A moderate earthquake shook northwest Alaska on Monday, the fifth temblor of the same magnitude since April in an area with otherwise little activity, seismologists said. The magnitude-5.7 quake struck at 4:01 a.m. Monday northeast of the village of Noatak, the Alaska Earthquake Center reported. As with other temblors in the earthquake swarm, the quake was felt in Noatak, an Inupiat Eskimo community of 560 people. […] The series of earthquakes has scientists puzzled about activity that is considered very unusual in the area. “At this point, we don’t really understand the nature of these earthquakes,” (earthquake center seismologist Natasha)...