Volcanos

Roundup of Global Volcanic Activity:

Cerro Negro de Mayasquer (Colombia): More than 11,000 micro-earthquakes at shallow depths were recorded beneath the volcanoes of Cerro Negro de Mayasquer and Chiles during the past few months, INGEOMINAS Pasto volcano observatory reported. The seismic record for Cerro Negro volcano goes only back to past November when a small network of seismometers and tiltmeters was installed, so it is not known whether the observed seismic activity is abnormal or part of the normal behavior of the volcano, which last might have erupted in 1936 and has only fumarolic activity at present. In absence of stronger signs of unrest, the alert level of Cerro Negro remains at green for the moment. The report mentions that a decrease in earthquakes was observed in the first months, while the numbers increased again this March. All quakes were tiny, not exceeding magnitude 1.2. Their hypocenters are located in a cluster a few km SE of Cerro Negro de Mayasquer and mostly between 3 and 5 km depth beneath the summit.

Ubinas (Peru): Weak ash emissions could be occurring at the volcano, recent webcam images suggest. VAAC Buenos Aires (one of the less busy VAAC centers) issued an alert in any case.

El Hierro (Canary Islands, Spain): A new swarm of earthquakes started yesterday. So far, almost 200 tiny quakes (none above magnitude 3 so far) have occurred in a broad N-S oriented area beneath the NE part of the island at around 18 km depth. A possible explanation includes a new magmatic intrusion at depth (magma accumulating at the lower crust-mantle boundary).

Kilauea (Hawai'i): (14 Mar) Spatter cones on the floor of Pu`u `O`o crater displayed persistent glow with an open lava pond within the collapsed northeast spatter cone!