Earthquakes struck various parts of the globe since last week, but the widespread activity was not unusual and the tremors were not related, the U.S. Geological Survey said.

"On any given day, we located about 50 earthquakes throughout the world," said Waverly Person, a USGS geophysicist. "This to us is pretty normal."

The recent quakes include:

— Alaska, magnitude 7.9, Sunday, centered 175 miles north northeast of Anchorage. No serious injuries reported. Highways had cracks 6 feet wide, the Alaska Pipeline was shut down as a precaution and home fuel tanks toppled over. The quake made lakes slosh as far away as Louisiana.

— Alaska, 6.7, Wednesday, 85 miles south of Fairbanks. No major damage or injuries.

— Nebraska, 4.3, Sunday shortly before the Alaska quake, about 30 miles west of O'Neill. Minor damage. Also felt in parts of South Dakota and Iowa.

— Southwestern Japan, preliminary magnitude estimate of 5.7, Monday. No significant damage or injuries reported. Centered 22 miles beneath the ocean floor.

— Northern Japan, 6.1, Sunday, centered 27 miles under the seabed off the coast of the northern Miyagi prefecture. One injury reported.

— South-central Italy's Molise region, aftershocks continued Monday, startling residents of an area where thousands of people have been camping out since an earthquake toppled a school and killed 29 people last week.

— Northern Pakistan, 4.5, Sunday, killing at least 10 people and injuring 48, many critically. Centered about 125 miles north of Islamabad; part of a series of quakes in the region during the weekend.

— Indonesia's Sumatra island, 7.7, Saturday, killing two people and injuring at least 40. Indonesia's Meteorology and Geophysics Agency said the quake was centered onshore. More than 4,000 people spent the night in tents and other shelters.