Why are volcanoes special?
Updated: Jan 24, 2020
Volcanoes are amongst the oldest things in existence on our planet. It is often described as a vent or hole in the ground, which spews out molten materials out into the earth’s surface. Over time, the expelled materials accumulate around the vent, forming small hills or large mountains. Volcanoes come in different shapes and sizes, of which the title for the biggest has been debated in the last decade. Mauna Loa[1], one of the volcanoes that form the Hawaiian island chain, used to be regarded as the biggest volcano on Earth until a group of researchers uncovered another shield volcano, submerged under the pacific ocean off the coast of Japan. Known as Tamu Massif, this giant submarine volcano covers an area of 120,000 square miles, and not only trumps Mauna Loa in surface area, but it took the crown for the biggest volcano in our stellar neighborhood. But in recent times, Mauna Loa seems to have reclaimed its throne since Tamu Massif does not fit into the definition of a proper volcano anymore.
So, since Tamu Massif is not what we think it was, then what exactly is the biggest of them all? For that, we have to leave our planet and venture not far, but to our neighbor, we will soon visit. The Martian giant known as Olympus Mons[2] is so large that it sticks out through the Martian atmosphere. With a peak height of about 25 km, it is the tallest, and with a volume which is 100 times more than that of Mauna Loa, it is also the largest as well. Simply put, this one is mighty as they come.
As long as we are up amongst the planets, talking volcanoes, let's shout out to the most volcanically active place known to humankind. Io[3], Jupiter's closest moon is in a very tricky region, experiencing strong tidal tugs from Jupiter and two of its other moons, namely Europa and Ganymede. This tidal force[4] imparts enormous heat within Io and renders most of its subsurface crust molten, and this molten liquid constantly escapes to the surface of Io, forming volcanoes, and in the process, making it one of the most dangerous places in the solar system.
Why are volcanoes extraordinary?
Today, about 80 percent[5] of Earth’s surface, above and below sea level, is volcanic. But once volcanoes dominated our planet, and it was nowhere near the shade of blue, which it is today. It was a barren wasteland, a morbid place for life. And though most rocky planets possess volcanoes, the earthly volcanoes supposedly did something in the early childhood of the solar system, which others couldn’t. It is thought that the primordial volcanoes had a role to play in the blueing of the Earth. Scientists suggest that the gaseous emissions[6] from the volcanic vents, especially the trapped water in underground rocks, vaporized into the atmosphere as water vapor, producing the earliest rains, and over hundreds of millions of years, forming the oceans, which was imperative to early life.
How did volcanoes shape the planet?
The pyroclastic clouds, as well as lava, can deposit volcanic matter across large distances during volcanic eruptions. And on our planet, over eons, numerous volcanic eruptions produced the landscapes like mountains, plains, plateaus, islands, and many other incredible structures. The entire chain of Hawaiian islands was formed by volcanic hotspots in the middle of the Pacific tectonic plate. A portion of the soil on Earth consists of volcanic matter, which got piled up over time, and is rich in elements like nitrogen and sulfur, which are essential for plants. Agriculture, which is thought to be the driving force of civilizations, owes a great deal to these menacing wonders.
In volcanic islands like Iceland, the magma beneath the earth’s surface is used to produce renewable energy. Currently, geothermal power[7] accounts for 25% of the country’s total energy production. But not all lands around the world are geothermally active, and therefore, such an energy generation has boundaries at the moment.
Volcanoes and weather
The Tambora volcanic eruption of 1815 was in the record books for a variety of reasons. It was the most powerful volcanic eruption ever recorded by us, with a volcanic explosivity index of 7. But it also caused the global temperature to drop by around 3 degrees Celsius. The weather patterns which followed went haywire, and 1816 came to be known as the 'year without a summer'.
The volcanic ash contains gases like sulfur dioxide, which can travel to the upper levels of the atmosphere and combine with water to form sulfuric acid. Sulfuric acid, along with other aerosols emitted from volcanoes, acts as sunlight-reflectors[8]. This results in a drop in temperature, which is often referred to as volcanic winter. Throughout the history of the planet, several supervolcanoes caused volcanic winters, which shaped the planet’s climate.
To our knowledge, life doesn't exist outside the blue marble, but the presence of volcanoes is thought to be very common on cosmic bodies. So, the billion-dollar question is, could there be similar life-harboring stories of volcanoes spread across our night sky? This is one of the things that planetary scientists at NASA [9] are studying these days, as they travel to volcanically active regions on our planet for a window into uncovering the mysteries of the universe.
Read more from sources
[1]. Wikipedia contributors. (2019, August 18). Mauna Loa. In Wikipedia, The Free Encyclopedia. Retrieved 16:38, September 8, 2019, from https://en.wikipedia.org/w/index.php?title=Mauna_Loa&oldid=911421141
[2]. NASA. Mars Atlas; Olympus Mons. In NASA's Mars Exploration Program. Retrieved Sep 8, 2019, from https://mars.jpl.nasa.gov/gallery/atlas/olympus-mons.html
[3], [4]. NASA. (Page Updated: April 25, 2019). Io. In NASA science solar system exploration. Retrieved Sep 8, 2019, from https://solarsystem.nasa.gov/moons/jupiter-moons/io/in-depth/#how_io_got_its_name_otp
[5], [6]. U.S. Geological Survey, How much of the Earth is volcanic?, accessed Sep 8, 2019 at https://www.usgs.gov/faqs/how-much-earth-volcanic?qt-news_science_products=0#qt-news_science_products
[7]. Orkustofnun: National Energy Authority, Geothermal. accessed Sep 8, 2019 at https://nea.is/geothermal/
[8]. Lonnie Shekhtman, NASA's Goddard Space Flight Center . (Nov. 13, 2018, last updated Dec. 4, 2018). How Earth Volcanoes Offer a Window into the Evolution of Life and the Solar System. Retrieved Sep 8, 2019, from https://www.nasa.gov/feature/goddard/2018/how-earth-volcanoes-offer-a-window-into-the-evolution-of-life-and-the-solar-system
Stock images used:
Lava flow: https://unsplash.com/@ldandersen
Comments