Acid rain damaging vegetation in some areas – Geologist

While the hazards of the second growing dome at La Soufriere are still confined to the crater, damage to vegetation at the summit has already been observed as one of the effects of the ongoing effusive eruption.

Geologist, Professor Richard Robertson updated the nation on the activity at St Vincent and the Grenadines’ volcano on Sunday during a call to WeFM’s radio programme, ‘Issues at Hand’.

Professor Richard
Robertson

The geologist, who is part of a team from the University of the West Indies Seismic Research Centre (UWI-SRC) that arrived to monitor the ongoing eruption, said the rate of growth of the second dome has slowed slightly.

Robertson said the varying rate of growth is expected as the eruption continues with magma slowly oozing out on the surface to form the lava dome.

He added that the size of the second dome, which is located on the South Western side is such that it has begun to touch the crater walls.

“As the gas continues to be emitted, there is quite a bit of damage to vegetation on the upper part of the south west of the crater flanks and it’s beginning to extend down slope so people in Chateaubelair will begin to see that browning of the vegetation…” he said.

The professor explained that one of the effects taking place involves the gases being emitted mixing with water to form a dilute acid. This can cause things to rust more easily and vegetation to burn or die off.

However, the gases being emitted at the summit of the volcano are diluted by the time they waft to surrounding communities, which makes them less harmful to humans.

Robertson noted however that the smell can be uncomfortable, particularly for persons with respiratory problems.

As the effects of the ongoing eruption move further down the mountain slope, the geologist said UWI-SRC, NEMO and other agencies will continue monitoring the concentration of gases in the communities to see if they reach levels that may cause harm to residents.

Overall monitoring of the eruption continues as the UWI-SRC team moves to install more equipment to observe the volcano.

Already, there are monitoring stations at Wallilabou, Belmont and Georgetown.

Robertson said a pre-existing station was reactivated in Campden Park and he was on his way to Owia on Sunday with the team to install an additional one as well.

He also said that more stations will be added during the course of the week, including one at the summit, with the support of a helicopter.

The geologist advised that people should be prepared for the fact that the eruption may continue for a longer period than they would like.

“It might simply be that it continues with this kind of effusive activity where material is just coming out quietly, slowly and the risk is confined to the crater rim,” Robertson said.

“There’s a possibility that the dome will get big enough that it may start spilling over into surrounding areas and therefore will post a greater risk to lower down the valley…and finally it’s possible that it might move from being effusive to explosive.”

However, he said that the activity taking place is still in its early stages and urged persons to be prepared in the event that the worst happens.

Vincentians were also encouraged to listen to authoritative sources, NEMO and UWI-SRC for updates on the activity at La Soufriere and “make sensible decisions and not propagate rumours that don’t really help”.