Chevron Canada is preparing to do 3D seismic work in the Beaufort Sea this summer as part of its oil and gas exploration program.

A lawsuit challenging petroleum exploration in Alaska's Cook Inlet was filed Tuesday by four groups, including an Alaska Native village, that claim seismic testing will harm endangered beluga whales.

Experts say a "swarm" of small earthquakes off the northwest coast of Vancouver Island are part of the normal seismic activity in the area, and they could continue for several more days.