Volcano observations with ASTER and ASTER image database for volcanoes

Volcano observations with ASTER and ASTER image database for

volcanoes

Urai, Minoru

Geological Survey of Japan, AIST

Topics• Introduction• Overview of ASTER instruments• Volcano monitoring with ASTER

– Volcanic gas monitoring : Miyake-jima, Japan– Thermal anomaly monitoring : Sierra Negra,

Galapagos Islands

• ASTER image database for volcanoes• Conclusions

IntroductionResent volcanic hazard– Eyjafjallajokull 2010 : Over 100,000 flights cancelled

– Merapi 2006 : 17,000 people were evacuated

– Two people were killed by a pyroclasic flow

– Pinatubo 1991 : Up to 800 people were killed

– In 1992 and 1993, the average temperature in the Northern Hemisphere was reduced 0.5 to 0.6°C

Historic volcanic hazard– Tambora 1815 : 92,000 people were killed

– Unzen 1792 : 15,000 people were killed

IntroductionASTER can be used for volcano observations

(1)Topographic and geologic analysis,

(2)Mapping volcanic products,

(3)Eruption plume analysis,

(4)Discolored sea water and crater lake monitoring,

(5)Generating digital elevation models,

(6)Surface temperature mapping,

Overview of ASTERLaunch date 18DEC1999Platform Terra satelliteOrbit 16days polar orbitObservation time 10:30AMData recorder yes

Subsystems VNIR, SWIR,TIRStereo function yesTotal bands 14+1Swath width 60kmLifetime 6 years

Acquired scene Over 1,800,000 scenes

Overview of ASTER•ASTER has nadir (3N) and backward (3B) looking views.

•3N and 3B compose a stereoscopic pair.

•A DEM can be generated from the stereoscopic pair.

•However, DEM can not be generated cloud covered area and a DEM covers 60 km by 60 km.

ASTER stereo image function.(http://www.ersdac.or.jp/GDEM/E/2.html)

0

0.2

0.4

0.6

0.8

8 9 10 11 12

SO2 0g/m2

SO2 10g/m2

Wavelength

Miyake-jima is located about 180km south of TokyoSO2-rich plume absorb thermal emission from sea at 8.6µm Cyan color indicates that temperature derived from band 11 is lower than others

ASTER TIR RGB : 11, 13, 14On November 8, 2000

Volcanic gas monitoring : Miyake-jima, Japan

Volcanic gas monitoring : Miyake-jima, Japan

No Height

(m)

Wind velocity

(m/s)

Wind direction (degree*)

1 286 9.0 305

2 765 11.7 296 3 794 12.5 298

Plume heights, wind velocities and directions estimated from ASTER

Nadir viewing image

Backward viewing image

Volcanic gas monitoring : Miyake-jima, Japan

ASTER TIR

MODTRAN

2D- SO2 distribution

MODTRAN

Plume height

SO2 flux estimation

ASTER stereo pair

Wind velocity

Atmospheric profile

Plume height and wind velocity analysis

Sea surface temperature

SO2 flux

B13 B11

Volcanic gas monitoring : Miyake-jima, Japan

The estimation of two-dimensional SO2 distribution

Volcanic gas monitoring : Miyake-jima, Japan

Measurement

line

Measurement

time

Wind speed

[m-s]

SO2 flux

[t day-1]

L1 – L1’ 11:44 – 11:53 8 3.22 x104

L2 – L2’ 11:55 – 12:07 8 3.09 x104

L3 – L3’ 12:18 – 12:29 8 2.67 x104

SO2 flux measured by COSPEC

Distance from the vent (km)

SO2

flux

(to

n/da

y)

The estimation of SO2 flux

thC

h CdsQ sin

α = 7 1 ° V h = 1 1 .1 m /s

0

1 104

2 104

3 104

4 104

5 104

6 104

7 104

0 5 10 15 20 25

Caldera collapse and lava flow : Piton de la Fournaise

• Piton de la Fournaise is one of the most active volcanoes located on the French island of Reunion in the western Indian Ocean.

• There are three calderas that were formed by progressive eastward slumping of the volcano.

Caldera collapse and lava flow : Piton de la Fournaise

On April 2, 2007, a new 1 km long vent opened at 650 m altitude in the southern part of Grand Brule. The lava flows reached the sea.

On April 5 to 6 and over the whole following day, the summit (Dolomieu) crater floor collapsed.

ASTER VNIR image taken on June 8, 2005

Caldera collapse and lava flow : Piton de la Fournaise

October 31, 2006

April 17, 2007

Caldera collapse and lava flow : Piton de la Fournaise

May 6, 2007 (after eruption) June 8, 2005 (before eruption)

VNIR images with 100 m contour

Caldera collapse and lava flow : Piton de la Fournaise

ASTER DEM differenceE-W ASTER DEM profile

Depression : 320 m at mostTotal volume : 9.6 107 m3

Caldera collapse and lava flow : Piton de la Fournaise

New lava deposit area : 3.85 km2

Surface temperature distribution derived from ASTER nighttime observed on May 4, 2007 superimposed on

ASTER daytime image observed on June 8, 2005

ASTER image database for volcanoes

△ Rank A (104)△ Rank B (220)△ Rank C (640)Volcanoes monitored by ASTER

Global volcano monitoring plan with ASTER

ASTER image database for volcanoes

Google Earth Version of ASTER image database for volcanoes athttp://igg01.gsj.jp/vsidb/image/vsidb.kml

ASTER image database for volcanoes

Full resolution display of ASTER image database for volcanoes

ConclusionsThe ASTER’s ability to monitor volcanic activities, such as thermal anomalies, topographic changes, volcanic gases, among others, has been validated.

A web-based ASTER Image Database Volcanoes is opened to the public (http://igg01.gsj.jp/vsidb/image/index-E.html). The database contains all ASTER images of 964 active volcanoes.