I may have bee quiet on eruption updates lately but that is far from meaning our restless Earth has been quiet. Here is some of the recent updates.
As Kilauea has been in a constant state of eruption since 1983, some don’t consider changes in activity as news. However as the June 27th lava showed us this relatively calm giant still poses a threat to people.
USGS reports suggest that the summit is still inflating; 7.5 microradians were recorded in the past week alone. Over the weekend we saw rapid filling of the Halema’uma’u crater from a depth of 90 ft from the crater rim to within 10 ft by Sunday lunch time. Yesterday (April 29th) the webcam observed small explosions and spattering with rock falls as the crater began to overflow.
Seismicity remains at an increased level towards the summit and East rift zone where wide spread breakouts from the eruption site are active as close as 8 km of Pu’u ‘O’o. There has be net inflation of Pu’u ‘O’o over the past week but not as significant as at the summit. As the June 27th Lava flows nears its 1 year anniversary incandesance indicates that surface flows remain active northeast of Pu’u ‘O’o.
Although the more explosive phase of the eruption seems to have died down, there are still high ash emissions and flight disruption is still an issue across both Chile and Argintina with ash plumes trailing to the north and south east at just over 1.5 km high. The 20 km exclusion zone is still inplace however it is belived that some people have returned to their homes within the area with maximum displaced 6,514 at the begining of this week. Seismicity has since declinded but it is still under observation.
Collapse of the lava dome on April 28th caused a pyroclastic flow to surge down the flanks. Luckily exclusion zones are still in place from activity over the past few months. The Darwin VAAC said an ash columb exceeds 14,000 ft although satalitte confirmation has not been possible due to cloud coverage.
JMA reported that 29 explosions from Showa Crater at Aira Caldera’s Sakurajima volcano ejected tephra as far as 1,300 m during 20-24 April. Nine of the explosions generated ash plumes that rose 3 km above the crater rim; one explosion, on 24 April, produced an ash plume that rose 4 km. Incandescence from the crater was visible on one night. The Alert Level remained at 3 (on a scale of 1-5). Based on JMA notices, the Tokyo VAAC reported that explosions during 22-28 April generated plumes which rose to altitudes of 1.5-4.9 km and drifted S, SE, E, NE, and N.
Moderate-to-high seismic activity at Tungurahua during 22-28 April, characterized by long-period events, tremor, and explosions. On 28 April an emission with a minor ash content rose 3 km and drifted W. Roaring was noted and lahars descended the La Pampa (NW) and Rea drainages.
During 22-28 April the seismic network at Popocatépetl recorded 25-91 daily emissions mostly consisting of water vapor and gas. Cloud cover sometimes prevented observations of the crater, although gas plumes and nighttime crater incandescence were noted daily. On 22 April an explosion at 01.21 produced diffuse gas and water vapor emissions. Explosions at 16.43 and 17.58 local time generated ash plumes. The Alert Level remained at Yellow, Phase Two.
PVMBG reported that during 1 March-21 April diffuse white plumes rose 25-50 m above Anak Krakatau, although foggy weather often prevented observations. Seismicity continued to be dominated by shallow and deep volcanic earthquakes, as well as signals indicating emissions. The Alert Level remained at .
During 17-24 April the lava dome extrusion onto Sheveluch’s N flank was accompanied by incandescence, hot block avalanches, and fumerolic activity. A thermal anomaly was detected during 16-18 and 23 April; cloud cover obscured views on the other days. The aviation code remained at Orange.