Kīlauea

Kīlauea is a highly active shield volcano located on the southeastern shore of Hawaii Island.

It is one of the most active volcanoes on Earth. The volcano is estimated to be between 210,000 and 280,000 years old. It first rose above sea level about 100,000 years ago. Kīlauea is the second-youngest volcano produced by the Hawaiian hotspot. This hotspot is a location in the Earth's mantle. The volcano is part of the Hawaiian–Emperor seamount chain. This chain of volcanoes and underwater mountains stretches 6,000 kilometers. It reaches from Hawaii all the way to the Kuril–Kamchatka Trench in Russia.

Geologically, Kīlauea formed as the Pacific tectonic plate moved over the Hawaiian hotspot. This process has continued for 70 million years. Kīlauea began as a submarine volcano. It grew larger through underwater eruptions of alkali basalt lava. Eventually, it emerged from the sea through explosive eruptions. Today, the volcano has a shield shape. This shape comes from the way lava flows out of it. Most of the volcano's bulk is still underwater. The part above the water has a surface area of about 385 square kilometers. This area makes up 13.7 percent of the total surface of Hawaii Island.

The structure of Kīlauea includes a large summit caldera named Kaluapele. A caldera is a large pit at the top of a volcano. Kaluapele has walls that reach up to 600 meters high. Within this caldera lies Halemaʻumaʻu. This is a large pit crater that has been a very active eruption center. Between 2008 and 2018, Halemaʻumaʻu held an active lava lake. Kīlauea also features two distinct rift zones. These are long cracks where lava can escape. The eastern rift zone is very dominant and active. It features large pit craters and low-lying ridges. The southwestern rift zone is much smaller and less active. It has not seen a rifting episode since 1974.

The volcano's activity can be very intense. Kīlauea is known for both effusive and explosive eruptions. Effusive eruptions involve the steady outpouring of lava. Explosive eruptions can send ash into the air. In 1790, an explosive eruption killed more than 400 people. This was the deadliest volcanic eruption in what became the United States. In modern times, the 1983 to 2018 eruption was incredibly long. It lasted nearly 35 years and was one of the longest documented on Earth. During this time, the eruption produced massive amounts of lava. It resurfaced large areas of the land.

Significant damage occurred during the 2018 eruption. Activity shifted from the summit to the lower Puna district. Lava erupted from two dozen different vents. These vents created lava fountains that sent rivers of lava into the ocean. This event destroyed Hawaii's largest natural freshwater lake. It also destroyed the communities of Kapoho and Vacationland Hawaii. The County of Hawaii reported that 716 dwellings were destroyed. This eruption also caused the Halemaʻumaʻu lava lake to drain. This led to explosive collapse events at the summit. These events forced the closure of Hawaii Volcanoes National Park for months.

Scientists have studied Kīlauea for a long time. English missionary William Ellis provided the first modern account. In 1912, Thomas Jaggar founded the Hawaiian Volcano Observatory. This organization serves as the main scientific body for studying the volcano. In 1916, President Woodrow Wilson signed a law to create Hawaii Volcanoes National Park. Today, the park is a World Heritage Site. It attracts about 2.6 million visitors every year. Scientists use tools like GPS to monitor the volcano. They also study the lava to understand how the volcano works.

Kīlauea also interacts with its neighbor, Mauna Loa. For a long time, people thought Kīlauea was just a satellite of Mauna Loa. However, lava analysis shows they have separate magma chambers. Interestingly, their activity often seems to trade places. When Kīlauea is quiet, Mauna Loa is often active. In 2022, both volcanoes erupted at the same time. This was the first time this happened since 1984. Geologists believe magma pulses in one volcano might increase pressure in the other. This shows how the different parts of the island are connected through the Earth's crust.