REPORT ON THE ACTIVITY OFFSHORE POINT RADIX
26th & 31st July 2007

The Point Radix event IS the result of mud volcano activity.

OBSERVATIONS

From our visit the following observations were made:

1.Turbulent white foamy water
2.Plume of discoloured water extending outwards some 300 meters in a ENE-WSW direction away from the area of activity.

3. Gas bubbles seen escaping on the water surface, also there was a strong hydrocarbon smell. In places there was a slight hydrocarbon sheen on the water surface.

DISCUSSION

The white foamy area is visible from a distance and on closer examination represents the point of origin, of a number of discoloured columns of water.
The general sea current approaches from an easterly direction and interacts in a number of ways as comes into contact with the feature. The major of the waves continue along this pathway without changing orientation. However, a few seem to change direction on interacting with the feature. The first impression is that the waves are breaking, as a result of them encountering a submerged feature. Our helicopter ride did not reveal with any degree of confidence the nature of the submerged feature.

It was suggested to the ODPM that further investigation was needed. It was suggested that a bathymetric or side scan sonar survey be conducted as well as water bottom sampling. The bathymetric or side scan sonar survey would be able to ascertain the true nature of the feature since it gives an idea of the water depths and if any changes had taken place. The water bottom sampling would indicate if mud was being extruded in the area.

On the 31st July 2007. we visited the area with the IMA and Coast Guard. Five attempts were made to sample the water bottom. The first sample was taken in the sediment plume and only coralline algae sediments were recovered. The second water bottom sample was taken approximately 150 feet away from the center of activity and again coralline algae sediments were recovered. At both points the water depth was 40 - 45 feet. A third sample was taken from the front of the activity with the same result as the previous two samples. The final sample did not reveal anything different from the others. However, a temperature probe that was lowered indicated the presence of mud on the sea bottom

A detailed bathymetric grid was done by the IMA, which revealed that the regional water depth was around 45 feet and the bottom topography was fairly flat. However, profiles across the center of activity conclusively show that water depth shallows very rapidly to about 5 feet below the water surface and then drops off rapidly. A north - south profile revealed that the base of the feature was 150 meters in diameter, while the shallowest part was 50 meters in diameter. The northern side of the feature was found to be steeper that the southern side, while the top was fairly flat. This topographical flat at the top was as the result of waves action, eroding the sediments at the top and resulting in the plume of discoloured water drifting downcurrent from the center of activity. Gas bubbles and the scent of hydrocarbons were noticed at or near the center of activity.

CONCLUSIONS

From our observations, it can be concluded that the feature is a mud volcano cone. The most compelling evidence was from the bathymetric survey that clearly showed a conical profile and the presence of mud on the sea floor.

Low resolution movie

Higher resolution movie

Comments or Questions?