In a special bulletin from 0600 on 3 June INSIVUMEH noted increased activity at Fuego. Strong explosions were accompanied by rumbling sounds, and shock waves that vibrated local structures. Dense ash plumes rose 2.3 km above the crater and drifted SW, W, NW, and N. Pyroclastic flows descended the Seca (Santa Teresa) drainage on the W flank, and possibly other drainages, though poor weather conditions prevented clear views of the summit area. Ash plumes drifted in westerly directions, causing ashfall (on roofs and cars) in Sangre de Cristo (8 km WSW) and San Pedro Yepocapa (8 km NW). By 1000 pyroclastic flows were descending the Cenizas (SSW) drainage. Ashfall was reported in additional areas including La Soledad (10 km ESE), Quisache, and the municipality of Acatenango (8 km E).

Based on information from multiple agencies, the Washington VAAC reported an ash plume rising to 9 km (30,000 ft) a.s.l. at 1130 from an explosive eruption. In a report from 1340, INSIVUMEH described large pyroclastic flows traveling down the Seca, Cenizas, Mineral, Taniluya (SW), Las Lajas (SE), and Honda (E) drainages, producing dense ash plumes that rose 6.2 km above the summit (or 32,800 ft a.s.l.). A news article stated that the pyroclastic flows traveled at least 8 km and reached temperatures of 700 degrees Celsius. Tephra and lapilli fell in areas more than 25 km away, including in La Soledad, San Miguel Dueñas (10 km NE), Alotenango, Antigua Guatemala (18 km NE), and Chimaltenango (21 km NNE). Ashfall was reported as far away as Guatemala City, 70 km E. Explosions rattled structures within 20 km of Fuego. The La Aurora International Airport closed at 1415. Eyewitness accounts described the fast-moving pyroclastic flows inundating fields people were working in, overtaking bridges, and burying homes up to their roof lines in some areas. San Miguel Los Lotes, Alotenango, and El Rodeo (10 km SSE) were the worst affected.

According to Simon Carn, satellite data analysis showed that the event produced the highest SO2 loading measured from a Fuego eruption in the satellite era (since 1978), and therefore most likely the highest since the major 1974 eruption. He went on to note that the SO2 mass was about ~2 orders of magnitude than the 1974 eruption, which had a significant stratospheric impact.

At 1650 INSIVUMEH noted reports of lahars descending the Pantaleón drainage (fed by the Santa Teresa and El Mineral rivers) and other drainages. CONRED had evacuated communities near Fuego, including Sangre de Cristo, finca Palo Verde, and Panimache. At 2200 (~16.5 hours after the increased activity began), the eruption waned, with activity characterized by weak-to-moderate explosions, crater incandescence, and ash plumes that rose almost 800 m. The seismic station (FG3) recorded the last pyroclastic flow at 1845. By 0725 on 4 June seismicity had returned to normal levels. Explosions occurring at a rate of 5-7 per hour produced ash-rich plumes that rose as high as 900 m and drifted 15 km SW, W, NW, and N. Avalanches of material descended the flanks. The La Aurora International Airport reopened and flights resumed at 0930.

On 5 June INSIVUMEH reported that activity again increased. Explosions occurring at a rate of 8-10/hour, some strong, generated ash plumes that rose 5 km and drifted E and NE. At 1928 a pyroclastic flow traveled down the Las Lajas drainage. News articles noted that authorities called for another evacuation.

CONRED reported that by 0630 on 6 June a total of 12,089 people had been evacuated, with 3,319 people dispersed in 13 shelters. One bridge and two power networks had been destroyed. According to news sources on 6 June, Guatemala's National Institute of Forensic Sciences stated that 75 people were confirmed to have died and 192 were still missing. Many, possibly thousands, received burns and other injuries. Weather conditions, continuing activity at Fuego, poor air quality, hot pyroclastic flow deposits, and rain made rescue efforts difficult.

Geological Summary. Volcán Fuego, one of Central America's most active volcanoes, is also one of three large stratovolcanoes overlooking Guatemala's former capital, Antigua. The scarp of an older edifice, Meseta, lies between Fuego and Acatenango to the north. Construction of Meseta dates back to about 230,000 years and continued until the late Pleistocene or early Holocene. Collapse of Meseta may have produced the massive Escuintla debris-avalanche deposit, which extends about 50 km onto the Pacific coastal plain. Growth of the modern Fuego volcano followed, continuing the southward migration of volcanism that began at the mostly andesitic Acatenango. Eruptions at Fuego have become more mafic with time, and most historical activity has produced basaltic rocks. Frequent vigorous historical eruptions have been recorded since the onset of the Spanish era in 1524, and have produced major ashfalls, along with occasional pyroclastic flows and lava flows.

Sources: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e Hidrologia (INSIVUMEH), Coordinadora Nacional para la Reducción de Desastres (CONRED), Washington Volcanic Ash Advisory Center (VAAC), Simon Carn, NASA Earth Observatory, BBC News, The Guardian News, ABC News - American Broadcasting Corporation, U.S. Embassy in Guatemala