January 2011 Monitoring of Volcanic Activity at Mt. Shinmoedake, a Part of the Mount Kirishima Cluster of Volcanoes

A small eruption was recorded on January 19, 2011 from Mt. Shinmoedake, part of the Mt. Kirishima volcano cluster. On January 26, the volcano erupted again. According to the Japan Meteorological Agency, white plumes were observed from the rim of the crater at about 18:50 on January 26, rising up to 2,000 m. The lava dome that had had a diameter of approximately 10 m on January 28 had expanded to 500 m two days later on January 30, and there were concerns for the occurrence of a pyroclastic flow. In view of the extent of intensification of volcanic activity, the eruption alert level was raised to Level 3 at 18:00 on January 26.

Satellite Images Acquired on March 1, 2011 (Synthetic Aperture Radar: SAR)

Imaging Specifications

Acquisition date and time : March 1, 2011, 18:10 (JST)
Angle of incidence : 31.14° (Ascending)
Acquisition mode : High Resolution SpotLight
Product : GEC
Polarized wave : HH

Eruption alert level 3 ongoing (entry to the mountains prohibited)

This is an image taken prior to the 13th explosive eruption (approximately one hour before).
A depression that is bigger than any that have been observed to date can be seen on the east side of the lava. It is believed to be a relative large crater.

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Satellite Image Acquired on February 23, 2011 (Synthetic Aperture Radar: SAR)

Imaging Specifications

Acquisition date and time : February 23, 2011, 06:10 (JST)
Angle of incidence : 52.15° (Descending)
Acquisition mode : SpotLight
Product : EEC
Polarized wave : HH

Eruption alert level 3 ongoing (entry to the mountains prohibited)

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Aerial Photographs Taken on February 19, 2011

  • East slope of Mt. Shinmoedake
    East slope of Mt. Shinmoedake
  • North slope extending from Mt. Takachihomine to Mt. Shinmoedake
    North slope extending from Mt. Takachihomine to Mt. Shinmoedake
  • South slope of Mt. Ohachi and Mt. Takachihomine
    South slope of Mt. Ohachi and Mt. Takachihomine

  • From the front, Mt. Nakadake, Mt. Shinmoedake, and Mt. Karakunidake
    From the front, Mt. Nakadake, Mt. Shinmoedake, and Mt. Karakunidake
  • South slope of Mt. Shinmoedake
    South slope of Mt. Shinmoedake
  • West slope of Mt. Shinmoedake
    West slope of Mt. Shinmoedake

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Satellite Image Acquired on February 18, 2011 (Synthetic Aperture Radar: SAR)

Imaging Specifications

Acquisition date and time : February 18, 2011, 18:10 (JST)
Angle of incidence : 31.14° (Ascending)
Acquisition mode : High Resolution SpotLight
Product : GEC
Polarized wave : HH

Eruption alert level 3 ongoing (entry to the mountains prohibited)

This is an image acquired prior to the 12th explosive eruption (approximately six minutes before).
A depression can be seen in the center part of the lava. The surface roughness of the area around the crater is believed to have become less obvious due to rainfall on the day before.

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Satellite Image Acquired on February 17, 2011 (Synthetic Aperture Radar: SAR)

Imaging Specifications

Acquisition date and time : February 17, 2011, 06:19 (JST)
Angle of incidence : 39.2° (Descending)
Acquisition mode : StripMap
Product : GEC
Polarized wave : HH

Eruption alert level 3 ongoing (entry to the mountains prohibited)

Deformation is observed on the slope.
This change is presumed to be the result of the thinning of a part of the slope surface that resulted in collapse of the slope.

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Satellite Image Acquired on February 12, 2011 (Synthetic Aperture Radar: SAR)

Imaging Specifications

Acquisition date and time : February 12, 2011, 06:10 (JST)
Angle of incidence : 52.15° (Descending)
Acquisition mode : SpotLight
Product : EEC
Polarized wave : HH

While volcanic activity is continuing intermittently, no significant changes are observed in the lava on the crater.
A crater-like formation is observed inside the lava.

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Aerial Photographs Taken on February 9, 2011

  • Mt. Shinmoedake, viewed from above Onaminoike
    Mt. Shinmoedake, viewed from above Onaminoike
  • Crater of Mt. Shinmoedake photographed from the north
    Crater of Mt. Shinmoedake photographed from the north
  • Mt. Shinmoedake photographed from the west
    Mt. Shinmoedake photographed from the west

  • Mt. Shinmoedake photographed from the south-southeast
    Mt. Shinmoedake photographed from the south-southeast
  • Mt. Shinmoedake photographed from the southeast slope
    Mt. Shinmoedake photographed from the southeast slope
  • Southeast slope of Mt. Takachihomine and the foot of the mountain around Mike-cho, Miyakonojo City
    Southeast slope of Mt. Takachihomine and the foot of the mountain around Mike-cho, Miyakonojo City

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Satellite Image Acquired on February 7, 2011 (Synthetic Aperture Radar: SAR)

Imaging Specifications

Acquisition date and time : 07 February 2011, 18:10 (JST)
Angle of incidence : 31.14° (Ascending)
Acquisition mode : High Resolution SpotLight
Product : GEC
Polarized wave : HH

In the data acquired this time, a shadow that appears to be a depression near the center part of the lava (area with little backscattering), as well as black points (cavities) that look like craters on the southeast side of the lava, were observed.
In addition, based on the situation around the Shinmoedake area, significant changes such as sedimentation and erosion were not observed on the black belt (range in which the ground surface has become smooth as a result of volcanic ash deposits) that is visible from the southeast to the east side of the crater of Shinmoedake, as well as on the upstream end of the gully.

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Satellite Images Acquired on February 6, 2011 (Synthetic Aperture Radar: SAR) Extraction of Differences in Comparison with Images Taken before Eruption

Imaging Specifications

Acquisition date and time : 06 February 2011, 06:19 (JST)
Angle of incidence : 39.2° (Descending)
Acquisition mode : StripMap
Product : EEC
Polarized wave : HH
Image
Image

Topographic changes in the third phase (before eruption, after eruption), around the crater of Mt. Shinmoedake

Image on the left: Before eruption, image acquired on December 13, 2010
This shows the situation before the crater became buried under lava. A black pool is observed on the bed of the crater.
Inside image: After eruption, image acquired on February 1, 2011
The crater has already become buried in lava, and an elliptical-shaped wrinkle is visible on the surface of the lava. A black belt extends from the crater in a southeast direction, and is believed to be the area in which ground surface has become smoother as a result of thick deposits such as volcanic ash. In addition, the northeast and southwest slopes appear bright; these are thought to be areas for which ground surface is covered in rough cinder, etc.
Image on the right: Image after eruption, taken on February 6, 2011
Compare to the image in the center, significant differences in the shape of the lava within the crater cannot be observed. However, slight changes can be seen in the shape on the southeast rim. In addition, assuming that the shape of the lava buried in the crater is cone-shaped (diameter of 500 m, depth of 60 m), we can predict that the volume would be more than three times that of the Tokyo Dome.

Image

Topographic changes in the second phase (before eruption, after eruption), around the crater of Mt. Shinmoedake

We crated a figure showing the changes in topography accompanying volcanic activity by overlapping the TerraSAR-X images acquired on December 13, 2010 (before the eruption) and on February 6, 2011 (after the eruption). Taking advantage of the characteristics of a TerraSAR-X image, this image extracts the areas of changes in ground surface unevenness. The parts shown in dark red or blue are believed to be areas that have changed as a result of volcanic activity.
The blue region shows a roughened surface and increased backscattering; this is presumed to be the region covered by cinder, etc., spreading from the southeast side of Mt. Shinmoedake to its center.
The red area shows a smoothened surface and decreased backscattering; this is presumed to be the region with a thick buildup of sedimentation such as volcanic ash, etc., spreading from within the crater of Mt. Nakadake and the southwest slope of the gully (a small valley), and from Mt. Ohachi to the area near the peak of Mt. Takachihomine.
Clear changes were not observed on the gully on the east of Mt. Shinmoedake.

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Satellite Images Acquired on February 1, 2011 (Synthetic Aperture Radar: SAR)

Imaging Specifications

Acquisition date and time : 01 February 2011, 06:10 (JST)
Angle of incidence : 52.11° (Descending)
Acquisition mode : SpotLight
Product : EEC
Polarized wave : HH
Image
Image

Black and white stripes spreading in concentric circles on the top of the lava dome are visible. However, these were created when the dome grew. According to some reports, changes were observed in the height of the dome. We can see that the dome continues to change day by day.
Approximately 1 hour 40 minutes after this image was acquired (at 7:54 a.m.), the fourth explosive eruption occurred.

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Satellite Images Acquired before and after the Eruptions (Synthetic Aperture Radar: SAR)

Image

Imaging Specifications

(Before eruptions)

Acquisition date and time : March 15, 2009, 06:19 (JST)
Angle of incidence : 39.22° (Descending)
Acquisition mode : StripMap
Product : EEC
Polarized wave : HH

(After eruptions)

Acquisition date and time : January 31, 2011, 06:27 (JST)
Angle of incidence : 21.36° (Descending)
Acquisition mode : StripMap
Product : EEC
Polarized wave : HH
Image
Image

Although there had been a crater lake inside the crater of Mt. Shinmoedake before the eruptions, the black region showing the water surface could not be seen in this image.
An area in the crater, with approximate diameter of 500 m and resembling a bowl facing downward, can be seen. This is believed to be a lava dome.

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History of Information Released

1st: 31.Jan.2011(JST)
2nd: 1.Feb.2011(JST)
3rd: 6.Feb.2011(JST)
4th: 8.Feb.2011(JST)
5th: 9.Feb.2011(JST)
6th: 14.Feb.2011(JST)
7th: 17.Feb.2011(JST)
8th: 18.Feb.2011(JST)
9th: 19.Feb.2011(JST)
10th: 3.Mar.2011(JST)

From the perspective of understanding the damage situation arising as a result of the disaster, and of providing information to the relevant organizations, PASCO waited for weather conditions that would prevent the occurrence of secondary disasters, and carried out aerial photographic surveys immediately in cooperation with KOKUSAI KOGYO CO., LTD. PASCO also carried out imaging using SAR satellite, regardless of atmospheric weather conditions.


We express our deepest sympathy to all who have been affected by the disaster.
We will strive even harder to be of service to all through the application of our spatial information processing and analysis technologies, as well as through our disaster prevention consulting expertise, in order to obtain accurate information on the disaster situation and assist in the recovery of the affected areas.


<TerraSAR-X : InfoterraGmbH, Distribution [PASCO]>
<Aerial photographs : PASCO, KOKUSAI KOGYO, Distribution[PASCO]>
*The reuse or copying of images and other information available here without prior permission is strictly prohibited.

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Please contact us for permission to distribute or copy the information (documents and images) recorded in this page.

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PASCO CORPORATION strived to make the information in this page as accurate as possible at the time of publication; however PASCO CORPORATION does not guarantee integrity or accuracy of the information recorded in this page. PASCO CORPORATION accepts no liability for any loss or damage directly or indirectly, arising from the use of this information or contents. In case the information provided in this page is evidently different from the actual, in order to correct it please contact us.

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