Mauna Loa

Volcanoes are of different types including dormant and active volcanoes. The dormant volcanoes are the ones that are not erupting whereas the active volcanoes are the ones that continue to erupt. Mauna Loa rises at an elevation of 13, 679 ft (4.169 m) and is the second-largest active volcano in the world. It is one of the five volcanoes that form the Island of Hawaii located in the United States. Mauna Loa means “long mountain” in Hawaiian and makes up nearly 51% of the Hawaiian Island. It rises from the bottom of the sea bed in the Pacific Ocean and rises at a height of 30, 000 feet from the sea level. The topic includes important information on the volcano and its past eruptions and formation. 

Structure and Description of Mauna Loa 

• An interesting fact about Mauna Loa is that it is the second-largest active volcano on Earth after Tamu Massif. It is located on the Pacific Ocean and rises from the sea bed.
• It is the largest subaerial volcano in both mass and volume at an elevation of 13, 679 ft from the sea level and a total of 30,000 ft from the sea bed. 
• The dome of the volcano is 120 km long and 103 km wide covering almost 51% of the Hawaiian Island. The summit caldera of Mauna Loa is known as Moku‘āweoweo with an area of 15 square km and a depth of 180 metres. 
• It is an active shield volcano formed by the eruption of highly fluid lava. It has gentle slopes formed by the flow of the thin layer of lava which is low in viscosity. 
• It is one of the five volcanoes that form the Island of Hawaii but the largest one in mass and size. The lava from Mauna Loa is poor in silica, fluid, and non-explosive. 
• The shield-stage lava forming the slopes of the volcano is tholeiitic basalt which is made from a mix of magma and subducted oceanic crust. 

Eruptions from Mauna Loa 

• As per records, it is found that the shield active volcano has been erupting for over 700,000 years. The findings indicate that it emerged above sea level around 400,000 years ago.
• The magma that flows out of Mauna Loa is from the Hawaii hotspot that created the Hawaiian Island chain over millions of years.
• The most recent eruption from Mauna Loa was recorded from 24th March to 15th April in 1984. So far in history, it is recorded to have erupted 33 times from 1843, once every five years on an average.
• The first record historically witnessed volcanic eruption from Mauna Loa was in January 1983.
• The deadliest eruption from Mauna Loa so far was in 1868. It took place alongside the disastrous 1868 Hawaiian earthquake claiming the lives of 77 people.
• The eruptions in the years 1879, 1880, and 1881 led to the flow of lava to the boundaries of Hilo – the largest city on Hawaiian Island. It damaged some parts of the settlement but did not claim any lives.
• The last recorded eruption was in 1984 and the volcano has remained quiet for over 35 years, which is the longest in its history.

Mauna Loa and its Contact with Humans 

• As one of the largest subaerial volcanoes in both mass and volume, it has attracted the attention of many people. It was designated as a decade volcano, one of the 16 volcanoes identified by the International Association of Volcanology and Chemistry of Earth’s Interior. It was studied for its history of destructive eruptions and its proximity to human settlements.
• The five volcanoes that form the Island of Hawaii are considered sacred as per ancient Hawaiian religious practice. As per beliefs and mythology, it is believed that Mauna Loa is home to the volcano goddess Pele. 
• One of the trails called Ainapo Trail ascending from Kapāpala village ends at the summit of Mauna Loa at its caldera.
• The first attempt to summit Mauna Loa was made by James Cook during his third voyage but was unsuccessful due to the route.
• The first to summit Mauna Loa was botanist Archibald Menzies, Lieutenant Joseph Baker, George McKenzie of Discovery, and a servant named Jonathan Ewins, in the year 1794. 
• Currently, the Ainapo Trail is used for summiting that was reopened in the 1990s. There are two other routes often used by expedition teams to reach the top of Mauna Loa. 

Conclusion 

Mauna Loa is an active shield volcano that has gentle slopes that were built from the flowing lava from the eruption. It is the second-largest volcano on planet Earth after Tamu Mastiff but has the largest subaerial volcano in both mass and volume. It constitutes nearly 51% of the area on Hawaiian Island and rises almost 30,000 ft from the sea bed. In summary, the eruptions from the volcano are not very deadly as the lava is low in silicon and has low viscosity, leading to a gentle flow. So far, there were 33 recorded eruptions from the volcano out of which the one that took place in 1868 was the most disastrous. As per the latest data, Mauna Loa has been silent for 35 years with the last eruption recorded in 1984.