Best Earth Images of the Week - July 20, 2012

Caribou Huddle

Caribou gather in Northwest Alaska to avoid insects. — (Image credit: Kyle Joly / NPS)

Humans are not the only creatures bothered by mosquitoes and flies. They harass caribou so much that earlier this month, about 300,000 of the animals huddled closely together in Northwest Alaska to avoid being bitten and parasitized.

To avoid the flying pests, caribou move inland and into higher elevations where there are fewer winged menaces. This forces them closer together in groups called aggregations, which reduces each individual's exposure in terms of relative numbers of bugs and body area open to harassment.[Full Story: Photos: 300,000 Caribou Huddle Together To Avoid Insects]

Birth of Gigantic Iceberg

Petermann Glacier's new iceberg moves toward the ocean. — (Image credit: NASA.)

A process more than a decade in the making reached its climactic moment this week, when a giant iceberg finally broke away from the floating end of a Greenland glacier and a passing satellite captured the drama on camera.

[Full Story: Photo: Giant Iceberg's Birth Snapped from Space]

Storm Socks New York

Former NFL player Dhani Jones posted this photo of a ghostly column of rain over Queens, N.Y.

Meteorologist George Wright said it looks like a rain shaft, a term meteorologists use to refer to a heavy downpour coming from a single thunderstorm. [Full Story: Photo: Strange Storm Socks New York City]

Shimmering Aurora

Aurora hangs over Concordia Station in Antarctica. — (Image credit: ESA/A. Kumar & E. Bondoux.)

The handful of wintertime residents at an isolated Antarctica research station recently got a break from austral winter's 24-hour darkness when a shimmering aurora blazed to life over their lonely outpost in the middle of the East Antarctic Ice Sheet.

[Full Story: Photo: Dazzling Aurora Appears Over Antarctic Station]

Aquarium Sees First Fur Seal Pup Birth

Northern seal pup and mother — (Image credit: New England Aquarium)

Ursula, a 14-year-old Northern fur seal, gave birth to a healthy seal pup at the New England Aquarium in Boston

[Full Story: Fur Seal Pup Birth Is Aquarium's First]