Yellowstone volcano TREMORS: Seismometers detect 'seismic ENERGY' prompting need for study

More than 50 seismic trackers around Yellowstone volcano’s biggest lake have recorded evidence of tremors known as microseism. The Yellowstone discovery comes off the back of a study examining the presence of tremors in great lakes around the globe. Microseism is a faint shake of the Earth associated with the interaction of ocean waves and the seabed. In Yellowstone, trackers have found evidence of microseism on a much smaller scale, at the 135.9 square miles (352.1 square km) Yellowstone Lake in Northwest US.

Jamie Farrell, chief seismologist at the Yellowstone Volcano Observatory, said the study funded by the National Science Foundation, has found the most likely source of the tremors.

The geologist explained in the weekly Yellowstone Caldera Chronicles: “There are two ways that the ocean’s waves cause seismic shaking.

“The direct interaction of ocean waves and the solid ground near the shoreline – single frequency microseism – and the interaction of two sets of wave trains travelling in different directions in the open ocean – double frequency microseism.

“The double frequency microseism can be due to two storm systems and their associated wave trains, interacting in the open ocean, or caused by waves interacting with reflected waves near the coastline.

READ MORE: Is Yellowstone OVERDUE another super-eruption?

“Due to the size of the world’s oceans and the costs of deploying ocean-bottom seismometers, there are very few observations of the source of the oceanic microseism.”

In Yellowstone’s case, the seismic energy generated by Yellowstone Lake is the second, double-frequency type.

This type of seismicity is caused by so-called wave-wave interaction.

Further investigation into the seismic phenomenon can help geologists map the geyser basin beneath the lakebed of Yellowstone Lake.

However, scientists are still uncertain where exactly the microseism is located within Yellowstone Lake.

READ MORE: Yellowstone volcano – 84 EARTHQUAKES strike supervolcano park

Dr Farrell suggested there is a yet unexplored correlation between Yellowstone Lake’s waves and the ever-changing direction of the wind.

He said: “Future analysis of these seismic data will provide an opportunity to advance the understanding of the generation of microseismic energy as well as illuminate the robust hydrothermal system on the floor of Yellowstone Lake.

“In addition, since microseismic energy is only generated during warmer months when the lake is not frozen, we can use the permanent seismic network to record the date of when microseismic energy is generated – lake thaw – and the date where the microseismic energy ceases to exist – lake freeze – through time.

“A long-term record of these data can provide additional data related to the effects of climate change in the Yellowstone region.”

READ MORE: USGS predicts Yellowstone SUPER ERUPTION date

The microseismic discovery came in the wake of The University of Utah and the Woods Hole Oceanographic Institute deploying 40 land seismometers around Yellowstone Lake.

Additional measurements were made by four weather stations in the region and two wave gages in the lake.

The seismometer deployment was also made in conjunction with the HYDLAKE project, which deployed another 10 measuring instruments at the bottom of Yellowstone Lake.

Overall, scientists have found the microseism at Yellowstone takes around one second between two consecutive peaks as opposed to three to 20 seconds in the oceans.

source: express.co.uk