NASA Images Show the Huge New Lake of Water in Hawaii's Kīlauea Volcano

NASA has released images that document the growth of a water lake inside a huge crater within Hawaii's Kīlauea volcano.

The lake started to form in the lowest part of the Halema'uma'u crater in July 2019 and has been rising steadily ever since, according to the space agency. This was the first time in recorded history that a water pond had appeared in Halema'uma'u.

Now the body of water—which is rusty brown in color due to chemical reactions measures up to 100 feet deep and has an area of roughly five football fields.

Kīlauea—which rises 4,190 feet above Hawaii's Big Island, making up around 14 percent of its total area—is one of the world's most active volcanoes. It has been erupting on a continuous basis since 1983.

Kīlauea has a large summit caldera—a massive depression or crater formed by the collapse of a volcano into itself after an eruption. Halema'uma'u is located within the larger caldera.

The NASA images show how the summit of the volcano has changed as a result of volcanic activity in recent years. Between 2010 and 2018, a large lake of lava emerged in the southeastern part of Halema'uma'u.

However, this drained away during a broader eruption beginning in May 2018 that eventually covered 13 square miles of land in lava over several months, destroying around 700 homes. During this eruption, part of the caldera floor also collapsed, leaving a hole nearly as deep as the One World Trade Center (1,700 feet tall) is high.

Halema‘uma‘u, Kīlauea volcano
After its lava lake drained and the floor dropped, water has been pooling up in the bottom of Halema‘uma‘u crater for several months. NASA

The set of images above, which were captured by the Landsat 8 satellite—operated by NASA and the United States Geological Survey—show the Halema'uma'u crater before the lava lake drained (left) after the partial collapse of the caldera floor (middle) and after water had collected in the crater (right).

Geologists say that the appearance of the pond is due to the levels of water below the ground in the area of the volcano.

Halema‘uma‘u crater, water lake
A close-up photograph of the water pond in the Halema‘uma‘u crater. NASA

"We have a drill hole a little more than one kilometer south of the crater where we measure the level of the water table," Don Swanson, a volcanologist at the U.S. Geological Survey's Hawaiian Volcano Observatory, said in a statement. "We know that the crater floor dropped a little more than 70 meters below the water table in 2018. Any time that you punch a hole below the level of the water table, water is eventually going to come in and fill that hole."