OVSICORI-UNA reported an explosion at Turrialba on 10 May, followed by weak and passive ash emissions during 10-11 May.
Several long-period earthquakes were recorded, and inflation continued.
Gas measurements indicated a sulfur dioxide flux of 1,000 tons/day, and a high carbon dioxide/sulfur dioxide ratio.
An event at 0900 on 12 May generated a plume, though poor visibility prevented a height estimate.
An event at 0730 on 14 May generated a plume that rose 500 m above the crater rim and drifted N.
Low-amplitude tremor was detected during 15-16 May, and a discontinuous ash plume rose no more than 500 m and drifted N and NW.
Source: Observatorio Vulcanologico y Sismologico de Costa Rica-Universidad Nacional (OVSICORI-UNA)