Images

Caption: Trees tipping over and dying as ice-rich permafrost thaws in the Innoko National Wildlife Refuge, Alaska.

Thawing permafrost on various peatlands in Alaska. Permafrost thaw results in ground subsidence and inundation that kills black spruce and other understory plants living on the permafrost plateau. The black spruce forests found on permafrost plateaus are replaced with sedge- and moss-dominated bogs and fens, altering the ecosystem structure and function.

Animation of Twelvemile Lake in the Yukon Flats ecoregion in Alaska, created using USGS Landsat data.

Landslide near Potter Hill, Anchorage, Alaska, after 2018 Anchorage earthquake.

Cores were collected from various areas of thawing permafrost-peatlands in Alaska. Permafrost thaw results in ground subsidence and inundation that kills black spruce and other understory plants living on the permafrost plateau. 

A USGS scientist investigates cracks along Trunk Road in Wasilla, Alaska. Extensional crack and damage to roadway along S Trunk Rd.

A USGS scientist stands in a crack in tide flat sediment that opened during strong shaking in the November 30, 2018 Anchorage earthquake. This upland ground crack near Cottonwood Creek, Palmer Slough had horizontal displacements of ~2.5ft locally and observed maximum depth of ~3ft. The crack was observed ~150ft from the active river channel.

Exposed sand within a extensional crack along the Knik River, Alaska. Measuring a crack in sandy sediment along the south bank of the Knik River. This crack was one of many that opened across the Anchorage and Mat-Su region due to strong shaking during the M7.1 November 30, 2018 Anchorage earthquake.

Landslide from bluff below rail grade north of Rabbit Creek. Main scarp of slump/flow slide at Potter Hill. Railroad grade is to the left, tidal flat to the right. Note ponded drainage and disrupted slide material.

2018 Anchorage Earthquake

Lateral spread cracks at northern end of Port of Anchorage. These cracks were among many that opened across the Anchorage and Mat-Su region due to strong shaking during the M7.1 November 30, 2018 Anchorage earthquake.

Lateral spread cracks at the north end of the Port of Anchorage, Alaska. These cracks were among many that opened across the Anchorage and Mat-Su region due to strong shaking during the M7.1 November 30, 2018 Anchorage earthquake.

Extensional cracking and settling around private residence in Chugiak.

2018 Anchorage Earthquake

Crack observed in 2018 along headscarp of 1964 Government Hill landslide.

2018 Anchorage Earthquake

Slumping along the Alaska Railroad right-of-way evolved into long-runout landslides. The same area failed in earthquakes in 1954 and 1964.

2018 Anchorage Earthquake

Superficial slides along Eagle River east of Eagle River Loop Road. 

2018 Anchorage Earthquake

USGS scientists conduct an aerial inspection of a line of sand vents along the Cook Inlet tide flat at Earthquake Park in Anchorage. Cook Inlet coastal plain liquefaction and bluff raveling near Earthquake Park. These vents opened and ejected sand due to liquefaction triggered by strong shaking during the M7.1 November 30, 2018 Anchorage earthquake.

Minnesota Blvd off-ramp failure under repair. Construction crews rebuild the Minnesota Drive onramp in Anchorage on December 1, 2018. Engineered fill beneath the onramp failed the day before as a result of strong shaking during the M7.1 November 30, 2018 Anchorage earthquake.

Eklutna Lake dam appeared to be undamaged the day after the earthquake; overflights of the lake showed no landslides impacted the lake shoreline.

Endicott Island, and artificial island built in 1987 by Alaska Interstate Construction and is used by BP and Hilcorp Alaska for petroleum production.

Tanana River at Big Delta sonar and debris on a bridge

Tanana River at Big Delta bridge