NASA satellite imagery has captured the thermal signature of volcanic activity in Iceland's Reykjanes peninsula. Following an eruption that occurred in late 2021 and led to residential evacuations, new fissures have now opened near the town of Grindavík, releasing lava over a span of 48 hours. Despite barriers constructed in the area to divert the flow away from the town, volcanic activity continues to pose a risk.

These recent eruptions on the Reykjanes peninsula mark the fifth time volcanic activity has occurred since 2021. NASA's Landsat 9 satellite, equipped with the Thermal Infrared Sensor 2 (TIRS-2) instrument, has been monitoring the hazardous activity from above and collecting crucial data. TIRS-2 utilizes two different wavelengths to detect thermal radiation, pinpointing areas of intense heat where lava flow emerged earlier this month.

Data collected by TIRS-2 on January 16, as Landsat 9 passed overhead, has been superimposed over a digital elevation model of the affected region, providing valuable insights into the concentrated volcanic activity. The imagery, provided by NASA's Earth Observatory, reveals central warm regions shown in yellow, with lighter temperatures and cloud coverage represented in light blue.

The recent eruptions followed a series of events that began with a powerful seismic swarm on December 18, 2021. This was followed by a volcanic fissure eruption on Sundhnúkagígaröðin, located east of Mt. Sýlingarfell, which prompted the evacuation of approximately 4,000 residents from Grindavik.

Since then, volcanic activity has persisted, with the latest eruption occurring on January 14, 2024, just one kilometer away from Grindavík. Despite the barriers put in place, an additional fissure opened outside of the protective barrier, resulting in lava flows that reached three homes on the outskirts of the town.

Fortunately, the volcanic activity subsided within 48 hours, according to the Icelandic Meteorological Office. Past efforts to prevent lava destruction have involved using millions of tons of sea water to cool the lava and protect homes and infrastructure. Currently, magma movements beneath the region have caused uplift and deformation of the surrounding Earth.

The Icelandic Met Office provided an update on January 19, noting clear signals of continued land uplift beneath Svartsengi. However, more time is needed to determine if the rate of land uplift has increased since the eruption on January 14.

Seismic activity in the area is decreasing overall, and data suggests a significant slowdown of ground movement compared to previous days. The Met Office believes this may indicate that the magma is no longer flowing into the dyke and that the eruption has come to an end.

While the situation remains monitored, residents in the affected region can find some relief as the volcanic activity wanes. The data collected by NASA's satellite imagery and the ongoing monitoring efforts by the Icelandic Meteorological Office provide vital information for assessing the situation and ensuring the safety of those living nearby.