Cotopaxi Developments
The Instituto Geofisico (IG) issued a special report on 21/03/23 outlining changes in the current eruptive period at Cotopaxi, which began on October 21, 2022. There is evidence of declining volcanic activity, with a decrease in monitoring parameters within the volcanic system and at the surface.
Ash Emissions
During the current eruptive period, the most common volcanic product has been ash emissions, which were most intense between December 2022 – February 2023, averaging ten events per week. In comparison, the week of March 13 – March 20 recorded only two ash emissions. The current rate is less than one event every two days.
Seismicity
The fragmentation of magma involves in ash emissions causes seismic tremors which are recorded. The current downward trend in seismicity at Cotopaxi is indicative of a decrease in internal movement and magma fragmentation at depth.
Ash Fall
The Washington Volcanic Ash Warning Centre (W-VAAC) reported 135 ash clouds since October 21, 2022, with a range of up to 100 km and heights up to > 1.5 km above the crater. The estimated mass of ashfall from Feb 14-March 14 is 100 million kg. This figure represents a 50% decrease from the previous period (Jan 17 – Feb 14).
Degassing
Current emissions are now mostly associated with volcanic degassing, made up of gas and water vapor which do not generate comparable tremors to ash emission. Plumes associated with degassing has not showed a decrease in incidence, maintaining average heights of 500 – 1000 m above the summit.
Deformation
As magma enters a volcanic system, pressure increases and stress states change, manifesting at the surface as ground deformation. Inflation began in July 2022 and continued until mid-January 2023. As of February 2023, a change in trend is observed from upward, to stable, indicating deflation may soon commence.
The IG states there is no evidence of a greater volume of magma entering the volcanic system and that the current eruption is decreasing in intensity.
In the short term, the downward trend in volcanic activity is expected to continue, associated with VEI 1 (volcanic explosivity index) hazard scenario.
Nevertheless, due to the nature of volcanic phenomena, a change in trend from decreasing to increasing cannot be ruled out. A decrease in eruptive frequency and intensity does not decrease the need to surveillance of the volcanic system.
Cotopaxi remains in Yellow Alert (the second lowest on a four-colour scale).
Source: Instituto Geofisico
Ash Emissions
During the current eruptive period, the most common volcanic product has been ash emissions, which were most intense between December 2022 – February 2023, averaging ten events per week. In comparison, the week of March 13 – March 20 recorded only two ash emissions. The current rate is less than one event every two days.
Seismicity
The fragmentation of magma involves in ash emissions causes seismic tremors which are recorded. The current downward trend in seismicity at Cotopaxi is indicative of a decrease in internal movement and magma fragmentation at depth.
Ash Fall
The Washington Volcanic Ash Warning Centre (W-VAAC) reported 135 ash clouds since October 21, 2022, with a range of up to 100 km and heights up to > 1.5 km above the crater. The estimated mass of ashfall from Feb 14-March 14 is 100 million kg. This figure represents a 50% decrease from the previous period (Jan 17 – Feb 14).
Degassing
Current emissions are now mostly associated with volcanic degassing, made up of gas and water vapor which do not generate comparable tremors to ash emission. Plumes associated with degassing has not showed a decrease in incidence, maintaining average heights of 500 – 1000 m above the summit.
Deformation
As magma enters a volcanic system, pressure increases and stress states change, manifesting at the surface as ground deformation. Inflation began in July 2022 and continued until mid-January 2023. As of February 2023, a change in trend is observed from upward, to stable, indicating deflation may soon commence.
The IG states there is no evidence of a greater volume of magma entering the volcanic system and that the current eruption is decreasing in intensity.
In the short term, the downward trend in volcanic activity is expected to continue, associated with VEI 1 (volcanic explosivity index) hazard scenario.
Nevertheless, due to the nature of volcanic phenomena, a change in trend from decreasing to increasing cannot be ruled out. A decrease in eruptive frequency and intensity does not decrease the need to surveillance of the volcanic system.
Cotopaxi remains in Yellow Alert (the second lowest on a four-colour scale).
Source: Instituto Geofisico
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