Hawaii Volcanoes National Park closed nearly 16,000 acres on Kilauea Volcano today as the possibility for a new eruption looms over the area and surrounding communities.

Park management closed 15,688 acres near the volcano’s Puu Oo vent in the East Rift Zone, including the gravel emergency access road from the Kalapana gate to the Chain of Craters Road gate. The land makai of the emergency road is also closed to the ocean.

“The recent eruption changes and increased seismicity around the East Rift Zone and Puu Oo vent may threaten land and the community outside the park,” said Park Superintendent Cindy Orlando in a statement. “The partial closure in the park is necessary to prevent unsafe travel onto lands … and to keep people safe.”

She said most of the park remains open.

Small earthquakes continued throughout the night off of Puu Oo, prompting the U.S. Geological Survey’s Hawaiian Volcano Observatory to install additional instruments on the lower part of Kilauea’s East Rift Zone to track any changes in the surface of the volcano.

“There is clearly an intrusion of magma in the lower East Rift Zone. Not all intrusions lead to an outbreak but some do. The possibility of an eruption is very much on the table,” said spokeswoman Janet Babb.

Kua O Ka La New Century Public Charter School in Pahoa closed today and Thursday as a precaution because of the increased seismic activity.

County officials said they, along with state and federal agencies, are preparing for a possible eruption by identifying shelters, and mobilizing police and road crews to ensure public safety and evacuation routes.

Lower Puna residents should stay informed and be prepared to evacuate, they warn.

As of 10 p.m. today, the section of Pahoa-Pohoiki Road between Highway 132 (Kapoho Road) and Leilani Ave. is closed in both directions due to road damage. Detours through Highway 132 and Leilani Ave. is in place.

“Should an eruption occur, residents along the East Rift Zone may have little warning. Residents in that area should be prepared to evacuate,” said Civil Defense Administrator Talmadge Magno.

“All agencies have been alerted about the possibility of an eruption,” Magno said. “The risk areas and possible hazards are being identified, and shelters have been identified.”

Hawaii County Civil Defense was activated early Tuesday because of a surge in seismic activity and ground deformation – changes in the surface of the volcano — following the collapse of the Puu Oo crater floor on the East Rift Zone. About 200 small earthquakes occurred within a 24-hour period as of 4 p.m Tuesday.

Crews sent to check the area Tuesday did not find any evidence of ground cracks or steam. However, at least a couple of cracks formed in the roadways near Leilani Estates in Puna today, offering up the latest sign that Kilauea Volcano may be drawing closer to a new eruption.

“Overnight, earthquakes continued at a high rate in the area of the rift zone from Highway 130 eastward toward Kapoho,” according to HVO’s daily update today. “Many events were felt by residents and there have been reports of nearly constant ground vibration in some areas. … An outbreak of lava in a new location along the East Rift Zone is possible but not certain. Based on the location of current seismicity, the region downrift of Puʻu ʻŌʻō, including the area east of Highway 130, remains the most likely location should an outbreak occur.”

Babb said about 100 small temblors occurred overnight, a majority of which were 2.0-magnitude temblors with occasional 3.0-magnitude. It’s continuing to migrate to the east, she added.

Field crews installed global positioning system receivers in the lower East Rift Zone Tuesday in response to the activity. Crews are gearing up to install additional seismometers in the area today.

Everyone is encouraged to remain vigilant, Babb said.

Scientists have been detecting earthquakes and ground deformation in the rift of Puu Oo since April 21 but sudden changes occurred Monday following the collapse of the crater floor.

Hawaii County Civil Defense said Tuesday that a “magma dike,” or pathway of rising magma, is making its way down toward lower Puna past Highway 130. An eruption may take place anywhere from Puu Oo east to beyond Kapoho.

Swarms of earthquakes are being felt in the area, which could precede an eruption, said Hawaiian Volcano Observatory research geophysicist Jim Kauahikaua.

He said the current earthquake activity is similar to what preceded an eruption in lower Puna district in 1955 when at least 24 separate volcanic vents opened up and down the volcano’s East Rift Zone, with lava flows covering about 3,900 acres. Coastal communities from Kalapana to Kapoho were evacuated, and sections of every public road to the coastline were buried by lava.

Lower Puna can get more information and alerts at www.hawaiicounty.gov/active-alerts, or by signing up for automatic notices (emails or texts) about volcanic activity through the USGS Volcano Notification Service at http://volcanoes.usgs.gov/vns/.