On the high peaks of Hawaii’s Mauna Loa (south) and Mauna Kea (north) a cap of brilliant white snow covered the summits on January 14, 2005, when this image was captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite. The third volcano that makes up the island is Kilauea, where ever-present lava flows give off a heat signature detectable by MODIS (area outlined in red). Charcoal streaks of cooled and hardened lava reach down the brown flanks of the volcanoes toward the ring of lush forests that climb the lower slopes. A speckling of gray around the notch in the middle of the northeastern coastline is the island’s largest city, Hilo.
Of the three volcanoes, Mt. Kilauea is the most active, having started its most recent erupting in 1983, and not stopping since. The vast majority of the surface of the volcano is covered by lava flows less than 1,000 years old, which reveals how active and prolific the volcano has been.