Images

The new eruption at the summit of Kīlauea volcano on September 10, 2023. After about an hour of increased seismic activity and uplift, HVO scientists observed the start of the eruption at approximately 3:15 p.m. HST.

The new eruption at the summit of Kīlauea volcano on September 10, 2023. After about an hour of increased seismic activity and uplift, HVO scientists observed the start of the eruption at approximately 3:15 p.m. HST.

The new eruption at the summit of Kīlauea volcano on September 10, 2023. After about an hour of increased seismic activity and uplift, HVO scientists observed the start of the eruption at approximately 3:15 p.m. HST.

The new eruption at the summit of Kīlauea volcano on September 10, 2023. After about an hour of increased seismic activity and uplift, HVO scientists observed the start of the eruption at approximately 3:15 p.m. HST.

The new eruption at the summit of Kīlauea volcano on September 10, 2023. After about an hour of increased seismic activity and uplift, HVO scientists observed the start of the eruption at approximately 3:15 p.m. HST.

The new eruption at the summit of Kīlauea volcano on September 10, 2023. After about an hour of increased seismic activity and uplift, HVO scientists observed the start of the eruption at approximately 3:15 p.m. HST.

The new eruption at the summit of Kīlauea volcano on September 10, 2023. After about an hour of increased seismic activity and uplift, HVO scientists observed the start of the eruption at approximately 3:15 p.m. HST.

Screen shot visualization of wind direction and velocity from a coupled/fire atmosphere model run of a wildfire (Dude Fire).

Cover image for the video Natural Hazards We Might Face, in support of National Preparedness Month.

Things to know about ShakeAlert graphic that shows the limitations of earthquake early warning.

Animated GIF of a cobbled streambed along the Elwha River in Washington State, from The Elwha River: Landscapes of Recovery Geonarrative 

TYPES OF LANDSLIDES

Lateral spreads are distinctive because they usually occur on very gentle slopes or flat terrain. The dominant mode of movement is lateral extension accompanied by shear or tensile fractures.

Creep is the imperceptibly slow, steady, downward movement of slope-forming soil or rock. Movement is caused by shear stress sufficient to produce permanent deformation, but too small to produce shear failure.

Debris avalanche: This is a variety of very rapid to extremely rapid debris flow.

A debris flow is a form of rapid mass movement in which a combination of loose soil, rock, organic matter, air, and water mobilizes as a slurry that flows downslope. Debris flows include <50% fines.

Toppling failures are distinguished by the forward rotation of a unit or units about some pivotal point, below or low in the unit, under the actions of gravity and forces exerted by adjacent units or by fluids in cracks.

Rockfalls are abrupt movements of masses of geologic materials, such as rocks and boulders, which become detached from steep slopes or cliffs. Separation occurs along discontinuities such as fractures, joints, and bedding planes, and movement occurs by free-fall, bouncing, and rolling.

Earthflows have a characteristic "hourglass" shape. The slope material liquefies and runs out, forming a bowl or depression at the head. The flow itself is elongated and usually occurs in fine-grained materials or clay-bearing rocks on moderate slopes and under saturated conditions. However, dry flows of granular material are also possible.

A block slide is a translational slide in which the moving mass consists of a single unit or a few closely related units that move downslope as a relatively coherent mass.

Translational slide: In this type of slide, the landslide mass moves along a roughly planar surface with little rotation or backward tilting.