Monitoring the Lusi mud volcano, Java
 

Spot Image has been tasking the FORMOSAT-2 satellite since January 2007 to acquire imagery and track the Lusi mud volcano eruption. Two SPOT 5 images are being used as the baseline for comparison: one from 2005 before the eruption and the other from 7 August 2006. The volcano started erupting on 29 May 2006.

The volcano is near a railway and highway in farmland near small-scale industrial facilities. There are many villages in the area and a large, recent housing estate to the north of the crater. 
 
 

The crater can be identified with the smoke plume and mudflows all around.
The extent of the mud lake is 230 hectares (2.3 km²).
The average rate of expansion of the lake is 3.3 hectares a day since the start of the eruption.
The holding dams and basins built to contain the mudflow are most clearly visible to the north and south of the crater.
The road has been damaged but is not submerged. The railway is still untouched.

The crater is partially obscured by cloud.
The extent of the mud lake is 600 hectares (6 km²).
The average rate of expansion of the lake is 2.3 hectares a day since the start of the eruption.
The dams and retention basins have overflowed. New ones have been built further from the crater.

The road and railway, as well as buildings around the crater, are submerged.
The lake is expanding mainly northward (after the gas pipeline explosion) and southward.
Rainy season precipitation is running off the mud toward agricultural irrigation channels (orange arrows). 
 
 

Nearly 1 year after the eruption started (29 May 2006), the dams around the volcano have contained the mud flow since January 2007. But the dams are showing signs of cracking in the satellite image.
The extent of the mud lake has increased from 600 hectares (6 km²) to 604 hectares after a dam collapsed (arrow 1).
The average rate of expansion of the lake has slowed to 1.6 hectares a day since the start of the eruption.
 

The crater has widened to nearly 70 metres (arrow 1).
The extent of the mud lake is unchanged: 600 hectares (6 km2).
The average rate of expansion of the lake has slowed to 1.7 hectares a day since the start of the eruption.
More buildings have been submerged (arrow 2).

The dam around the crater has been breached on its south side to divert the mud flow (arrow 1).
A 1st channel formed by two parallel dams diverts the mud flow into a small retention basin (arrow 2).
A 2nd channel connects the mud lake to the Porong river (arrow 3).
The mud is changing the colour of the water in the Porong river (arrow 4).

Nearly 1 year after the eruption started (29 May 2006), the dams around the volcano have contained the mud flow since January 2007. But the dams are showing signs of cracking in the satellite image.

The extent of the mud lake has increased from 600 hectares (6 km²) to 604 hectares after a dam collapsed (arrow 1).

The average rate of expansion of the lake has slowed to 1.6 hectares a day since the start of the eruption.

Shoring up of dams (arrows 1).

Dam submerged by mud (arrow 2).

Dam collapsed and repaired (arrow 3).
 

1 year after the start of the eruption (29 May 2006), the mud flow has reached buildings now submerged inside the maximum extent zone (green line).

The extent of the mud lake is unchanged at 604 hectares.

The average rate of expansion of the lake has slowed to 1.55 hectares a day since the start of the eruption.

New dam (arrow 1).

Dam submerged by mud (arrow 2).

Mud is advancing toward buildings (dotted line + arrow 3).

Mud is advancing toward buildings (dotted line + arrow 1).

A large hangar has been submerged by the mud (arrow 2).

Runoff waters are being contained by dams at the foot of the volcano (arrow 3).

The mud has reached the north dams (arrow 1).

New dams and retention basins are being built (arrow 2).

Two large hangars have been submerged by mud (arrow 3).

The extent of the runoff waters has decreased (arrow 4).

The north basin is flooded and buildings are now completely submerged by mud and runoff waters (arrow 1).

A new dam and retention basin are being built to the west of the crater (arrow 2).

The south-west basin is being used to attempt to dry the mud (arrow 3).

New retention basin (arrow 4).

Water and mud are flowing over the dam (arrow 1).

One of the initial dams is now virtually submerged under the mud (arrow 2).

The west dams have been consolidated (arrow 3).

Experimental earthworks (arrow 4).

A new dam is being built to the east for a vast retention basin (arrow 5).

To the north of the mud volcano, run-off waters are now being diverted toward agricultural irrigation channels.

1 - Run-off waters are flowing over the North dam.
 
2 - A small retention basin to the north-west of the volcano is now submerged. 

3 - Run-off waters are spilling over into an agricultural irrigation channel (highlighted in blue). Another channel to the south of the volcano is diverting waters toward the Bali Sea via the Porong River. 

4 - The recently built retention basin north-east of the volcano backs onto another agricultural irrigation channel to control the discharge of run-off waters. 

5 - New earthworks.

1 - Run-off waters have submerged the corner of the south dam. Mounds of earth torn away from the dam are still visible. 
 
2 - Water in the south-east basin is being drained off by a canal into the Porong River. The river’s colour is no longer changed by the mudflow now that the south dam has been breached.

1 - Two large blue-grey basins north and south of the crater are holding back the mud. 
 
2 - Mud in the white basin to the west is being dried out to solidify this side of the volcano. Run-off waters are pooling in the southern part of the basin.
 
3 - A channel has been dug along the dam of the large southern basin to drain off mud directly into the Porong River. 
 
4 - Run-off waters are being held to the east of the volcano in two dark blue basins, one dammed off and the other still open on one side.

1 - A new dyke protects a railway bridge

2 - Channels have been dug in the southern basin. They drain off mud to an internal circular basin on the east side. With the channel dug along the western dam, a network is organized to control the draining of sludge into the river.
  
 

1 - The new dam started in June 2008 has been extended on the west side along the railway, and along a stream on the north side. 
 
2 - The channel is silting up where it discharges into the Porong River. A white fan-shaped deposit of mud has formed and is choking up the river. 
 
3 - The river changes colour after the old highway bridge. Mud is being pumped and drained away through a pipe on the roadway. 
 
4 - The pumping station has been set up on the old highway overlooking the inner retention basin where the runoff water channels converge.

The mud is drying up in some places around the volcano. Several factors explain this change: the summer monsoon or dry monsoon contributes to evaporation, the pumping and the drainage into the river is effective, the eruption is decreasing in intensity.

1 - Overflowing of sludge from the south basin to the two basins on the westside 
 
2 - Sheets of mud around the volcano appears in white, displaying a recent drying up.

1 - The opening in the dyke is marked by two white structures. 
 
2 - The centre of the south basin is drying up. The mud is flowing by two lateral canals.