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Observation Result for Eruption of Anak Krakatau Volcano in Indonesia by ALOS-2

Overview

Posted: Dec. 26, 2018, 9:00 (UTC)

  • On December 22, 2018, Tsunami probably related to the eruption of Anak Krakatau caused serious damages on coastal cities close to the island.
  • JAXA performed an emergency observation by ALOS-2 (“DAICHI-2”) on December 24, 2018 (UTC), and ALOS-2 captured significant topographic changes in the southern island.

On December 22, 2018, Anak Krakatau erupted and the probably-related tsunami caused serious damages on coastal cities. JAXA performed an emergency observation with the Phased Array type L-band Synthetic Aperture Radar-2 (PALSAR-2) aboard the Advanced Land Observing Satellite-2 (ALOS-2, "DAICHI-2") on December 24, 2018. Table 1 summarizes the observation data by ALOS-2. Figure 1 shows the observation area by ALOS-2.

Fig. 1: Observation area by ALOS-2.
Fig. 1: Observation area by ALOS-2.
Table 1: Overview of observation by ALOS-2
Observation date Path Mode Orbit Direction Beam Pol.
December 24, 2018135Stripmap 10mAscendingRightF2_5HH+HV
Figure 2 shows a comparison of intensity images on August 20 and December 24, 2018. Significant topographic change in the southern part of the Anak Krakatau Island was recognized in the white-dotted circle in the figure.
Fig. 2
Fig. 2: Comparison of the two HH amplitude images acquired before (August 20, 2018) and after (December 24, 2018) the eruption. The white-dotted circle shows Anak Krakatau Island.
(Click to view enlarged image)
Figure 3 shows a polarimetric color-composite image (red: August 20 HV polarization, green: December 24 HV pol., blue: December 24 HH pol.), where the topographic change is easier to identify than Figure 2.
Fig. 3
Fig. 3: Polarimetric color-composite image acquired before (August 20, 2018) and after (December 24, 2018) the eruption.
(Click to view enlarged image)
JAXA EORC