Any drop in USGS activity would impact lesser developed nations such as the Philippines, which run smaller-scale monitoring and rely on the USGS for global earthquake data, Robert Geller, a professor of seismology at Tokyo University, said by phone. It would also affect ordinary citizens in the U.S, he said.

"If a big quake occurred now, hypothetically, inside the U.S., disaster relief work might be slowed down if USGS data wasn't available to the government," Geller said. The effect of the shutdown depends on whether the agency has curtailed the monitoring itself or stopped putting the data online, he said.

Earthquake Risk

Despite the warning, the National Earthquake Information Center of the USGS at Golden, Colorado, does not expect delays in earthquake monitoring and said data is being gathered at the same rate as before the shutdown. "At this point we are getting earthquakes posted on our website on time, within 20 minutes for magnitude 5 and larger worldwide, and earlier for a national event," Jana Pursley, a geophysicist at the center, said today in a phone interview.

The partial shutdown of the U.S. federal government began Oct. 1 after Republicans insisted on changes to the 2010 Patient Protection and Affordable Care Act. President Barack Obama and Democrats refused.

Earthquakes pose significant risk to 75 million Americans in 39 States, according to the USGS website. The USGS is the only federal agency responsible for recording and reporting earthquake activity in the country and its accurate and timely information is used by citizens, emergency responders, and engineers, according to the website.

At least 67 people were killed in the Philippines as a result of the strongest earthquake to hit the nation in a year. The magnitude-7.2 earthquake struck 2 kilometers (1.2 miles) south of Carmen, Bohol at 8:12 a.m. local time, according to the USGS.