Before and after images from radar data provided by a Japan Aerospace Exploration Agency satellite reveals just how much of Anak Krakatau disappeared following its eruption.

(Geospatial Information Authority of Japan via AP)

At a Glance

Before and after radar images of Anak Krakatau reveal how much of the volcano disappeared following its eruption.Radar imagery shows that the volcano's entire southwestern flank has vanished.The volcano lost around 750 feet in height in the collapse.

Before and after radar images of Anak Krakatau — the erupting volcano that triggered a colossal landslide that sent a devastating tsunami onto the beaches of Indonesia's Sunda Strait — reveal the volcano's southwestern flank has disappeared.

Radar data taken from a Japan Aerospace Exploration Agency satellite show just how much the volcano reduced in size .

“The challenge now is to interpret what might be happening on the volcano, and what might happen next,” said Sheffield University's Dave Petley, according to the Associated Press.

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Local officials asked people to keep their distance from the coastline along the Sunda Strait with the risk of another tsunami lingering.

A still comparison of Anak Krakatau before and after its eruption.

(Geospatial Information Authority of Japan via AP)

Post-eruption, , dropping from 1,110 feet tall to 360, Indonesia's Center for Volcanology and Geological Disaster Mitigation estimated. The volcano's volume was reduced from approximately 150 million cubic meters to 40 million cubic meters.

Compared to the Mount St. Helens collapse in 1980 which lost a volume of 2.5 cubic kilometers — or a million olympic swimming pools — , according to Concord University volcanologist Dr. Janine Krippner.

The waves you can see rippling near the volcano in the after picture are being caused by ongoing eruptions at the island, experts say.

Anak Krakatau is the descendant of Krakatau, known for its infamous eruption in 1883 that sent shockwaves around the world four times over and affected the global climate. Anak Krakatau began emerging from above sea level in 1929 and has grown in size ever since.