Episode 191 S5-28
Preparing for a Volcanic Eruption
Dark Days in Denver Ch 28
Active volcanoes appear the most over subduction zones. These are places where two continental plates come together. The Ring of Fire is an area that lines the continents on the exterior of the Pacific Ocean and is a particularly volatile area. The constant plate movement ensures a multitude of earthquakes and volcanic activity will happen in the countries surrounding this area. Earthquakes often accompany magma movement and the resulting volcanic eruptions.
Volcanoes can have a significant effect on global weather temperatures. In the most recent history, the 1991 eruption of Mount Pinatubo caused global cooling on a small scale for a couple of years. Another historical example would be the 1815 eruption of Tambora in Indonesia. The volcanic eruption caused the globe to experience "the year without a summer." Around the world, there were massive crop failures, and Mary Shelley held up in a home to hide from the weather. During her time there she wrote the famous novel, Frankenstein.
Big eruptions like the 1883 eruption of Krakatoa can cause massive damage and have severe global consequences. However, most volcanoes take time to recharge or rebuild. This particular volcano has been pretty much continuously erupting since 1883. A new cone grew, and the mountain became known as Anak Krakatau or "Child of Krakatoa." In December of 2018, the cone fell apart and caused a massive tsunami. The lava was exposed to the sea, fueling an explosive event.
The last supervolcanic eruption happened in 1238 in Indonesia. Scientists like Michael identify potential places where these types of events could occur and trying to figure out when and how big the eruption will be.
There are a variety of ways to monitor volcanoes. Scientist use holes bored into the earth with seismic equipment inside but they are expensive and logistically challenging. The easiest way to track activity is with surface mounted GPS stations. These units measure how much the ground is moving or shaking. The boreholes provide a new dimension to the readings and allow for a different view of the earthquake. The surface mounted units can be affected by air blasts and surface noise.
In California, a sleeping giant exists. Although Yellowstone receives much more attention, the Long Valley Caldera is a super volcano. It erupted 780,000 years ago in a big way and has had a few smaller eruptions since then. There is a chain of volcanoes, known as the Mono Inyo Craters, which have also had small explosions. This series of volcanoes is of interest thought because they are relatively young and likely to erupt again.
To develop a proper family preparation plan, you have to understand the hazard in your area. Threats may come from ash flows rushing on the ground, hot gas, volcanic mudflows or lahars, earthquakes, or lava flows. You have to know the volcano and the hazard map to depict what potential risks you are facing. Some volcanoes like Mount Rainier will typically not produce much ash, but it will generate mudflows so an individual in the danger zone should have a planned route to higher ground. Some volcanoes, like the one that erupted in Hawaii, have fast moving red hot lava while others, like Mount St. Helens have very slow flowing lava that erupts in solidified columns.
To find out if you are in danger of a volcanic threat, you can check out: https://volcanoes.usgs.gov Click on the observatory link at the top right and then select the state of interest. Then you can choose the hazard map and report that corresponds to your location. The civil defense agencies also have evacuation plans that you can obtain.
Your survival kit should take into account that there is a possibility of earthquakes disrupting public services. It would help if you had a couple of weeks worth of food and water to prepare for such a contingency. The gas from a volcano tends to dissipate rapidly, but if you have respiratory problems or are close to the source, you may consider a gas mask. If you anticipate ash fall you should have a particulate mask or at the very least a hanker chief or t-shirt to cover your face.
The supervolcano known as Yellowstone is still considered a massive threat because it has generated many gigantic eruptions in the past. One occurred 2.1 million years ago, one was 1.3 million years ago, and one was 631,000 years ago. It is generally very unusual for one volcano to have repeated super-eruptions. This activity indicates that Yellowstone receives a constant magma supply. It is a hot spot or melting anomaly on the earth's mantle.
The media and Hollywood production companies have also popularized the threat that exists at Yellowstone.
Also, Yellowstone is not a regional threat. Usually, individuals three states away would not be concerned about ash fall from a volcano there, but Yellowstone can produce such an eruption that its fallout would affect North America and change the weather on the entire globe. The exact amounts of ash falling across the country would depend on the size of the eruption, the concentration of ash in the air and the wind speed and direction. However, it is rare for Yellowstone to have a super-eruption. More often it has lava flows, which produce a lot less ash.
Yellowstone has the highest concentration of geysers and hot springs in the world. Three things make Yellowstone geologically active: heat (from the magma), water (it's the highest point in the Rockies) and geology (its just right for the water to percolate next to the heat source). Things are always on the move in Yellowstone. In 2003 there was a new heating event in the Norse geyser, and in September of 2018, a new feature formed right next to the boardwalk. The temperature can vary significantly in a small area.
Yellowstone was the first US national park, and its beauty attracts many. One thing that is always a constant at Yellowstone is change. In 2018 Ear Spring Geyser erupted for the first time in many years. These springs are full of minerals that can clog the system. The removal of the clog, caused an eruption, blowing out tons of trash, including a car axle, a pacifier from the 1930s, cinderblocks and lots of coins. The hot springs at Yellowstone are not for bathing! The edges of these pools are a thin crust that can crack easily. If you fall into that boiling water, your body may not even be recoverable.
Currently, there is no indication of abnormal change at Yellowstone. Earthquakes happen all the time there. One year, scientists located a swarm of 2400 quakes. Others occurred that were smaller and unreportable as well. This earthquake activity is cause for alarm for other volcanoes, but all the heat and water at Yellowstone make it much more active. To cause concern, there would have to be an earthquake swarm of 10 thousand or more with massive uplift happening at the same time. The last time lava flowed at Yellowstone was 70,000 years ago. Mount St. Helens didn't even exist at that time.
Your geographic location is a good starting point for accessing the threat of any hazard. Find out what types of risks exist in your area and plan accordingly.
Ring of Fire
Long Valley Caldera
Featured Quote From Today's Chapter:
"Your life is over. You are now the property of the Federal Republic of America."