Roundup of Global Volcanic Activity
Bezymianny (Central Kamchatka Depression): Last night, Tokyo VAAC reported an ash plume from the volcano at 20:40 UTC, based on satellite data. While it is entirely possible that activity at the lava dome of Bezymianny has picked up or that a collapse occurred which generated an ash plume, it could also be an ash plume from nearby Klyuchevskoy volcano. At the moment, the latter possibility seems more likely. Cloud cover prevented direct observation to confirm whether or not there is new activity at Bezymianny. KVERT has not issued an alert about the latter.
Cleveland (Aleutian Islands, Alaska): A recent overflight by staff of the Alaska Volcano Observatory (AVO) showed a small lava dome and active fumaroles inside the volcano’s summit crater. Incandescence could be seen at the vent of the dome, indicating that it is still active even though no explosions or other eruptive activity have taken place recently. The current aviation color code of Cleveland is yellow.
Fuego (Guatemala): The paroxysm at Fuego, which had reached its peak phase during the night of Thu-Fri (28-29 July) has ended. Starting from the early afternoon yesterday (local time), activity gradually decreased and the volcano’s activity has by now returned to intermittent smaller strombolian explosions. The lava effusion dropped as well. As of yesterday evening, the two lava flows on the SE side were still active and 1500 m long while explosions at the vent were still reaching 400 meters height; by this morning, the lava flows continued to be active, but had decreased to a few hundred of meters length and are probably going to stop soon. The recent paroxysmal eruptive phase (the 12th in 2016) with pulsating lava fountains and continuous ash emissions had lasted approx. 12 hours at its climax during the night 28-29 and morning of 29 July. It was described as one of the strongest so far this year.
Nevado del Ruiz (Colombia): Sporadic, usually small ash emissions continue to occur from time to time (every few days) such as last night (s. image attached). These explosions are likely phreatic in nature, i.e. driven by steam explosions inside the currently unstable hydrothermal system heated by an underlying magma intrusion at shallow depth. On 24 July, Washington VAAC reported a possible ash plume from Ruiz that rose to an altitude of 7.2 km (23,000 ft) a.s.l. On 26 July, an ash plume was detected that rose to an altitude of 6.9 km (22,000 ft) a.s.l. and drifted W.
Piton de la Fournaise (La Réunion): Signs that a new eruption of the volcano in the near future could be in the making have been increasing. In a bulletin yesterday, the volcano observatory (OVPF) reported elevated seismic activity, deformation and gas emissions that are consistent with the rise of magma to shallow depths. The recent seismic unrest began on 13 July; since then, OVPF recorded 163 shallow volcano-tectonic earthquakes (at depths within 2 km below the summit), including two swarms on 19 and 26 July, as well as 226 small collapses and rockfalls in the Dolomieu Crater. Also since 13 July ground inflation at Dolomieu crater (swelling of the edifice caused by magma intrusion) picked up significantly. It currently continues at rates similar to those recorded before the recent eruptions of 2015 and 2016 (rates around 1 mm distance gain / day). Last, but not least, gas measurements also show significant variations: since 21 July, a moderate increase in the average concentrations of H2S emissions has been detected from the summit – a volcanic gas released earlier than magma itself rises to the surface as the gas is very mobile and not very soluble at low pressure (shallow magma depth).
Colima (Western Mexico): Intermittent explosions continue at the volcano from time to time, but with comparably low intensity. No or little glow is visible from the volcano’s summit at night, suggesting that the magma column is relatively deep inside the conduit currently.