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. Last Updated: 07/27/2016

Scientists Unlocking Kilauea's Secrets

KILAUEA, Hawaii -- The silver Hughes helicopter settled its skids on the glassy entrails of cold magma and idled its engine.

Four field geologists from the Hawaiian Volcano Observatory jumped out onto the field of black "pahoehoe" lava. They stumbled toward the monitoring site as quickly as they could drag their battered equipment cases across the sharp-edged spatter fissures.

Deep inside Kilauea, a kilometer beneath their feet, an immense plume of magma was on the move.

With portable tiltmeters, seismographs and satellite geodetic sensors, the scientists urgently sought the measure of that fiery serpent as it snaked its way toward the surface. By systematically recording the volcano's erratic pulse, their field instruments could provide an early warning of any impending disaster for tens of thousands of island residents.

For the U.S. Geological Survey volcanologists, it was just another morning atop the world's most active volcano.

In the previous 24 hours, the subterranean lava stream had shaken the mountain's foundations with a swarm of early-morning earthquakes.

Surprisingly, the violent movement choked off the longest recorded volcanic eruption in modern times.

Kilauea has erupted continuously since 1983, spewing enough molten rock to bury Manhattan to a depth of 36 meters. It has spurted fountains of fire more than 450 meters high and added 218 hectares of land to the island.

But as tremors shook Kilauea early Sept. 12, the streams of incandescent rock spewing from oceanside lava tubes abruptly dribbled to a halt. The cooling cliffs of new rock along a kilometer of the volcano's southern coast collapsed into the surf in explosions of steam.

The observatory team searched for answers. The laboratory has watched Kilauea and four other volcanoes on Hawaii since 1912. Like Kilauea, two of them, Mauna Loa and Hualalai, have erupted in the past 200 years.

Together, they form the southeastern end of a chain of volcanoes that began to evolve 70 million years ago, giving birth to an archipelago of islands and underwater seamounts. In the coming hours, the researchers hoped their instruments would reveal whether this unexpected lull in Kilauea was part of the ongoing eruption or a harbinger of a devastating change in the volcano's behavior.

The intrusion of so much new lava had created a series of underground fissures vast enough to dramatically lower the internal pressure of the eruption.

Almost immediately, the magma chambers began to re-inflate as new lava slowly filled the fissures. By Sept. 27, the scientists were able to detect a series of new lava tongues emerging sluggishly.

Kilauea, they concluded, is still awake and fuming.