The Taftan volcanolocated inSoutheastern Iran and hitherto considered extinct, shows signs of activity well 700,000 years after its last eruption. The clues to its potential awakening were discovered by researchers from the Institute of Natural Products and Agrobiology, a research center of the Spanish National Research Council (Ipna-Csic). Their study, published in the journal Geophysical Research Lettersreveals that the area corresponding to the summit of the volcano it rose about 9 cm between July 2023 and May 2024.
Taftan, a stratovolcano of almost 4,000 metres, is located in the province of Sistan and Baluchistan, on the border between Iran and Pakistan: the uplift could be caused by a increase in gas pressure under the volcano, perhaps due to ainfiltration of magma. The discovery was made thanks toanalysis of satellite data of the Sentinel-1 mission and is fundamental because it highlights the possibility that even i volcanoes considered extinct they can resume their activities within a few months and therefore the need for a monitoring to prevent any risks for the population.
The resumption of activity of the Taftan volcano
The Taftan it is one stratovolcano 3940 m high and one of the three main magma centers located along theMakran volcanic arcwhich extends for approximately 450 km along the coasts of the Indian Ocean. This mountain range was formed due to subduction of the Arabian plate under the Eurasian plate. Taftan has had no eruptions in the last 700,000 years and was considered for this reason extinct and not dangerous for the population (a volcano is considered extinct if it has not erupted in the last 10,000 years or so). Evidence of past volcanic activity is found in the area today fumaroles which emit gas and water vapour. In 2023 the population began to report more intense gaseous emissionsthus triggering investigations by researchers. They analyzed the satellite images from ESA’s Sentinel-1 mission (European Space Agency), which they had already viewed in 2020 without identifying anomalies. This time, however, the images showed a lifting of the soil of the area at the top of the volcano. The lifting lasted ten months (from July 2023 to May 2024) and reached i 9cm. This deformation was accompanied by the increase in gas emissions felt by the population.
The causes of the uplift of the Taftan volcano
The origin of the volcano’s ground uplift has been identified at a depth of approximately 460-630 mwhere a increase in gas pressure. The cause could bealteration of the hydrothermal systemconsisting of groundwater that has infiltrated and accumulated in the rocks, where it is heated by gases of magmatic origin. This variation would have resulted in a reduction in the permeability of the rocks and the consequent accumulation of gases of magmatic origin. At the basis of the deformation of the Taftan there could also be amagma intrusionthat is, an infiltration of magma into the rocks, which would have risen from the magma chamber of the volcano located at a depth included between approximately 3.5 km and 9 km. In this way it would have heated the gases present in the overlying rocks, increasing the pressure in the pores and causing the uplift.
These studies therefore highlight the need for a careful monitoringwith the updating of volcanic hazard maps and the adoption of measures aimed at reducing volcanic risk in the area. More generally, the discovery shows how the risk posed by volcanoes believed to be extinct should not be underestimated. In this sense, the case of Taftan, although rare, is not the only one known on our planet. For example, in 2017 the Bolshaya volcano in Russiaconsidered extinct, has manifested a increase in seismic activity which would demonstrate that in reality the volcano could only be quiescent.
