Among the largest and most famous volcanoes on our planet is Mauna Loa . It is one of four volcanoes located in the Hawaiian Islands. Its name means "long mountain" in Hawaiian. Given its interesting characteristics and enormous size, it is considered the largest volcano on Earth. However, it is only the largest in terms of area and volume, as other volcanoes, such as Mauna Kea, are taller.
In this article we are going to tell you all the characteristics, eruptions, formation and curiosities of the Mauna Loa volcano.
Key features
Some of the stories surrounding this type of volcano come from the ancient Hawaiians. These people considered this type of volcano sacred. It is considered the largest volcano on Earth, with a surface area of approximately 5271 square kilometers and a width of about 120 kilometers. Due to its immense size, it covers almost half of the island of Hawaii. To learn more about this topic, you can consult the article on the world's largest volcanoes.
It is not only a large volcano but also a tall one. Although other volcanoes belong to the same volcanic network surrounding the Hawaiian Islands, this is one of the largest. It stands approximately 4170 meters above sea level. These dimensions, combined with its surface area and width, result in a total volume of about 80.000 cubic kilometers. Therefore, it is the largest volcano on Earth in terms of both area and volume.
It is famous for being a shield volcano with unique characteristics. It has continuous flows of volcanic ash and turbidity emanating from past eruptions. It is considered one of the most active volcanoes on Earth. Since its formation, it has experienced almost continuous, though not particularly powerful, eruptions. Its activity, along with its proximity to human settlements, has led to its inclusion in the Volcanoes of the Decade project , making it the subject of ongoing research. Thanks to this research, a wealth of information is now available about it.
It has a dome shape and its name comes from a caldera called Mokuʻāweoweo. This caldera is 183 meters deep. It has four subsidence craters formed by the collapse of the surface above a void chamber. The craters are named: Lua Hohonu, Lua Hou, Lua Poholo, and South Pit. The first two are located southwest of the caldera.
Formation of the Mauna Loa volcano
We know that this volcano is the second youngest in the Hawaiian Islands group. We know that these islands were created by tectonic plate movement. Specifically, it was caused by the movement of the Pacific Plate over a hotspot. This occurred approximately 30 million years ago during the Oligocene epoch.
Mauna Loa began as an underwater volcano approximately 600.000 to 1 million years ago. However, it's not known for certain if this information is entirely accurate. It may have formed slightly earlier or later than this timeframe. What is known is that it has had continuous and prolonged eruptions, causing the lava to solidify and eventually emerge from the ocean floor. It rose above the oceans approximately 400.000 years ago, although its growth rate has been slowing down for the last 100.000 years. For more information on this type of formation, you can read about the different types of volcanoes.
Records show that volcanic activity was much more intense during the early stages of Mauna Loa's history. As it has aged, it has covered a much larger area, but its growth has slowed. The fluid lava of Mauna Loa has allowed a large area to form around its crater. This is characteristic of shield volcanoes, which create a large plateau around themselves.
In addition, one of the fundamental aspects in the formation of Mauna Loa was the pressure of the water on this type of volcano. And it is that when developing underwater, it is known that the water pressure prevents them from acquiring a lot of height. Once the tip reaches the surface of the ocean, they are relieved of the water pressure. It is then when they are able to generate violent volcanic eruptions to experience new stages of growth. Mauna Loa's biggest growth stage since its formation was to reach the ocean surface. However, it is known that today this volcano is still in the formation stage of the classic shield volcano.
Mauna Loa eruptions
Currently there is no record of the eruptions that occurred before the arrival of Europeans in this area. However, there are numerous scientific studies that identify a fairly long history of eruptions. As we have mentioned before, it is more focused on more progressive and less intense eruptions. It is thought that the first eruption dates back a million years and since then various eruption events were those that caused it to obtain a greater surface, volume and height.
It is known that 98% of the volcano's surface is composed of lava ejected from the vent approximately 10.000 years ago. This makes it one of the youngest volcanoes in the Hawaiian volcanic chain. The Smithsonian Institution's Global Volcanology Program monitors the eruptions and has recorded at least 109 confirmed eruptions. The first eruption occurred in 1843, and since then, it has ejected material about 35 times. It's worth noting again that Mauna Loa is known for being active, but not particularly intense. In short, Mauna Loa erupts roughly every six years.
I hope that with this information you can learn more about the Mauna Loa volcano.