— CDC to develop earthquake response plan with affected Rupununi communities

LESS than two months after an earthquake struck Region Nine (Upper Takutu – Upper Essequibo) and other parts of Guyana, another earthquake, pegged at a magnitude of 4.7, rattled the southern area of Region Nine on Friday.

At around 13:00 hours, the Guyana Chronicle received reports from the ‘Deep South’ Rupununi community of Katoonarib that an earthquake was felt in the community. According to the community’s Deputy Toshao, Floria Singh, the vibrations lasted for about a minute. “We were at a women’s meeting and we had to run out of the building,” the Deputy Toshao said, adding: “It happens in the nights also but not really as strong as this one.”

On January 31, a 5.7 magnitude earthquake struck Guyana and was felt across the country and in parts of Brazil. The communities of Aishalton, Katoonarib and Sawariwau were severely affected, with buildings and earth surfaces here damaged. Since then, tremors continued to affect communities in the southern area of Region Nine, causing concerns with the residents there.

On Friday, however, Region Nine did not experience another tremor but a full-blown earthquake. With its magnitude of 4.7, this earthquake is still relatively small, according to the Richter scale that characterises earthquakes.

This earthquake was later confirmed by the Civil Defence Commission (CDC)’s acting Preparedness and Response Manager, Major Salim October. “We’re waiting on additional information to come from the region but so far there has not been any reported damage or any effects apart from the communities experiencing those shocks,” he told the Guyana Chronicle in a telephone interview on Friday afternoon.

CAUSE FOR CONCERN

The Major noted that any earthquake — no matter how minor — is a cause for concern. He explained that Guyana sits on the shelf of a tectonic plate, which is a relatively stable region that is not necessarily prone to such natural disasters. There are some concerns, however, as to why these earthquakes and tremors continue to occur here.

Recently, a multi-stakeholder team installed equipment to monitor seismic activity in four different locations in the south Rupununi area: one close to the epicentre of the earthquake (located somewhere near Katoonarib), and three in surrounding areas, thereby creating a seismic monitoring network.

Professor at the São Paulo University, Marcelo Sousa de Assumpção, who has been working with the team, explained in a recent virtual meeting that most of the aftershocks (or tremors) will occur in the same faults where the original earthquake occurred. These aftershocks can be used to study the properties and the geology of the main shock (the January 31 earthquake).

The professor further explained that an earthquake occurs when the rocks or faults on the earth’s crust can no longer sustain the stress (or pressure) that it has been experiencing for a very long time. At that point, there is a sudden movement, known as a failure, that generates a very strong vibration.

He explained that sometimes, some parts of the fault may still have some stress to release, thereby resulting in the aftershocks. And this has been the case in the ‘Deep South’ area, where the fault running across the region has been releasing these aftershocks.

“The seismometers that are deployed are supposed to be doing all the different analyses to determine whether there is a fault line anywhere in the area and to measure whether there is escalation or de-escalation in the tremors,” Major October also said on Friday.

EARTHQUAKE RESPONSE PLAN

Nevertheless, the Major highlighted that the CDC is working on a medium to long term plan to help the affected communities respond to these largely unpredictable occurrences. “At the moment, the CDC is gonna be looking at a more medium to long term process which will include Katoonarib and Sawariwau in the community-based risk-management system,” he said, emphasising: “We will commence discussions with those communities with the aim of developing community-specific plans and we will be working with them to develop an earthquake response plan which forms the basis of an annex to their recent disaster risk management system.”

He noted that there is no timeline guiding the development of this plan as yet but hastened to add that such a response is needed in the fastest possible time. In the interim, he noted that data from the seismometers is retrieved every week by the Guyana Geology and Mines Commission (GGMC). The monitoring through this setup is still in its embryonic stage but the country’s partners at the University of Sao Paulo have been interpreting and analysing the readings.