Gisenyi, Rwanda | Wednesday
DEADLY earth tremors shaking central Africa’s Lake Kivu region in the aftermath of last week’s volcanic eruption have scientists baffled over their nature, origin and epicentre.
They have not determined how the quakes which have claimed several lives and destroyed hundreds of buildings are related to the volcanic activity that sent a river of lava spewing from Mount Nyiragongo into the town of Goma in the east of the Democratic Republic of Congo (DRC).
The lava flattened tens of thousands of buildings in Goma and prompted a massive international humanitarian response.
But the incessant earthquakes are wreaking their own damage and posing new concerns.
A senior UN official said on Tuesday that the quakes had claimed several lives, “less than 10,” around Gisenyi, a Rwandan town that lies adjacent to the DRC’s Goma.
Rwandan officials said that nearly 300 buildings and 19 schools had been destroyed.
Considerable damage was also reported in the DRC town of Katale, said Dieudonne Waffula, a vulcanologist who has long been studying Nyiragongo.
“There was one (earthquake) in the morning that woke people up,” according to Waffula.
Aside from that dramatic quake, less serious but nevertheless disconcerting shocks were felt late Tuesday and Wednesday morning.
“We have not yet determined the epicentre” of the quakes, said the volcano expert, who is currently working with several colleagues from France, Italy and Switzerland.
“They seem to be heading eastwards, because when I called someone in Ruhengeri (a Rwandan town 50 kilometres east of Gisenyi) he felt it a few seconds after we did” in Goma, Waffula said.
“It was also felt very strongly in Bukavu,” 100 kilometres south of Goma and also on Lake Kivu.
Waffula voiced doubt over reports of another volcanic eruption on Tuesday night, at the nearby Mount Nyimuragira.
“We had a look at both of them (Nyimuragira and Nyiragongo) yesterday afternoon. There was nothing. We are waiting for the helicopters to look again and when we determine what is going on, we will make a full report,” he said.
The reported eruption of Nyimuragira was not thought to pose a threat to Goma or Gisenyi.
Waffula also explained that the previously molten centre of the encrusted lava flow that cuts Goma in two was now hardening and that less lava was falling into Lake Kivu, just south of the town, than before.
As a result, he said, chances were diminishing that the lava would react with dissolved methane and carbon dioxide at the deep bottom of the lake, an eventuality that might send these gases to the surface.
Carbon dioxide, being heavier than oxygen, could then settle over populated areas, asphyxiating residents.
Some 1 800 people died in their sleep in this way around Cameroon’s volcanic Lake Nyos in 1986.
But vulcanologists have pointed out that Lake Kivu is much deeper and larger than Nyos, and that it would take far greater quantities of lava flowing much faster into the lake to provoke such a catastrophe here.
“It is impossible, unless there is a massive earthquake in the lake, which would turn the water upside down, freeing the methane and carbon dioxide,” explained Wafulla, adding that the quakes were not centred under the lake. – AFP