Scientists flying over the volcano on March 8, 2012 noted fresh ash deposits on the east flank of the volcano near the crater, likely from an phreatic eruption on February 22. Later that day, a small ash plume erupted from the crater; by March 13, scientists detected ash deposits at the head of the Gualí River. After seismicity continued to increase, the alert level was raised to Orange, and in April Nevados National Natural Park authority closed the reserve, fearing lahars and ashfall hazards. The sudden activity peak in March did not culminate in a major eruption, and activity declined enough that the alert level was lowered to Yellow on May 3. On May 29, seismicity rapidly increased, and the alert level was restored to Orange because ash fell into more than 20 nearby communities. Over the next few months ash fell frequently until earthquakes increased again in June. Because of the severity of these tremors, evacuations were ordered by the Emergency Committee of Caldas on news media for 300–1500 people near the volcano. The alert level was raised to Red, indicating an imminent major volcanic event, and an eruption in diameter took place on July 2, 2012, continuing intermittently until the end of August. Ash plumes and sulfur dioxide emissions recurred until January 2013.