Volcanoes have been in the news a lot lately. We recently had a record breaking eruption in Tonga that was so intense that the blast wave crossed the globe at least four times and was heard as far away as Alaska. An eruption on La Palma in the Canary Islands destroyed thousands of structures and forced the evacuation of local residents for several months. For obvious reasons, most of the media focus has been on the destructive aspect of volcanism, but there is so much more to explore and appreciate. Here are ten reasons why volcanoes are awesome:
1. They create good farming soil.
Volcanic soils are some of the most fertile in the world, which is why so many people live close to volcanoes in the first place. Famous destroyed cities such as Pompeii and Saint Pierre were located so close to their mountains to take advantage of the fertile soils to grow olives and sugar cane, respectively. Volcanic soils also support the wine industry of the Napa Valley in California, and the Latin American coffee industry. The volcano in this week's picture is Mayon in the Philippines, also known for its fertile farming soils.
2. They create new land.
This was demonstrated in Hawaii in 2018 and, most recently, at La Palma in the Canary Islands. Lava flows create deltas at the edge of existing land, altering the topography and extending the coast. Ash flows and avalanches can also create land in this way, though their process is much more violent. Volcanic islands emerging from the ocean have provided new habitat for various colonizing plant and animal species. Until it’s 2018 collapse, Anak Krakatau was a laboratory for such observations, and Surtsey, an Icelandic island that formed in the 1960s, is still a subject of study.
3. They help regulate Earth’s climate.
Volcanoes produce large amounts of gas, especially during eruptions. One of the most prominent for our discussion is sulfur dioxide, which is known to have an atmospheric cooling effect. Though the apocalyptic volcanic winter theories touted by the media have mostly been disproven, cooling effects from eruptions can be quite significant if given the right conditions, particularly the location of the eruption, the size of the eruption, and the amount of sulfur dioxide said eruption releases. A significant event occurred after the Tambora eruption of 1815, which led to what was described as “the year without summer.” (Google this. It’s very interesting!) Less severe cooling was observed following the eruptions of Pinatubo in 1991 and El Chichon in 1982.
4. They are a vital part of Earth’s massive recycling system.
Whether they are along subduction zones, in spreading zones, or over hot spots, volcanoes are ruled by plate tectonics. Hot spot volcanoes move along with the plate that passes over the plume that feeds them. Arc volcanoes are formed over areas where plates converge, and other volcanoes form over divergent areas as the plates move apart. I could go on forever with the usual lecture you’d find in volcano books, but I will just summarize here. Essentially, the process of subduction draws old crust and other junk into the planet, where it’s processed and melted down. The material eventually rises at volcanic arcs, where it is erupted. These erupted products eventually become part of the recycling process once again.
5. They help us construct timelines of Earth’s history.
Lava flows and ash layers are used to determine the ages of various ancient things. This includes fossils, other eruptions and geologic events, archeological sites, lake and ice core samples, and ancient forests, to name a few. If the age of a certain volcanic layer is known (through various dating techniques I won’t discuss here), an age for the things it covers or underlies can be determined. In the Pacific Northwest, the prominent Mazama ash layer is used for this purpose, as are several significant layers formed by Mount Saint Helens. I once assisted a paleoecologist who determined the age of a lake based on the existence of a Glacier Peak ash layer, and later we used a Saint Helens layer to find the age of a wildfire at Mount Rainier.
6. They make great tourist attractions.
People love visiting volcanoes for various reasons. Obviously eruptions are spectacular and attract a lot of attention, but volcanoes are also responsible for other tamer forms of recreation. There are ski resorts, mountain climbing sites, hot springs, and the pure scenic beauty. Volcano tourism is big business and can support local economies. The recent eruption in Iceland attracted thousands of tourists from all over the world. In the United States, volcano tourism is also big, especially in Hawaii and the Pacific Northwest. People flock to see eruptions on the Big Island, or to explore the volcano-torn wilderness at Mount Saint Helens, or the spectacular scenery and nature at Crater Lake and Mount Rainier.
7. Their eruptions can be seen from space.
Satellite technology has allowed us to study volcanoes from a whole new perspective. As we saw with the recent Tonga eruption, large ash clouds are easily picked up by today’s technology, and there are even satellites capable of reading their sulfur dioxide content. But ash eruptions are not the only volcanic phenomena detected this way. Specialized satellites pick up the heat from lava flows and give us an idea of the extent of a lava eruption. Once a sensor aboard a satellite array picked up the heat trapped underneath the Chaiten volcano years before it finally erupted.
8. The largest mountain in the world is a volcano.
No, the largest mountain is not Everest. It’s not even the tallest. For many years that distinction went to Mauna Loa on the Big Island of Hawaii. When measured from its base below the ocean, this massive volcano is far bigger than Everest in every respect. According to the USGS, the volcano is 10.5 miles from base to summit, making it the largest active volcano on the planet. But it turns out there is a volcano even bigger than Mauna Loa, though it is almost completely submerged under the ocean. This volcano is twice as big as Mauna Loa, though it is no longer active, so she still holds the record place as largest active volcano.
9. They can serve as energy sources.
Volcanoes are major sources of heat, as well as water. The steam from this water can be harnessed and used to turn turbines, which produce fairly clean electricity. This method is referred to as geothermal power. Though it’s renewability and environmental impact is still disputed, this method of electrical power generation is growing around the world. The United States is a leading producer of geothermal power, but it is the primary source of energy for the nation of Iceland, which is essentially a giant volcanic island.
10. They create important minerals.
Heat and other volcanic processes are associated with the precipitation and formation of various minerals and metals. This includes gold, silver, copper, lithium, sulfur, and some rare earth metals. Most of these are found in old geothermal areas where hot waters circulated and concentrated the minerals, and most of those were created by ancient volcanoes. This process brought out the metals now found in California’s Gold Country, and it continues to this day in other locations. Interestingly enough, there is a volcano in Colombia, Galeras, that spews microscopic gold flakes in its ash. Metal spewing has also happened at Mount Rainier, where I found large amounts of copper and pyrite in ash deposits from a lake core. Someday these volcanoes will be extinct and their internal metal deposits will be exposed.
There are a myriad of other interesting things about volcanoes, way too many for me to include in this brief blog post. Already this year we have seen some interesting performances from our magmatic neighbors. Perhaps someday I will do another list about volcanic eruptions and talk about some of these. Today, however, I focused on interesting things about volcanoes in general and how they can benefit us all. Stay tuned for more posts of awesome things in the future!