Kīlauea is an active shield volcano that is located on the island of Hawaii and is located within Hawaii Volcanoes National Park. This volcano, which reaches an elevation of 4,091 feet, is one of five volcanoes that form the island and it is the most active. It is thought to be between 300,000 and 600,000 years old and is the second youngest of all the Hawaii volcanoes. It was formed when the Pacific tectonic plate moved over the Hawaiian hotspot and like other Hawaiian volcanoes, it began its development underwater. It is thought to have emerged from the ocean between 50,000 and 100,000 years ago.

The structure of Kīlauea has been subject to a nearly constant state of eruption, so the majority of its slopes consist of hardened lava flows, with some tephra and scattered ash that were produced from small eruptions. About ninety percent of the lava flows have been dated to historical eruptions from 1,100 years ago. Because this volcano is not topographically prominent and it appears to be attached to Mauna Loa, it was long thought to be an active satellite of its neighbor. Studies conducted on the lava flows of both volcanoes showed that they are fed from two distinct magma chambers. Kīlauea features a summit caldera that reaches four feet in depth, two rift zones that extend east and southwest from the caldera, the active Hilina fault system, and eruptive structures like lava tubes, cinder cones, and satellite shields.

The Hawaiian Islands are isolated from other landmasses, allowing it to develop a distinct ecological system that supports large numbers of unique species. However, this isolation also causes the islands to become easily threatened by outside influences like human development and invasive species. The first humans to populate Hawaii remained along the shoreline, but their development caused decreases in the populations of flightless birds and caused the forest along the shoreline to be converted into grassland. The island’s ecosystems are also affected by volcanic eruptions, which destroy areas of critical habitat. The human population on the island grew between the 12th and 18th centuries and growth eventually reached inward. Ancient Hawaiians considered the volcanoes to be sacred, associating them with deities. The first outsiders to visit Kīlauea kept records regarding its features and activity, but some of the most important records were those of James Dwight Dana and James Cook.

Although scientists have been able to date eruptions from this volcano as far back as 275,000 years, the first reliable historical record of an eruption dates back to 1820. The first well described eruption occurred in 1823, producing enough lava to begin filling the caldera, which was much deeper than today. Eruptions were limited to the caldera and continued to fill it until 1840, when the volcano entered a rare period of decreased activity, followed by a period of relative quiet until 1950. Most historical eruptions were effusive eruptions, while those before Europeans arrived are thought to have been mostly explosive.

Kīlauea’s next major eruption occurred between 1918 and 1919, resulting in a large lava shield known as Mauna Iki. Other major eruptions occurred in 1924 and 1952, both of which were followed by quieter periods or periods with no activity, and in 1960, after which the volcano has remained in a constant state of activity. Between 1969 and 1974, a major eruption known as the Mauna Ulu eruption covered much of the land in lava flows and added new land to island. However, the longest eruption of this and any other volcano began in 1983 and is still occurring today. By 2011, this eruption had covered forty-eight square miles of land, destroyed 213 structures, and added 509 acres of new land.

Today, Kīlauea is a popular tourist destination because it is the only constantly active volcano that is also safe enough to visit. About 2.6 million people visit the area every year, most of which take the route to the summit that also holds the Kilauea Visitor Center. The area also offers visitors places to rest as well as many hiking trails. This volcano is home to the Hawaiian Volcano Observatory, which was created in order to monitor volcanic activity.

Image Caption: Looking up the slope of Kilauea, a shield volcano on the island of Hawaii. Credit: USGS/Wikipedia