El Salvador Volcano May Erupt Again Soon, Foreshadowed by High Gas Emissions [VIDEO]

Officials in El Salvador remain on alert as the San Miguel volcano continues to emit gasses at rates which may be indicative of another eruption.

When San Miguel - also known as Chaparrastique - erupted unexpectedly the morning of Dec. 29, officials ordered the evacuation of villages within a 3 kilometer range of the summit as gas and ash shot about 5,000 meters in the air. Thousands of people initially evacuated, but many of them have returned to their homes in the days following the eruption because of an apparent lack of volcanic activity.

There have been no new eruptions on Chaparrastique since Sunday, but there has been a surge in the emission of sulfur dioxide, estimated at about 2,800 tons per day, which officials warn could be a sign of another eruption. If the volcano erupts again, officials with the Salvadorian environment ministry suggest a lava flow will come along with the eruption. Sunday's eruption resulted in gas and ash emissions and only a small pyroclastic flow.

More than 2,000 people were ordered to evacuate the mountainside when Chaparrastique erupted, but nearly half of them have gone against official advice and returned to their homes, according to the BBC.

An additional 3,000 people were ordered to evacuate from the cities of San Miguel, San Jorge, San Rafael Oriente, and Chinameca, the volcano news website Volcano Discovery reported Thursday.

Following Sunday's eruption, heavy ash fell upon nearby areas downwind, such as in the towns of Chinameca and San Jorge to the volcano's west.

An analysis of the ash from the Dec. 29 eruption revealed it to be 80 percent juvenile material, which means it was created from new magma. The juvenile material is indicative that a new magma batch has risen inside the volcano and could lead to new activity in the near future, Volcano Discovery reported.

Additional analysis revealed the "absence of crystals in the juvenile glass matrix of the ash indicates that the magma rose quickly, i.e. without having time to form crystals. That further adds to the need to stay on alert, because a sudden eruption might just happen again."

Sunday was the first major eruption of Chaparrastique in 37 years. There have been no reports of serious injuries or damage. Two people were reportedly treated at a local hospital for respiratory problems apparently linked to the volcanic eruption.

"We are providing assistance to people evacuating, and we are asking them to protect themselves against the gases, which can affect the respiratory tract," Assistant Health Minister Eduardo Espinoza said, according a report by The Associated Press.

The volcano, a 7,025-foot (2,129-meter) stratovolcano, is located about 15 kilometers southwest of the city of San Miguel, one of the largest cities in El Salvador. The eruption occurred about 145 kilometers east of San Salvador, the nation's capital.

El Salvador's Ministry of Environment and Natural Resources reported the eruption began Sunday at 10:30 a.m., according to a CNN report.

The last significant eruption of Chaparrastique was in 1976.