GUATEMALA - Pacaya volcano
October 8th, 2015
INSIVUMEH reported that during 30 September-1 October and 3-6 October fumarolic plumes rose from Pacaya's Mackenney cone and drifted S. Low-frequency tremor was detected and incandescence from the crater was visible at night. Weak explosions were detected during 5-6 October. INSIVUMEH reported that during 17-19 September white-and-blue fumarolic plumes rose from Pacaya's Mackenney cone and drifted W and S. Tremor was detected and incandescence from the crater was visible at night. Weak explosions on 22 September generated an ash plume that rose 900 m above the crater and drifted W. Tremor continued to be recorded. CONRED reported that tremor at Pacaya which began on 16 June continued to be elevated at least through 18 August. INSIVUMEH reported that white-and-blue gas plumes were accompanied by a small gas emission on 1 September; the plume drifted W.INSIVUMEH reported a gradual increase of tremor amplitude at Pacaya during 17-18 June. Observers noted that small ash ejections from Mackenney cone were dispersed around the crater. Tremor continued to be detected during 20-22 June. Ash emissions continued to be confined to the crater area during 21-22 June, and incandescence from the crater was visible at night.INSIVUMEH reported that during 7-8 June white and blue fumarolic plumes rose above Pacaya's Mackenney cone. Ash emissions were observed about every 3-4 hours, and the seismic network detected signals indicating collapsed within the crater along with ash emissions.INSIVUMEH reported that during 12-13 February a series of weak explosions from Pacaya's Mackenney Crater generated dark gray ash plumes that rose 500-700 m above the crater and, along with fumarolic plumes, drifted 1.5 km S. During 14-15 February weak explosions continued to generate ash plumes; ash and fumarolic plumes drifted 800 m SE. The next day fumarolic and ash plumes drifted S and SW at a low altitude. During 16-17 February fumarolic plumes with small amounts of ash rose 100 m and drifted E. INSIVUMEH reported that during 5-10 February fumarolic plumes from Pacaya's Mackenney Crater drifted 700-800 m S and SW. In a special notice INSIVUMEH reported that on 28 January ash emissions originating from Pacaya's Mackenney Crater drifted 4 km S and SW. During field observations, scientists saw a defined central crater, 40-50 m in diameter, and ash emissions. Gas plumes rose from an area on the S flank. Seismic data was characterized by tremor and low-frequency events. In a report from 1 February, INSIVUMEH stated that low-altitude water vapor plumes with minor amounts of ash drifted W and SW. During 1-2 February fumarolic plumes rose 50 m and drifted 600 m S. In a special notice from 14 January INSIVUMEH reported that seismic data indicated weak ash emissions at Pacaya's Mackenney Crater during recent days. White and blue fumarolic plumes drifted S during 16-20 January, and seismic data continued to indicate small-to-moderate explosions. Pacaya is a complex basaltic volcano constructed just outside the southern topographic rim of the 14 x 16 km Pleistocene Amatitlán caldera. During the past several decades, activity at Pacaya has consisted of frequent strombolian eruptions with intermittent lava flow extrusion that has partially filled in the caldera moat and armored the flanks of MacKenney cone, punctuated by occasional larger explosive eruptions that partially destroy the summit of the cone