The Hawaiian Islands are truly unique in geographic terms. As the only state in the USA composed entirely of volcanic rock, Hawaii is riddled with incredibly impressive volcanoes that began evolving over 70 million years ago. Because of its volcanic origins, you could say that Hawaii is essentially just a chain of massive volcanoes that are rooted thousands of feet below the ocean floor. What you see above sea level is only a fraction of the giant volcanic topography that exists here. Each Hawaiian island is proof that the volcanoes that created it erupted many times to push the island above sea level. Although there are many volcanoes beneath the surface, below is an overview of the volcanoes that make up the Hawaiian island chain.
Volcanoes on the Big Island of Hawaii
Spanning a maximum width of 75 miles (120 km) and covering a land area of 2,035 square miles (5,271 km²), Mauna Loa makes up more than half of the surface area of the Big Island of Hawaii. Mauna Loa rises 13,679 feet (4,169 m) above sea level, making it one of the world's tallest mountains. Due to its elevation, Mauna Loa receives snowfall during the winter months. The name Mauna Loa means "Long Mountain" in the Hawaiian language. Another interesting fact is that Mauna Loa is the largest subaerial volcano in both volume and mass on Earth. Its volume is estimated at about 18,000 cubic miles (75,000 km³).
The first Mauna Loa eruption was recorded in 1843, and 33 subsequent eruptions have been recorded since. Mauna Loa's latest eruption occurred in March-April of 1984, and the volcano remains under constant observation by the Hawaiian Volcano Observatory as it is expected to erupt again in the near future. Eruptions at Mauna Loa tend to be non-explosive, and no recent eruption has caused fatalities. However, eruptions in 1926 and 1950 destroyed some villages.
Mauna Loa is a shield volcano, meaning it is a gently sloping mountain produced from a large number of generally very fluid lava flows. An interesting fact about shield volcanoes is that they can form on other planets. For example, the largest discovered mountain on a planet in the solar system is Olympus Mons, located on Mars.
Kohala is around one million years old (breached sea level more than 500,000 years ago), which makes it the oldest of all subareal (on dry land) volcanoes. Kohala is a shield volcano that rises at 5,480 feet (1,670 m) above the sea level. It encompasses 234 square miles (606 km²) and thus comprises 5.8% of the land area of the Big Island of Hawaii. Its volume is about 3.400 cubic miles (14,000 km³). It is estimated that Kohala's erupting activity began to diminish 300,000 years ago when the volcano was twice as wide as it is now, and it is currently an inactive volcano. The last eruption occurred about 120,000 years ago.
While Kohala was gradually diminishing in activity, the younger volcanoes Mauna Kea and Mauna Loa buried its southern flanks. This factor makes it difficult to determine the volcano's exact shape and size during its element phase.
As the youngest volcano of the Hawaiian volcanic chain (around 400,000 years old), the Lo'ihi Seamount remains 3,000 feet (975 m) beneath the ocean's surface as a subaqueous type. This undersea mountain 22 miles (35 km) off the southeastern coast of the Big Island rises 10,000 feet (3,000 m) above the ocean floor. Lo'ihi is expected to begin emerging above sea level about 10,000 to 100,000 years from now. The name Lo'ihi means "long" and was given due to the volcano's elongated shape.
Its current location on the "Hawaiian hotspot" is also shared with active volcanoes Mauna Loa and Kilauea. Once dormant, Lo'ihi again became an active volcano with a sizeable eruption in 1996. Since 1996, Lo'ihi has been only intermittently active.
As one of the most active volcanoes on earth, Kilauea is also the youngest. Located in the southeast region of the Big Island, Kilauea sits on the flank of the active Mauna Loa volcano. Kilauea is a highly studied and constantly monitored because of its continuous lava flow from the cinder and spatter cone of Puu Oo along the east rift zone.
The name “Kilauea" means "spewing" or "much spreading," referring to the constant eruption that began in 1983. Kilauea volcano is an integral location in Hawaiian mythology – It is considered by many to be the home of Pele, the goddess of fire and volcanoes. Pele can be kind and gracious if appeased, or show anger if disresected in the form of fiery volcano activity.
The shield volcano Mauna Kea rises 13,784 feet above sea level, and continues another 15,000 feet below sea level. That’s a total height of about 29,000 feet, making it the tallest volcano and mountain on earth! “Mauna Kea” means “White Mountain” in Hawaiian and this particular volcano is a bit different than its neighbors Mauna Loa and Kilauea. Mauna Kea is currently dormant, its last eruption occurring about 4,500 years ago. It has fewer eruptions, steeper topography, no summit caldera, and varying chemical compositions in its lava. Mauna Kea is also unique because the volcano is home to glacial deposits formed thousands of years ago. Not many people realize that glaciers exist in Hawaii! Because of its height, the summit of Mauna Kea also receives snowfall in the winter.
Mahukona volcano is a subaqueous volcano located on the northwest side of the Big Island. Once an above ground volcano that topped 800 feet, Mahukona now resides 3,600 feet below sea level. The name “Mahukona” means “Leeward steam” in Hawaiian.
Hualalai has the distinction of being the third youngest and third most historically active volcano on the Big Island (after Mauna Loa and Kilauea). The town of Kailua-Kona, birthplace of the infamous Kona Coffee, is built on the southwestern slope of Hualalai. Hualalai is named after the wife of Hawaii Loa, a famous Hawaiian navigator.
Hualalai is credited with creating numerous lava flows in the past. The Keahole Airport is built atop one of Hualalai’s lava flows. A series of earthquakes in 1929 are evidence that Hualalai may threaten Hawaii with an eruption again within this century.
Volcanoes on Maui
The two volcanoes that make up the island of Maui are East and West Maui.
East Maui Volcano
It is also known as Haleakala is the only other Hawaiian volcano besides Kilauea to have erupted since the late 1700s. As the third largest volcano in the Islands, Haleakala has a very active history, with ten eruptions estimated in the past 10,000 years, the last eruption dated 1790. In geologic time frames, this is considered very active! Thus, many scientists believe Haleakala may be due for another eruption again soon.
The Hawaiian term “Haleakala” literally means “House of the Sun”, and the summit of Haleakala holds a prominent place in Hawaiian history and mythology. Haleakala Crater at the summit of the volcano is an ever popular tourist destination.
West Maui Volcano
It is said to have been formed between 1.3 and 2 million years ago. Scientists estimate the last eruptions occurred about 1 million years ago; however, West Maui is considered extinct and non-threatening today.
Volcanoes on Molokai
The two volcanoes that comprise the island of Molokai are West Molokai, sometimes referred to as Mauna Loa, and East Molokai, otherwise referred to as Wailau.
West Molokai volcano is the smaller of the two (above sea level), and East Molokai encompasses the eastern two-thirds of the island. Much of West Molokai lies below sea level, is buried by lava flow from other volcanoes, or was moved through the landslide process.
Volcanoes on Oahu
The Koolau and Waianae volcanoes comprise the island of Oahu. Waianae towers over the western or windward half, and Koolau rises over the eastern or leeward side.
It is a basaltic volcano, comprises roughly two thirds of the island of Oahu.
The infamous Diamond Head Crater, Hanauma Bay and Koko Crater are volcanic features that draw thousands of tourists a year. Koolau is a favorite volcanic subject as its lavas are unique in makeup with higher silica content than other Hawaiian volcanoes.
Waianae volcano is the taller and older of the two. It is also much drier than Koolau, keeping the coastal waters pristine due to lack of runoff.
As Hawaii’s volcanoes continue to erupt, the Hawaiian Islands continue to grow and change. Out of the destructive eruptions comes the land that perpetuates life in Hawaii. Take a visit to one of these amazing volcanoes and see for yourself how these beautiful islands were (and continue to be) created.