Volcanos

Roundup of Global Volcanic Activity - New activity for the week 1 March - 7 March 2023

Aniakchak - Alaska Peninsula, Alaska : AVO reported that the earthquake swarm at Aniakchak was ongoing with 120 earthquakes located during 25 February-3 March. Magnitudes were as high as M3.1 and several earthquakes had magnitudes between M2 and M3. The earthquakes were located at shallow depths (less than 5 km) and below the S part of the caldera and to the E of the volcano. Daily, small, shallow earthquakes with magnitudes as high as M2.7 were recorded during 4-7 March.

Karangetang - Sangihe Islands : According to PVMBG the eruption at Karangetang’s Main Crater (S crater) continued during 1-7 March. Nighttime webcam images posted with daily reports showed flows of incandescent material descending the flanks, though incandescence decreased towards the end of the week.

Suwanosejima - Ryukyu Islands (Japan) : JMA reported that the number of explosions at Suwanosejima's Ontake Crater began to increase on 2 February and further increased on 2 March. Activity intensified and a total of 25 explosions were recorded during 1-5 March. Ash plumes rose as high as 1.4 km above the crater rim and large blocks were ejected as far as 500 m from the vent. Crater incandescence was visible at night. Occasional ashfall and rumbling noises were reported in Toshima village (3.5 km SSW). Explosions continued during 5-7 March. Ash plumes rose as high as 2 km above the crater rim and large blocks were ejected as far as 500 m.

Tanaga - Andreanof Islands (USA) : At 2215 on 7 March AVO raised the Aviation Color Code for Tanaga to Yellow and the Volcano Alert Level to Advisory due to increased seismicity. Earlier that afternoon, starting at about 1330, seismicity began to increase and by around 2045 earthquakes were occurring at a rate of 2-3 per minute. The events were located at shallow depths and the largest events were M2-3.

Trident - Alaska : AVO reported that the earthquake swarm at Trident was ongoing during 1-7 March. Daily small earthquakes with magnitudes less than 1 were recorded at a rate of about 1-5 per day. The Aviation Color Code remained at Yellow (the second lowest level on a four-color scale) and the Volcano Alert Level remained at Advisory (the second lowest level on a four-level scale).