The satellite - also called Daichi - is scanning the two-mile-high mountain with its Advanced Visible and Near Infrared Radiometer type 2, and its Phased Array type L-band Synthetic Aperture Radar. JAXA said this is the first time two such satellite instruments have been used simultaneously, and the combination should be able to provide valuable data about the mountain's behavior with greater precision.

JAXA is providing the observational data to the International Charter on Space and Major Disasters, a multinational coalition of eight space and Earth-observation agencies that attempts to provide continuous and real-time data on potential natural disasters.

Indonesia's Directorate of Volcanology and Geological Hazard Mitigation has reported that Merapi's crater cracked on April 11, and volcanic fumes began rising by about 100 meters. The AVNIR-2 observation data clearly show the fumes as well as volcanic ash at the crater and its surrounding area.

The PALSAR data also clearly shows the undulating geographical character as radar reflection spreading radially from the crater to the foot of the mountain. The west side of the crater is dark, meaning weaker radar reflection, and that is considered to indicate different characteristics of the land surface.

Merapi was named by combining the Bahasa Indonesia words "merah," or "red," and "api," or "fire." It is one of the most active volcanoes in Indonesia, erupting massively in 1969 and about every two or three years since 1992. Every time lava has erupted from the crater, it has caused damage to the surrounding area, either from pyroclastic flows or landslides.

Related Links
Advanced Land Observing Satellite at JAXA
International Charter