytime soon.
[link to www.latimes.com]
The take aways from the above story can be found at PreppersWorldUSA.