The story of Hawaii is told by her volcanoes. The entire chain of Hawaiian islands has been formed by volcanoes, and a new island (the Lōʻihi Seamount, also known as simply “Loihi”) is already in the making!
The Hawaiian volcanoes are special because they are very far (3200 km or 2000 miles!) removed from the place you normally find them: tectonic plate boundaries. On Hawaii, they are formed because the pacific plate moves with the slow pace of 4 inches (10 cm) / year over a deep, stationary hotspot in the mantle, located beneath the present-day position of the Island of Hawaii (read more about the Hawaiian hotspot). A similar hotspot is responsible for the volcanism in Yellowstone.
Because the Hawaiian volcanoes “draw a line” as the pacific plate moves over the hotspot you can see by looking at a map of Hawaii which islands (volcanoes) were formed first, which island is the most recent addition to the chain (the Big Island), and even where new islands will form in the future!
This hotspot is also responsible for so much seismic activity that it makes Hawaii the #1 state most likely to feel an earthquake!
The Big Island’s 6 volcanoes
The Big Island is the youngest of the Hawaiian Islands. There are six volcanoes that have worked together over the last (give or take) one million years to create the Big Island. These volcanoes formed one after the other and partially overlap. From oldest to youngest their names are: Mahukona, Kohala, Mauna Kea, Hualalai, Mauna Loa and Kilauea.
These six volcanoes are responsible for a whole bunch of impressive world records such as: “most active”, “most massive (active)” and “tallest sea mountain”. Three volcanoes are still active: Hualalai, Mauna Loa and Kilauea. Kilauea is currently erupting while the other two could erupt at any time. Mauna Kea is dormant, Kohala inactive and Mahukona has probably never breached the ocean surface.
Each of these volcanoes has a story to tell, some of which you can find below. Oh, and before we forget, the Big Island is not the only Hawaiian island with active volcanoes. There is a new island in the making in front of the Big Island right now (Loihi) which will break the ocean surface in an estimated 10.000 / 100.000 years, and did you know that the Haleakala volcano on Maui could still erupt!?
1: Mahukona: Never an Island?
Mahukona is located off the northwest of the coast of the Big Island and is named after the nearby town of… Mahukona. It was the first volcano that started building the Big Island of Hawaii but is also the most recently discovered volcano of Hawaii. Its existence was first predicted by J.D. Dana in 1890 based on a ‘gap’ in the volcanic loa chain (Hawaii exists of at least two different chains, the “loa” and the “kea” chain. Find out more) but confirmation of his theorized volcano had to wait to 1987.
Mahukona is for Hawaiian standards a very small (±6000 cubic kilometers, more than 13 times smaller than Mauna Loa) volcano that stopped erupting about 350.000 years ago. The newest research indicates that Mahukona never actually breached the ocean surface, but stopped erupting while it was still ±900 feet below sea level.
You can find out more about Mahukona in Garcia et al. (2012) in the Bulletin of Volcanology.
2: Kohala – the oldest
Kohala is the oldest volcano on the island of Hawaii. It is about one million years old and erupted for the last time about 120.000 years ago. Kohala makes up the northern part of the Big Island (think: Waipi’o valley) and used to be a lot bigger. Shortly after its last eruption the northern part of the volcano collapsed into the ocean in a giant landslide. This landslide created the stunning sea cliffs of Pololu and Waipi’o valley, and also created a monster tsunami that reached a height of 500 m (1,640 ft)!
Here is some bonus science geek trivia: the Kohala volcano is so old that it experienced – and recorded – the last reversal of earth’s magnetic field 780.000 years ago!
3: Mauna Kea – Tallest sea mountain in the world
Mauna Kea is over 10,000 m / 33,000 ft tall from base to summit, which is significantly taller than Mt. Everest! Because the Big Island is so heavy, it makes a depression in the ocean floor (much like an iron ball on a rubber sheet). This causes the biggest part of the volcano to sink below the ocean, and leaves a ‘mere’ 4205 m / 13796 ft above the ocean. Still, Mauna Kea is the tallest sea mountain in the world.
Mauna Kea is a dormant volcano and was last active about 4,600 years ago. There are still sometimes (swarms of) earthquakes felt that originate from inside Mauna Kea, but these most likely are due to structural readjustment, and not to volcanic activity.
With its high altitude, dry environment, and stable airflow, Mauna Kea’s summit is one of the best sites in the world for astronomical observation. It houses one of the best observatories in the world, and if you happen to be on the Big Island, stargazing on Mauna Kea should be part of your plans!
4: Hualalai – got Kona Coffee?
The Hualalai volcano is probably best known for the black gold that comes from its slopes: Kona Coffee. The Hualalai is an active volcano but has not erupted for a while. The last eruption of lava dates back to 1801, and the last damaging seismic swarm of earthquakes (probably caused by a shallow intrusion of magma) happened in 1929.
The Hualalai volcano has historically been very active. Scientists estimate that 80% of its surface is newer than 5000 years. In the 100 years before 1801, there were no less than 6 different vents active on the Hualalai. The Kona International Airport was built on top of a large lava flow coming from one of these vents.
5: Mauna Loa – largest volcano on the planet!
Mauna Loa means “long mountain”, and not without reason. It is the largest active volcano on the planet if you look at volume or surface area! The summit rises more than 4 km above sea level (and 5 km below sea level), and the volcano is so heavy, that the sea floor is depressed by its mass another 8 km! Adding the number shows that the summit of Mauna Loa rises 17 km (56,000 ft) above its base!
Mauna Loa is also a very active volcano. It has erupted over 150 times in the last 1000 years, with the last eruption ending on April 15, 1984. Never in its recorded history has Mauna Loa been inactive as long as is the case now. When it erupts again, Hilo might be in danger.
Eruptions from Mauna Loa have more often endangered Hilo. One time this led to a spectacular (but futile) show of power by the air force. Because an eruption in 1935 was threatening Hilo, five bombers of the 23d and 72d Bombardment Squadrons of the United States Air Force dropped bombs in the path of the lava in order to divert it away from Hilo. This did little to divert the flow, but luckily the eruption stopped 6 days later and Hilo was saved.
More recently, during the last active phase of Mauna Loa, Hilo was under threat again. Flows from this eruption headed rapidly towards Hilo again but stopped about 2.5 miles (4.0 km) from the outskirts when the eruption ended after three weeks.
Right now evidence is building that the summit of Mauna Loa is filling with lava again. You can check the current status of the Mauna Loa at the USGS Mauna Loa update page or read this interesting USGS fact sheet called “Mauna Loa—History, Hazards, and Risk of Living With the World’s Largest Volcano”.
6: Kilauea – Erupting since 1983!
Kilauea is the youngest of 6 volcanoes on the Big Island and has been continuously erupting since 1983. Kilauea means “spewing” or “much spreading” in the Hawaiian language, and the Kilauea volcano certainly honors this name. Since 1952 there have been 36(!) separate eruptions, and 90% of the surface of the Kilauea volcano is less than 1000 years old!
This activity has a profound influence on current day Hawaii. Kilauea is one of the best (and most reliable) volcanoes in the world to see an active volcano, and the volcano attracts many visitors to the Island of Hawaii. For many of these tourists seeing the lava is the single most impressive event they say to have ever witnessed. During the current eruption over 500 acres of coastline have been added to the Island. This creation goes hand in hand with destruction, as many houses, historical sites, and beaches have disappeared under a thick sheet of lava.
Depending on the activity of the Kilauea, you see the active lava with your own eyes. You can hike up to the lava flow or see the glow above the Halema’uma’u crater at night. If there is no access to the lava by foot, you can always opt for a helicopter to fly you over red-hot filled craters.
The newest Hawaiian island: Loihi
Lōʻihi is the newest volcano on the Hawaiian chain and lies about 35 km / 22 mi of the southeast coast of the Big Island. The volcano is called “Lōʻihi” (the Hawaiian word for “long”) because of its elongated shape north and south of the summit. The last known eruption of Lōʻihi was in 1996.
With every eruption, Lōʻihi is slowly rising under the ocean surface. Right now the peak of Lōʻihi is about 1 km / 0.6 mi below the surface, and scientists estimate that it will take another 10.000 to 100.000 years before Lōʻihi becomes a ‘real’ island.
Volcano Cheat Sheet
If you have not had your fill of volcanoes you can read up on some worldwide volcano trivia. Please leave your own volcano facts and trivia in the comment section if you want to add something to this list!
- Most destructive (recent history): Mt. Tambora, Sumbawa, Indonesia. 10.000 deaths by the 1815 eruption, plus an estimated 110.000 by the following starvation and disease.
- Most active: Kilauea, Big Island, Hawaii. Active since 1983.
- Fastest growing: Mt. Paricutin, Mexico. Grew from 0 to 300 ft. in just 5 days (1942), and stopped erupting in 1953 when a height of 1,391 ft was reached.
- The Hawaiian words for lava “Pahoehoe” (meaning smooth, unbroken lava) and “A’a” (stony rough lava) are now used internationally to denote 2 (out of 3) basic kinds of lava flows. Read more about these two kinds of lava.