4.4 Magnitude quake hits Yellowstone - Tremors increasing in frequency

Yesterday, June 15 2017 at 18:48 MDT, a magnitude 4.4 earthquake struck at Yellowstone National Park. This is one of the largest to strike since March of 2014 when a magnitude 4.8 occrurred.

On average, approximately 1,000 to 3,000 earthquakes take place each year in the Yellowstone area. The majorities are too small to be felt, but a few like the one that occurred yesterday, 6/15/17 was felt.

The University of Utah listed it as a magnitude 4.4 on the Richter scale. Since then, there have been several more tremors that are still measuring slightly above previous magnitude averages.

                           Map of calderas                                                                  Current locatio of tremors

There are three calderas. They lie over a a hotspot where light, hot, molten rock from the mantle rises toward the surface.

There have been three large volcanic eruptions in the past 2.1 million years. Each of Yellowstone’s explosive caldera-forming eruptions occurred when large volumes of “rhyolitic” magma accumulated at shallow levels in the Earth’s crust, as little as 3 miles (5 km) below the surface. This highly viscous (thick and sticky) magma, charged with dissolved gas, then moved upward, stressing the crust and generating earthquakes. As the magma neared the surface and pressure decreased, the expanding gas caused violent explosions.

The location of one of the largest earthquakes to occur as compared to the location of the current tremor swarm

As of 6/16/2017 at noon central time, the average depth of the past 18 tremors is 8.55 Km or 5.31 miles. It will be interesting to note whether or not the tremor depths decrease over the next few days. If so, the probability of an eruption occurring significantly increases.

Stay tuned for more follow ups.