The Kilauea lava lake exploded on May 3, triggered by the collapse of a crater wall at the world's most-active volcano. The event resulted in a spout of fiery lava and smoke blasting from the bed of molten rock.
The Halema'uma'u Crater first formed in 2008, and has grown significantly larger over the last seven years. On Sunday, April 3, a wall at the geological feature broke apart, sending pieces of rock careening into the lake of molten lava.
"A portion of the Halema'uma'u Crater wall collapsed at 1:20 p.m. Sunday, May 3, 2015, impacting the lava lake and triggering a small explosion of spatter and a robust particle-laden plume. Fist-size clasts were deposited around the closed Halemaʻumaʻu visitor overlook," the United States Geological Survey (USGS) stated.
The lava lake near the summit of the volcano is the first such feature visible from a nearby visitor outlook center in four decades. The lake overflowed the Halema'uma'u Crater several times in the two days prior to the most recent explosion.
Volcanic eruptions pose significant risks to aircraft as well as residents. Ash released high into the atmosphere can enter jet engines, where heat turns the material into glass, clogging the mechanism. On the ground, sulfur dioxide (SO2) can cause health problems in people who breathe in the noxious gas.
"The ambient SO2 concentrations near the vent vary greatly, but are persistently higher than 10 ppm and frequently exceed 50 ppm (upper limit of detector) during moderate trade winds. The gas plume typically includes a small amount of ash-sized tephra.... The heaviest pieces are deposited onto nearby surfaces while the finer bits can be carried several kilometers before dropping out of the plume," the Hawaiian Volcano Observatory reports.
The explosion was recorded on webcams operated by the HVO, and the organization released a series of still images captured during the event. The explosion occurred just beneath the view of the camera, and molten pieces of lava can be seen flying through the air, driven by the powerful forces sweeping through the volcano.
The lava lake rises and sinks as gas builds and is released. However, the deposit of molten lava has continued to rise since April 2015, sitting just a few feet beneath the rim of the crater prior to the latest explosion. This is the 16th lava lake to form at Halema'uma'u Crater in the last 90 years. In May 1924, a series of explosions doubled the depth of the crater to 1,350 feet in diameter, and doubled its width.
Geologists continue to monitor the volcano for signs of further activity.