Mauna Loa Volcano


The Mauna Loa Volcano is the largest volcano on the planet as it rises over 4 kilometers above the sea level but the 4 kilometers that you see on top is not even half the size of the volcano. From the seafloor it is an additional 5 kilometers and from the seafloor it is depressed an additional 8 kilometers which makes the sum a total of 17 kilometers or 56,000 feet from the base. Half of the island of Hawaii is made up by the volcano and its sheer size makes it about 85% of every other Hawaiian island combined.


The Mauna Loa Volcano is not only a big size; it is also one of the most active volcanoes in the world. Since the first documented eruption in 1843 there have been an additional 32 eruptions. The last eruption took place in 1984 but scientists believe that the current signs point to the fact that it will erupt again. The volcano is currently being monitored at all times for any unrest that it may show. Scientists also believe that the Mauna Loa Volcano has been erupting for 700,000 years at least with its emerging above the sea level taking place close to 400,000 years ago. The magma seen at the Mauna Loa Volcano comes directly from the Hawaii hotspot.

Comparing It To Kilauea

When you are in Hawaii you will be seeing several volcanoes and it is impossible to go without comparing them. The Mauna Loa Volcano is pretty close to the Kilauea Volcano and even though it is not as active as its neighbor, it is still considered one of the most active in the world. There are a total of 333,000 acres that form Hawaii’s Volcanoes National Park and Kilauea and Mauna Loa are the most famous of them. What you may not know is that it appears that both volcanoes are connected which would explain the behavior of both volcanoes. In fact, they used to think that Kilauea was a part of Mauna Loa until they discovered its own set of lava tunnels. The increased inflation of both volcanoes is due to the fact that there is increased pressure in the source of magma for the two of them.

Is The Mauna Loa Volcano Awakening?

For a while the Mauna Loa Volcano was undergoing deflating but recently that changed. From 2002 to 2005 the summit of the volcano started to reverse the deflating period which had taken ten years. In 2004 earthquake activity also increased but by 2005 it went down again. Scientists believe that Mauna Loa will more than likely erupt again within the next few years so it may be that the citizens of Hawaii will need to be on the alert regarding this awakening giant.


Because of its history the Mauna Loa Volcano has been designated as a decade volcano. There are only 16 such volcanoes in the world and it means that more attention needs to be paid to it. It is important to know that volcanoes in Hawaii do not usually produce multiple casualties. In fact the last one occurred in 1924 when an explosive eruption sent rocks to onlookers, killing one. One of the most common hazards that volcanoes in Hawaii like Mauna Loa can cause is inundation by lava. The lava flows are usually slow moving and do not usually exceed a walking pace but that is not necessarily the case. In 1950 the volcano erupted as much lava as Kilauea produces currently every three years. The lava reached the sea level in only four hours which destroyed large parts of the village known as Ho’okena Mauka as well as parts of the highway in the area. Other communities have also been affected by eruptions from the volcano.


The Hawaii Volcano Observatory or HVO is the organization that is currently monitoring Mauna Loa. A close eye is kept on the activity of the volcano due to its past history. Usually an eruption of the Mauna Loa Volcano will be followed by several tremors for a few days. Warning mechanisms and an observatory are used to cover the area. The more modern mechanisms for monitoring the volcano were installed in the early 1970s so an eruption in 1975 was forewarned by seismic unrest which lasted close to a year. The same happened for the last eruption in 1984 except that the tremors lasted three times as long.

Today the seismic network monitors Mauna Loa as well as several GPS stations, strainmeters and tiltmeters which are currently monitoring deformation in the ground which can be caused due to the swelling of the volcano’s magma chamber. With all the equipment used there are a lot more possible warnings when an eruption is close to happening. As if that were not enough there are also two gas detectors at the summit caldera and a webcam that keeps an eye on the volcano.


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Photo taken by: United States Geological Survey

Kilauea Volcano Facts


The Kilauea Volcano is the youngest volcano on Hawaii’s Big Island. Because when viewed from above it seems tiny in comparison to the neighboring volcano Mauna Loa, Kilauea was originally believed to simply be a satellite of Mauna Loa instead of a distinct volcano. Research that has taken place during the last decades, however, shows that not only is Kilauea a separate volcano, but its magna-plumbing system actually goes over 60 kilometers deep into the earth. The Kilauea Volcano sits on a curved line made up of other volcanoes such as Kohala and Mauna Kea.


The highest point on the Kilauea Volcano is slightly less than 4,200 feet. In addition, it has a large caldera at the summit that is 3 kilometers by 5 kilometers wide at the main depression but is 6 kilometers by 6 kilometers at the outermost faults and goes down 165 meters deep. The entire area of the volcano is 552 square meters. The oldest rocks found on the volcano date back 23,000 years and scientists estimate that the first eruption occurred between 300,000 and 600,000 years ago. Despite this, about 90% of the basaltic shield volcano found on the surface is made from lava flows that occurred less than 1000 years ago while 70% of the actual volcano’s surface is 600 years old or younger. The volcano gets its name, Kilauea, from the Hawaiian word meaning much spreading or spewing, referencing the frequent lava flows.

Nearby Wildlife

Because of the constant activity of the Kilauea Volcano, there are semi-frequent acid rains in the nearby Ka’u Desert, a barren region to the south of the volcano’s southwestern rift zone. Despite this, wildlife still manages to flourish in several nearby areas, especially those that are more or less undisturbed by the volcanic activity. In the Hawaii Volcanoes National Park, which contains most of Kilauea’s southern ecosystem, you will find a wide range of bird species in addition to several endangered species of sea turtles.

Eruption History

In addition to being the youngest volcano on Hawaii’s Big Island, the Kilauea Volcano is actually the most active of the state’s volcanoes in recent years; in fact it is one of the most active volcanoes on the entire planet. The volcano has been present in many Polynesian legends and it has been almost constantly active since the first recorded eruption which occurred around the year 1750. Most of the volcanic activity at Kilauea between 1750 and 1924 was smaller and originated in the lava lake found at the summit. In 1924, however, the volcano had an explosive eruption and from then to 1955 there was a period of short eruptions.

Current Eruption

Impressively enough, the current eruption of the Kilauea Volcano, named Pu’u O’o started 30 years ago! It began on January 3, 1983 at which point ground fissures opened and thin streams of molten lava appeared from a 7 kilometer long fissure. Throughout the course of the current eruption, the main exit point of the lava has shifted several times. It spent the first 3.5 years erupting from a central vent but in July of 1986, it suddenly moved down the rift 3 kilometers to the Kupaianaha shield, where it stayed until early 1992. When the eruption point changed, so did the style, shifting from high fountaining occurring in episodes to a continuous but quiet effusion in a lava pond.

In November of 1986, lava from this eruption point met the ocean at a point 12 kilometers away and covered Kapa’ahu along the way. The most destructive phase of the Kilauea Volcano’s current eruption began in 1990 when its lava flows flooded Kalapana, a nearby village where it destroyed more than 100 homes in just 9 months. The lava flow declined throughout 1991 but in 1992, eruptions began once again. Now lava flows usually come through the lava tubes and go into the ocean and there are few surface flows.

Throughout the current eruption, lava flows have varied greatly, ranging from 300,000 to 600,000 cubic meters each day and there were actually 24 days during early 1997 in which there was no eruptive activity.

Research And Preservation

At the rim of the Kilauea Volcano you will find the Hawaiian Volcano Observatory, which was founded in 1912 by Thomas Jagger and this is where most of the research on the volcano takes place. In addition, the Hawaii Volcanoes National Park was created in 1916 by Woodrow Wilson. This began the area’s path towards becoming a World Heritage Site.


The first hotels appeared around the rim of the Kilauea Volcano in the 1840s. After the area became a National Park in 1916, tourism continued to increase greatly. Today around 2.6 million tourists visit the volcano and surrounding areas each year, mostly due to its location in beautiful Hawaii combined with its active yet docile nature.


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