A period of increased seismic activity occurred in Yellowstone National Park on Tuesday, the two largest quakes measuring 3.1 and 2.8, according to University of Utah Seismograph Station reports.

The activity began at 3:30 p.m. and lasted about 6 hours. The two largest earthquakes occurred at 7:31 p.m. and 7:44 p.m. and were felt inside the park.

The earthquakes are the latest in an ongoing swarm in Yellowstone that began Jan. 17. So far, the largest earthquake in the swarm has been a magnitude 3.8. All told, there have been 1,719 located earthquakes in the swarm, ranging from magnitude 0.3 to 3.8.

Earthquake swarms are common in Yellowstone and the current events have still not topped the swarm of 3,000 quakes measured in 1985.

Yellowstone Volcano Observatory scientists say there is no indication the quakes are leading up to a volcanic or hydrothermal event.

Seismic information on the earthquake can be viewed at the University of Utah Seismograph Stations: www.seis.utah.edu.

Seismograph recordings from stations of the Yellowstone seismograph network can be viewed online at http://quake.utah.edu/helicorder/yell_webi.htm.

Anyone who has felt earthquakes in the swarm are encouraged to fill out a form on the USGS Community Felt reports Web site at: http://earthquake.usgs.gov/eqcenter/dyfi/.