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Hawaii Is Getting Bigger Thanks to Lava Flow

Watch the "lava delta" phenomenon in action.

That red hot ocean water lapping against the rocks looks unreal, as if this National Geographic video is from Mars instead of Hawaii.

Photographer Warren Fintz, a bystander at the beach, caught footage of lava flow from the Kilauea volcano arriving at the Pacific shore of the Big Island, also known as Hawaii, early in the morning on July 26.

Turns out that lava will help make the Big Island even bigger. As the molten rock continues to collide with the waves—the first time this has happened since 2013—it will form new land mass along the coast. While the lava flow poses no real threat to the locals who live around there, visitors should be careful, the United States Geological Survey warns.

This isn't the first time lava flow into the ocean will have formed new land. This phenomenon is called a lava delta, which USGS describes as "when pahoehoe lava enters the ocean for extended periods of time [and] new land is created in the form of a fan-shaped platform." When lava flows into the ocean, it cools very quickly and shatters into fragments ranging in size from sand to block. "These fragments accumulate along the submarine slope to form a loose foundation that will eventually support overlying lava flows that build the delta above sea level," USGS reports.

Lava deltas grow laterally and toward the sea until they collapse, which is often caused by accumulating on steep submarine slopes. These collapses often cause submarine landslides, swallow people up people nearby, and trigger explosions. (And then, of course, there are supervolcanoes to consider.)

If it sounds scary that's because it is. USGS recommends that visitors avoid walking on lava deltas, especially by the edge. Instead, best to stay behind the former sea cliff, they advise. That's the best place to observe the spectacular displays caused by volcanic activity.