Report on Popocatepetl (Mexico) — 3 July-9 July 2013
Smithsonian / US Geological Survey Weekly Volcanic Activity Report, 3 July-9 July 2013
Managing Editor: Sally Kuhn Sennert
Please cite this report as:
Global Volcanism Program, 2013. Report on Popocatepetl (Mexico). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 3 July-9 July 2013. Smithsonian Institution and US Geological Survey.
19.023°N, 98.622°W; summit elev. 5393 m
All times are local (unless otherwise noted)
CENAPRED reported that on 3 July the seismic network detected 84 emissions from Popocatépetl. Diffuse ash plumes at 0705 and 0825 rose almost 2 km above the crater. Starting at 1742 tremor was accompanied by persistent emissions of gas and ash that rose 3.5 km. Incandescent tephra was ejected short distances onto the N and E flanks. During 3-4 July tremor and 99 emissions were detected, and incandescence from the crater was observed. Steam-and-gas plumes continued to rise above the crater and incandescent tephra was ejected onto the N and E flanks. According to news articles, multiple airlines canceled 47 flights to and from the México City (65 km NW) and Toluca (105 km WNW) airports on 4 July. Flights resumed later that day. Ash fell in areas as far as México City (70 km NW).
Gas, steam, and ash plumes drifted NW on 5 July, and almost continuous tremor was recorded. CENAPRED staff, with support of the Ministry of the Navy of México, conducted an overflight and observed continuously ejected incandescent tephra deposited at most 1.5 km away on almost all flanks, and an ash plume that rose 2 km. Cloud cover often obscured visual observations. A news article stated that four airlines canceled a total of 17 flights.
On 6 July low-frequency, high-amplitude tremor was accompanied by gas, steam, and ash emissions that rose 2 km and drifted NW. At 1330 the low-frequency tremor amplitude decreased, followed by diminishing emissions of gas and ash which drifted NW. The National Coordination of Civil Protection (CNPC) of the Ministry of Interior (SEGOB), CENAPRED, and Scientific Advisory Committee raised the Alert Level to Yellow, Phase Three. The public was reminded not to approach the crater within a 12-km radius. Later that day gas-and-ash plumes rose 3 km and drifted NW. Three explosions were detected, but cloud cover prevented visual confirmation. News articles noted ash again in parts of México City; ash accumulation was much greater in areas closer to the volcano.
During 7-9 July tremor was accompanied by persistent emissions of steam, gas, and small amounts of ash that drifted WSW and NW; cloud cover continued to hinder visual observations. Three explosions increased gas-and-ash emissions. Incandescence and ejected incandescent tephra were sometimes observed. During an overflight on 7 July, scientists observed that a new lava dome, 250 m in diameter, had recently formed in the crater. Explosions on 8 July generated ash plumes that rose 1 km and drifted NW, and explosions on 9 July generated an ash plume that rose 1.5 km and drifted SW.
Geologic Background. Volcán Popocatépetl, whose name is the Aztec word for smoking mountain, rises 70 km SE of Mexico City to form North America's 2nd-highest volcano. The glacier-clad stratovolcano contains a steep-walled, 400 x 600 m wide crater. The generally symmetrical volcano is modified by the sharp-peaked Ventorrillo on the NW, a remnant of an earlier volcano. At least three previous major cones were destroyed by gravitational failure during the Pleistocene, producing massive debris-avalanche deposits covering broad areas to the south. The modern volcano was constructed south of the late-Pleistocene to Holocene El Fraile cone. Three major Plinian eruptions, the most recent of which took place about 800 CE, have occurred since the mid-Holocene, accompanied by pyroclastic flows and voluminous lahars that swept basins below the volcano. Frequent historical eruptions, first recorded in Aztec codices, have occurred since Pre-Columbian time.