Images

A tiger swallowtail butterfly drinks nectar from a plumeless thistle flower in an abandoned agricultural field.

A zebra swallowtail butterfly drinks nectar from a plumeless thistle flower in an abandoned agricultural field.

An Eastern tiger swallowtail butterfly (female, black form) drinks nectar from a plumeless thistle flower in an abandoned agricultural field. Females have blue scales on the upper side of the lower hindwing.

South Fork of the Shenandoah River with trees and mountain in background.

Beth Stettner, USGS, demonstrates rock identification at the National Scout Jamboree.

Southern Virginia farm of Christmas trees of various types.

Libellula vibrans at rest on a blade of grass.

A USGS geologist samples spring water near a gold prospect in the Shotgun Hills, Alaska.

Texas City, Clear Lake piezos

U.S. Geological Survey Scientific Investigations Report 2018-5101

I was hiking to Mt. Cammerer in the park and got caught in a torrential thunderstorm.  On my way back to the campground, I met this view of the swollen creek and crossed by foot using hiking poles at the widest, shallowest point I could find. 

Crater Creek warm springs, Mount Spurr Volcano. Chris Waythomas measuring temperature, pH, and conductivity.

An adult great spangled fritillary butterfly rests on the strap of a backpack left in the sun at a field research station. It may have been attracted to the radiant heat or salts left behind on the strap in human sweat.

An adult great spangled fritillary butterfly rests on the arm of a chair at a field research station.

Seth Book examines ground-water discharge along the shorline of Hood Canal, WA.

Photographer Tad Pfeffer capturing images of Columbia Glacier in Prince William Sound, Alaska. He is looking down-glacier towards the ice front, which faces open water in the fjord. This open water is extremely rare, and has not happened again since 2005. The fjord is typically covered with iceberg debris, called mélange.

USGS scientists on USGS Research Vessel Musky II, deploying nets for fishing on Lake Erie.

Near Seward, Alaska

Emerald Lake is at maximum depth levels in the summer, when snowmelt from surrounding peaks feeds the lake.

Mojave Desert Tortoise found in Piute Valley in Clark County, Nevada, in
2005

Mountain big sagebrush - or Artemisia tridentata ssp. vaseyana - is a sub-species of big sagebrush that is found in primarily at higher elevation and colder, drier sites between the Rocky Mountains and the Cascades and Sierra Nevada.

Drought and beetle-killed piñon pines in Walnut Canyon National Monument near Flagstaff, Arizona, amid some surviving trees. Forest drought stress is highly correlated with mortality from poor growth, bark beetle outbreaks, and high-severity fire.