Hawaii volcanoes are known as shield volcanoes due to the characteristic shape they take on as the lava flows outward. Each has its own distinct features. While the entire chain of Hawaiian volcanoes extends more than 3000 miles (nearly 5000 km) across the Pacific Ocean, most have been quiet for hundreds of thousands, even millions of years.
The Big Island was formed by 6 volcanoes: Mahukona, Kohala, Mauna Kea, Mauna Loa, Hualalai and Kilauea. The Mahukona Volcano is now submerged off the northwest shore, having sunk beneath the sea and become extinct more than 400,000 years ago.
While Kilauea is the active volcano Hawaii is most famous for, there are actually three “active” volcanoes on the Big Island. The other two active Hawaii volcanoes are Mauna Loa and Hualalai. All this really means is that there has been an eruption one or more times in the last 10,000 years, and there is sufficient seismic activity below the surface to suggest that another eruption could occur in the next, say, 1000 years or so.
Mauna Loa has erupted at least 35 times since 1843, most recently in 1984. At 10,000 cubic miles of rock, it is the most massive mountain in the world. With a width of 75 miles (120 kilometers), Mauna Loa makes up approximately half of Hawaii Island. It is more than 100 times the size of Mt. St. Helens in Washington. It is so massive that it is actually sinking deeper beneath the ocean under its own weight. It rises 13,677 feet (4169 meters) above sea level, descends 16,400 feet (5000 meters) to the ocean floor, then depresses the ocean floor another 26,000 feet (8,000 meters), for a total height of more than eight miles below the ocean's surface!
Hualalai is the third most active volcano on the Big Island. Many homes and resorts have been built on the flanks of this volcano above Kailua-Kona. In 1929, intense earthquake activity beneath the surface, lasting for several weeks, was likely caused by rising magma. Because of this and the fact that it has been over 200 years since its last eruption, Hualalai is considered a potentially dangerous Hawaiian volcano that is overdue for an eruption. Hualalai last erupted in 1801.
Mauna Kea Volcano is considered dormant (a sleeping giant), having last erupted about 3,500 years ago. When measured from its base, Mauna Kea is the tallest mountain in the world. The Mauna Kea Observatory, the world's largest astronomical research facility, is located at the summit.
Just northwest of Mauna Kea, diminutive (relatively) Kohala is considered extinct, having last erupted 60,000 years ago. Many of the premier Big Island Resorts are built along what is often referred to as the Kohala Coast, although the true coast of the Kohala volcano is farther to the north.
Of all the Hawaii volcanoes, only Kilauea Volcano on the Big Island is currently erupting, as it has been doing continuously since January 1983. Hawaii Volcanoes National Park showcases this fascinating volcano, located about 50 minutes from Hilo or a 2-hour drive from Kailua-Kona.
Fun for the entire family, Hawaii Volcanoes National Park is a great place to explore and learn more about all the volcanoes of Hawaii. You can see steam vents and the stunning Kilauea caldera (summit crater), visit the Jaggar Museum on volcanology, and walk through the amazing Thurston Lava Tube. Tons of great hiking too, from easy to strenuous.
To get the most out of the experience, consider going with a knowledgeable and friendly guide! We have a variety of Big Island volcano tours to choose from.
Can you walk out to see lava flow? Can you watch lava flow into the ocean? Great questions. Your opportunity to view Kilauea's lava flow is inconsistent at best. For years you could almost always count on being able to watch molten lava ooze straight into the ocean. Then it all stopped abruptly in March 2011 when the floor of the Pu‘u ‘O‘o crater collapsed and redirected the flow. Since that time lava flow has been unpredictable. This Big Island volcano can be very tempermental!
The most accurate and up-to-date information on current lava flow from Kilauea can be found on either the National Park Service website for Volcanoes National Park or the Hawaiian Volcanoes Observatory website. If you are hoping to see actual lava flow during your Hawaii vacation, be sure to check one of these websites.
Of course, things can change at a moment's notice with an active volcano in Hawaii, depending on the whims of the Hawaiian volcano goddess Pele!
The story of Hawaii volcanoes and the creation of the extensive island chain is a fascinating one. Hawaii is geologically unique, formed by a "hot spot" in the middle of the Pacific Plate.
All of Earth’s tectonic plates are relatively thin, thinner under oceans. Beneath them is the magma of Earth’s interior. Over time these tectonic plates move slowly on the hotter, more fluid mantle underneath.
Far beneath the floor of the Pacific Ocean, pools of fiery magma (molten rock) have broken through a thin spot in the Pacific Plate, creating undersea volcanoes. As large amounts of cooled lava rock pile up while more magma oozes up from below, some of the volcanoes eventually rise high enough to break the ocean surface, forming an island.
Over the last 75-80 million years, the Pacific Plate has moved over the hot spot, creating not only the islands of Hawaii but the entire 3,105 mile (4,997 km) chain of volcanoes known as the Hawaiian-Emperor Chain. Over millions of years as the Pacific Plate moves over the hot spot, the original volcano begins to erode and become inactive, with a new volcano forming in the same area.
Kaua'i is the oldest of the main Hawaiian Islands at about 5 million years. It is also the farthest north (makes sense, right?). The Big Island of Hawaii is the youngest, with surface lava flows less than 1 million years old.
The Hawaiian hot spot is roughly 50 miles (80 km) in diameter. Today, one edge of it is below the Big Island, fueling the active eruption of the Kilauea volcano, while another edge is beneath the erupting Lo'ihi Seamount, south of the Big Island and 3,000 feet (914 meters) beneath the ocean's surface. Some scientists estimate that Lo'ihi will rise above the ocean's surface in as little as 10,000 years, while others suggest it will more likely be more than 50,000 years, if at all. The Pacific Plate continues to move northwest at a rate of about 3.5 inches/9cm per year.
There are two distinct types of lava which are known universally by their Hawaiian names, a’a and pahoehoe (pronounced paa-hoy-hoy). While quite different in appearance, their chemical composition is essentially the same.
A’a lava tends to flow through channels on the surface, whereas pahoehoe often travels through underground tubes. A’a has more crystals and fewer gas bubbles than pahoehoe, the gas bubbles being squeezed out as the lava thickens while cooling. Once cooled, a’a is rough, clumpy and often sharp, making it difficult to walk on. Should you fall on it, you will quickly understand why it is called a’a!
Pahoehoe lava has a smooth, ropy appearance, similar to thick chocolate cake batter. A higher concentration of gas bubbles contributes to the puffy appearance characteristic of pahoehoe lava. Lava tubes are formed when the outer crust of a pahoehoe flow hardens while the river of lava continues to flow inside the tube.
Often the same eruption can produce both pahoehoe and a’a lava. It is also possible for lava that starts out as pahoehoe to change to a’a as it loses gas and cools while moving farther from the erupting vent. In general eruptions with a great deal of lava more commonly produce a’a, whereas lesser flows are generally pahoehoe.