Volcanos

Roundup of Global Volcanic Activity - Ongoing activity for the week 1 February - 7 February 2023

Ahyi - Mariana Islands (USA) : Unrest at Ahyi Seamount continued during 31 January-7 February. Pressure sensors on Wake Island, 2,270 km E of Ahyi Seamount, detected activity during 31 January-1 February and possible activity during 4-6 February. Plumes of discolored water were not identified satellite images, though the image resolutions were too low to detect it.

Aira - Kyushu (Japan) : JMA reported ongoing eruptive activity at Minamidake Crater (at Aira Caldera’s Sakurajima volcano) during 30 January-6 February and crater incandescence was visible nightly. Sulfur dioxide emissions were high at 2,000 tons per day on 30 January. An explosion at 1951 on 3 February produced an ash plume that rose 1.2 km above the crater rim and ejected large blocks as far as 500 m from the crater.

Cotopaxi - Ecuador : IG reported that the eruption at Cotopaxi continued during 1-7 February, characterized by daily emissions of gas, steam, and ash emissions; inclement weather conditions occasionally prevented views. Gas-and-steam emissions were visible rising from the crater on 1 February. Seismicity increased at 0100 on 2 February and was associated with an ash plume that rose 1.3 km above the summit and drifted NW. Later that day emissions containing ash rose as high as 2.5 km and drifted N, NE, and SE. Ashfall was reported in the N part of Parque Nacional Cotopaxi, and in the area of the Tesalia (47 km NNW) and Güitig factories. Ashfall was also reported in the Quito and Mejía regions including in Amaguaña (35 km NNW), Quitumbe (43 km NNW), Conocoto (41 km N), Guamaní, La Ecuatoriana (44 km NNW), Turubamba (43 km NNW), Chillogallo (47 km NNW), La Magdalena, Machachi (24 km NW), Tambillo (32 km NNW), Alóag (28 km NW), and Cutuglahua (35 km NNW). On 3 February ash plumes rose as high as 2.5 km and drifted in multiple directions, and ash fell in Amaguaña, La Armenia, Quitumbe, Conocoto, Guamaní, La Ecuatoriana, Turubamba, Chillogallo, La Magdalena, Machachi, Tambillo, Alóag, Cutuglahua, Uyumbicho (30 km NNW), Aloasí (24 km NW), and El Chaupi (24 km WNW). On 4 February ash plumes rose 1.5 km and drifted NNE and SE. Ashfall was noted in Guamaní, Turubamba, Chillogallo, La Ecuatoriana, Quitumbe, Tambillo, Machachi, Aloasí, Aloag, and Conocoto. On 5 February steam-and-gas emissions with low ash content drifted NW. In the afternoon ash emissions rose 200 m and drifted S. Minor gas emissions were visible during 6-7 February.

Ebeko - Paramushir Island (Russia) : KVERT reported that moderate activity at Ebeko was ongoing during 26 January-2 February. According to volcanologists in Severo-Kurilsk (Paramushir Island, about 7 km E) explosions during 28-29 and 31 January and 1 February generated ash plumes that rose as high as 4 km (13,100 ft) a.s.l. and drifted NE. A thermal anomaly was identified in satellite images on 31 January.

Etna - Sicily (Italy) : INGV reported that the vents at the NE base of Etna’s SE Crater, in the Valle del Leone at about 2,800 m elevation, continued to feed lava flows during 30 January-5 February. The flow rate was highly variable with an increase on 1 February, a gradual decrease overnight during 1-2 February, and a complete cessation on the morning of 2 February. Later, during the afternoon of 2 February, lava again effused from the vent and traveled over pre-existing flows. The effusion rate started to decrease in the afternoon of 4 February and progressively decreased overnight into 5 February. By the afternoon of 5 February, the flows appeared to be cooling. Intense gas emissions rose from Bocca Nuova Crater while gas emissions at Northeast Crater (NEC) and Voragine were minimal. Activity at Southeast Crater was characterized by fumarolic activity localized along the crater rim and from the May-June 2022 eruptive vent which also occasionally produced flashes of incandescence at night. Occasional diffuse ash emissions were also visible and rapidly dispersed with the wind.

Fuego - South-Central Guatemala : INSIVUMEH reported that 4-12 explosions per hour were recorded at Fuego during 31 January-6 February, generating ash plumes that rose as high as 1.1 km above the crater rim and drifted as far as 20 km SW, WSW, and W. Ashfall was recorded during 2-4 February in areas downwind including Morelia (9 km SW), Panimaché I and II (8 km SW), Santa Sofía (12 km SW), El Porvenir (8 km ENE), San Pedro Yepocapa (8 km NW), and Finca Palo Verde. Daily block avalanches descended various drainages including the Ceniza (SSW), Seca (W), Trinidad (S), Taniluyá (SW), Honda, Las Lajas (SE), and El Jute (ESE), and often reached vegetated areas. Daily shock waves rattled structures in communities around the volcano and rumbling was often heard. Explosions ejected incandescent material 100-200 m above the summit each day. Resuspend ash deposits from high winds during 3-4 February formed “curtains” of ash on the S flank.

Great Sitkin - Andreanof Islands (USA) : AVO reported that seismicity at Great Sitkin was low during 1-7 February. No activity was observed, though weather clouds obscured satellite and webcam views.

Kerinci - Central Sumatra : PVMBG reported that the eruption at Kerinci was ongoing during 1-7 February. An eruptive event was recorded at 0230 on 3 February but was not visually confirmed. White-and-gray ash plumes were visible later that day rising 100 m above the summit and drifting NE and E. At 0646 on 4 February a gray-to-brown ash plume rose 200 m and drifted E and SE. At 0722 on 5 February a dense brown ash plume rose 200 m and drifted NE and E. White-and-brown emissions rose as high as 150 m on 7 February.

Kilauea - Hawaiian Islands (USA) : HVO reported that lava continued to erupt on Kilauea’s Halema’uma’u Crater floor during 1-7 February. Activity was concentrated in the E half of the crater in a large, perched lava lake with well-defined levees, covering about 10 hectares. A smaller lake to the W was active in the basin of the 2021-2022 lava lake. Part of the E lake began to crust over on 1 February, forming a crusted isthmus through the center of the lake and two smaller areas of lava on the N and S sides. The lava fountain was located on the S side. Lava in each of the two smaller areas independently circulated in opposite directions from each other. At around 2315 lava fountaining ceased but resumed about 45 minutes later, rising 1-2 m. During 0100-0400 on 2 February lava from the S side flooded across the whole E lake, covering the isthmus, and returning the E lake to the size it was (10 hectares). The W Lake, and two smaller lava ponds in the central and S portions of the crater floor, remained relatively stable, though one of the ponds overflowed. Two small floating islands in the E lake sank during 2-3 February. During 2-7 February the E lake, the W lake, and the two small lava ponds remained active and stable. The lava fountain continued to be active, though during 4-5 February bursts of activity caused the fountain to double in height. A second small lava fountain was temporarily active near the first fountain during 0300-0700 on 5 February. Starting at around 2100 on 5 February through 0900 on 6 February a large breakout occurred on the N portion of the crater floor covering an area equal to or slightly larger than the E lava lake. A smaller breakout S of the E lake occurred around 0000 on 6 February. The large breakout continued to be active on 6 February but was only weakly active by 7 February.

Lewotolok - Lembata Island : PVMBG reported that the eruption at Lewotolok was ongoing during 1-7 February. Incandescence above the crater was visible in a 1 February webcam image. White-and-gray plumes rose as high as 400 m above the crater rim and drifted E and SE on 1 and 5 February. White plumes of variable densities were visible on other days of the week.

Marapi - Central Sumatra : PVMBG reported that the eruption at Marapi continued during 1-7 February. White-and-gray emissions rose as high as 200 m and drifted in various directions during 1-2 and 4 February; white steam plumes were visible on 3 February. White-and-brown plumes rose as high as 400 m on 6 February. Weather clouds sometimes prevented views of the volcano.

Merapi - Central Java : BPPTKG reported that the eruption at Merapi continued during 27 January-2 February and seismicity remained at high levels. The SW lava dome produced six lava avalanches that traveled as far as 1.8 km down the SW flank (upstream in the Kali Bebeng drainage); occasional avalanche sounds were recorded. No significant morphological changes to the central and SW lava domes were evident in webcam images. At 0710 on 8 February a pyroclastic flow traveled 1.5 km down the Boyong drainage on the SW flank. Ashfall was reported in areas downwind including Sangup, Musuk, and Mriyan.

Santa Maria - Southwestern Guatemala : INSIVUMEH reported that the eruption at Santa María’s Santiaguito lava-dome complex continued during 31 January-6 February. Effusion from Caliente cone fed lava flows that descended the San Isidro and Zanjón Seco drainages on the W and SW flanks; the longest part of the lava flow was 4.4 km on 15 January. Incandescence from the dome and the lava flows was visible nightly. Block-and-ash flows from the dome, and from both the ends and sides of the flows, descended the S, SW, and W flanks almost daily. “Curtains” of ash sometimes rose several hundred meters along their paths. Explosions were generally weak-to-moderate in size and produced gas-and-steam plumes with minor amounts of ash that rose several hundred meters above the complex. Explosions and accompanying rumbling were heard in El Palmar (12 km SSW) during 3-4 February. Ashfall from both explosions and block-and-ash flows was reported in the Monte Claro (S), El Faro, and La Florida (6 km S), Santa Marta, and El Viejo Palmar (11 km S) ranches during 3-4 February.

Semeru - Eastern Java : PVMBG reported that the eruption at Semeru continued during 1-7 February. White-and-gray ash plumes that were somewhat dense rose 300-700 m above the summit and drifted N, NE, S, and SW. One of the ash plumes, recorded at 0729 on 1 February, was a dense white-and-gray plume that rose 700 m and drifted NE. At 0700 on 2 February an ash plume rose 600 m and drifted NE. On 3 February white-and-gray plumes rose 100-300 m and drifted S, SW, W, and N. An eruptive event at 1242 on 5 February produced a white, gray, and brown ash plume that rose around 1.5 km and drifted N. Webcam images showed a pyroclastic flow descending the SE flank and ash plumes rising its path. The Alert Level remained at 3 (on a scale of 1-4). The public was warned to stay at least 5 km away from the summit, and 500 m from Kobokan drainages within 17 km of the summit, along with other drainages originating on Semeru, including the Bang, Kembar, and Sat, due to lahar, avalanche, and pyroclastic flow hazards.

Semisopochnoi - Aleutian Islands (USA) : AVO reported that eruptive activity at Semisopochnoi’s Mount Young continued during 1-7 February. Seismicity was elevated and daily weak tremor was recorded. Minor steam emissions were visible in webcam images during 3-7 February.

Sheveluch - Central Kamchatka (Russia) : KVERT reported that the ongoing eruption at Sheveluch during 26 January-2 February was generally characterized by explosions, hot avalanches, lava-dome extrusion, and strong fumarolic activity. A persistent thermal anomaly was identified daily in satellite images, and minor ash plumes from explosions and lava-dome collapses drifted 70 km NE on 27 and 31 January and 2 February.

Suwanosejima

Ryukyu Islands (Japan)

JMA reported that the eruption at Suwanosejima's Ontake Crater continued during 30 January-6 February with a total of seven explosions recorded by the seismic network. The explosions produced eruption plumes that rose as high as 1.5 km above the crater rim and ejected large blocks as far as 400 m from the vent. Crater incandescence was observed nightly. Occasional ashfall and rumbling noises were reported in Toshima village (3.5 km SSW).