Kilauea is a shield volcano with broad, gently sloping sides built by fluid basaltic lava that flows across vast distances before cooling.

Kilauea is located on the southeastern part of the Island of Hawaii and ranks among the most active volcanoes on Earth. It is classified as a shield volcano because its broad, gently sloping profile resembles a warrior's shield lying on the ground. This distinctive shape results from low-viscosity basaltic lava that flows easily and spreads across vast areas rather than accumulating into a steep peak.Lava at Kilauea typically reaches temperatures of approximately 1,170 degrees Celsius (2,140 degrees Fahrenheit). This extreme heat keeps the silica-poor basaltic magma fluid, allowing it to travel several kilometers from the vent before solidifying. The United States Geological Survey (USGS) documents that Kilauea has maintained a state of near-constant eruption for decades, substantially reshaping the island's coastline.The Puʻu ʻŌʻō eruption, which began in January 1983 and lasted until 2018, was the longest-lived rift zone eruption recorded in the past 500 years. During this 35-year period, the volcano added more than 200 hectares of new land to the island as lava reached the Pacific Ocean. Scientists monitor Kilauea using a network of GPS stations and tiltmeters to track magma movement beneath the surface.Shield volcanoes like Kilauea differ fundamentally from stratovolcanoes such as Mount St. Helens, which have thick, viscous lava that leads to explosive eruptions. Kilauea's eruptions are characteristically effusive, meaning lava flows steadily from the ground rather than erupting explosively. This predictable behavior has made it a premier site for volcanological research since the Hawaiian Volcano Observatory was established in 1912.