Last Updated : December 12, 2019

The 2019 White Island Volcano Eruption, New Zealand

White Island Volcano observed by Synthetic Aperture Radar (SAR)


A large eruption occurred at White Island volcano in New Zealand on December 9, 2019 (UTC). We analyzed Synthetic Aperture Radar (SAR) data of ALOS-2/PALSAR-2 to investigate the ground surface changes associated with the eruption.
  • We can recognize the ground surface changes within the caldera area in the intensity images before and after the eruption. No substantial change can be seen outside the caldera area (figs.1 and 2).
  • No significant ground displacement were observed before and after the eruption (fig.3).
  • Slight ground displacement can be seen in the summit area before the eruption, which is consistent with the fact that ground subsidence with 1-2 cm has been observed from March to November, 2019 by GNSS observation* (fig.4).
* Resutlts of GNSS observation at the summit area by GNS science

SAR intensity image

SAR intensity image before the eruption SAR intensity image after the eruption
Fig.1 Comparison of SAR intensity image (left: before the eruption, right: after the eruption). [PNG:347KB, PNG:351KB]
(The topography may look distorted in the SAR image.)

Animation of SAR intensity image
Fig.2 Animation of SAR intensity image. [Animation GIF:1.4MB]
(The topography may look distorted in the SAR image.)

SAR Interferograms

Fig. 3 SAR Interferogram before and after the eruption.[PNG:181KB]

SAR Interferograms
Fig.4 SAR Interferograms before the eruption.[PNG:190KB]

Analysis Conditions

Fig.5 Area of interest
Fig. # Date Time
Mode *
1,2,3 2019-11-13
12:54 Asc. Right F 36°
4 2019-03-06
12:54 Asc. Right F 36°
* F:Fine(10 m)

Analysis by GSI from ALOS-2 data of JAXA.
These results were obtained through the activity of the SAR analysis working group of Coordinating Committee for Prediction of Volcanic Eruption


ALOS-2 (Advanced Land Observing Satellite 2) launched by Japan Aerospace Exploration Agency on May 24, 2014

Copyrights and Credits

Copyright (C) Geospatial Information Authority of Japan, All rights Reserved.

We welcome links from your website to this website. When using materials on this website, we ask that proper credit be given.


YARAI Hiroshi: Head of Division
KOBAYASHI Tomokazu: Chief Researcher
contact us