Since dawn of civilization, mankind has ever been awestruck, equally fascinated and horrified, by the raw and ferocious power of volcanoes. These explosive formations have shaped cultures, wiped out civilizations, and remolded the face of earth on numerous occasions. But how well do we really understand these fiery outlets of Earth’s inner energy? In this article, we dive into the world of these remarkable natural structures, honing in on the difference between a volcano and a supervolcano, bringing greater understanding to what constitutes these variable volcanoes, and shedding light on some of the Earth's biggest volcanic eruptions.
Understanding Volcanoes
A volcano is a rupture in the Earth's crust that allows molten rock, debris, and gases to escape from beneath the surface. This often explosive emission results from the movement of tectonic plates. Volcanoes can take several forms, including shield volcanoes, composite volcanoes, and cinder cones, each of which possess unique characteristics and behaviors.
There are roughly 1,500 active volcanoes on Earth. This does not include the estimated millions that exist beneath the ocean. The location of these marvels of nature is not random, in fact, most are found along tectonic plate boundaries. The "Ring of Fire", an area located in the basin of the Pacific Ocean, is home to most of the world's active volcanoes. Understanding volcanoes not only involves knowledge about their formation or types but also requires comprehension of their impact both environmentally and societally. Volcanoes have the power to influence climate, shape the landscape, and even cause widespread devastation.
The Difference between A Volcano and A Supervolcano
Now that we have a basic understanding of volcanoes, it's time to compare them to their more colossal kin: supervolcanoes. So, what exactly is the difference between a volcano and a supervolcano? The differences, as you might suspect, are quite significant.
The term 'supervolcano' is used to describe a volcano that has the potential to cause devastation on a global scale. These are not simply bigger versions of regular volcanoes; the difference in scale is mind-boggling. A supervolcano can release over 1,000 cubic kilometers of volcanic material in a single eruption, that’s over a thousand times more powerful than a typical volcanic eruption. There are only a handful of recognized supervolcanoes on Earth. These include the Yellowstone caldera in the United States, the Long Valley caldera in California, and Toba in Indonesia.
The Earth's Biggest Volcanic Eruptions
While the cataclysmic power of supervolcanoes is unrivaled, regular volcanoes too, have caused their share of remarkable eruptions. Delving into the biggest volcanic eruptions in earth's history gives us a humbling perspective on the raw and unbridled power Mother Nature commands.
Mount Tambora in Indonesia takes the spot for the most powerful volcanic eruption in recorded history. The eruption that occurred in 1815 was so powerful, it instantly killed over 71,000 people, and the resultant 'volcanic winter' caused widespread famine across the globe. Yet, even this event pales in comparison to supposed past supervolcano eruptions which may have released energy over a thousand times greater.
The difference between a volcano and a supervolcano lies in their respective magnitudes of eruption. A volcano, according to the United States Geological Survey (USGS), is a vent in Earth's surface, often in the form of a mountain, where molten rock (magma) and gases from the Earth's interior are expelled. By contrast, a supervolcano denotes a particular kind of volcanic structure - a large caldera - and refers to eruptions that produce at least 240 cubic miles (1,000 cubic kilometers) of volcanic material. To help visualize this scale, the 1980 eruption of Mount St. Helens in Washington state produced just over 0.05 cubic miles (0.2 cubic kilometers) of material. The element of magnitude is what truly distinguishes the two.
In terms of variety, there are many kinds of volcanoes, including stratovolcanoes, shield volcanoes, and cinder cones, and not all eruptions are the same. Some result in an explosive blast while others produce a steady, slow flow of lava. Supervolcanoes, on the other hand, are characterized by explosive eruptions so violent that they cause colossal craters, or calderas, to form. These massive depressions are typically several miles to several dozens of miles wide.
Major Eruptions
The biggest eruption in recorded human history was from a supervolcano - the eruption of Mount Tambora in Indonesia in 1815. It resulted in a year without a summer in 1816 due to the large amount of sulfur dioxide released into the atmosphere, which reflected sunlight away from the Earth and caused global temperatures to decrease. Crop failures and livestock deaths led to the worst famine of the 19th century.
In contrast, typical volcanic eruptions do have a significant impact on the environment and local communities but are less likely to have global implications. For instance, when Mount St. Helens erupted in 1980, it was a catastrophic event that resulted in 57 fatalities and significant local environmental damage. However, it didn't alter global weather patterns as supervolcano eruptions are capable of doing.
Frequency of Eruptions
Regular volcanic eruptions occur around the world on a daily basis. According to the Smithsonian Institution's Global Volcanism Program, there are around 20 volcanoes erupting on any given day. Supervolcano eruptions, however, are less common. The USGS points out that the probability of a supervolcanic eruption in any given century or millennium is exceedly low. The last known supervolcano eruption occurred about 27,000 years ago in New Zealand.
The Future of Supervolcanoes
We can't predict with absolute certainty when the next supervolcano eruption will occur. However, scientists continually monitor supervolcanoes, such as the one beneath Yellowstone National Park in the United States, using a variety of techniques including seismometers and satellites. This ongoing vigilance aids in recognizing warning signs that might prelude a major eruption. While such a cataclysmic event is highly unlikely, knowing and understanding the power of these forces helps us to stay prepared and mitigate risks.
Both volcanoes and supervolcanoes offer fascinating insight into the dynamic, ongoing processes that shape our planet. From providing fertile soils to influencing global climates, these geological wonders continue to shape life on Earth in myriad ways.