Images

The large HTHH volcanic explosion created fast low-frequency pressure waves that penetrated about 3.1 miles/5 kilometers into the shallow crust (shown in yellow). Wind and small explosions (shown in blue) create shorter pressure waves that only penetrate down about 328 feet/100 meters.

The waveforms of the ground motion recording and the pressure sensor recording from a station with both types of instruments (see second image above) match up, indicating that the pressure waves are causing the ground (crust) to deflect.

A Piper Navajo fixed-wing aircraft with rear facing stinger magnetometer. Credit: New-Sense Geophysics Limited 

An AS350 helicopter with forward facing stinger magnetometer. Credit: New-Sense Geophysics Limited 

Bear Lake, Colorado is a high alpine lake near tree line that is affected by regional to local fires and vegetation changes.

Map showing helicopter survey area and near Granby, Colo. Surveys will not occur directly above populated areas. Black circle indicates study area.

Helicopter conducting low-level flights. Image courtesy Sander Geophysics Ltd.

Loch Vale is one of 250 sites in the National Atmospheric Deposition Program/National Trends Network (NADP/NTN). Precipitation samples are collected weekly to present local and national data of pollutants and other chemicals in rain and snow since 1978.

This image shows a male bighorn sheep with large horns.                         

Male (ram - left) and female (ewe) bighorn sheep outside of Yellowstone National Park. 

Argentine black and white tegus (Salvator merianae) can survive the winter under semi-natural conditions well beyond their current invasive range.

USGS scientist assesses debris flow in Glenwood Canyon, Colorado. This post-wildfire debris flow follows the 2020 Grizzly Creek Fire. 

Interstate 70 in Glenwood Canyon, Colorado. In the summer of 2021, travelers in Colorado's Glenwood Canyon were safely evacuated before massive debris flows buried highways and destroyed bridges, thanks to a debris flow warning system developed in part by the U.S. Geological Survey.

The Grizzly Creek Fire initiated in August 2020, and widespread destructive debris flow activity followed the during the summer of 2021. This image shows damage from the summer 2021 debris flow in Glenwood Canyon, Colorado. 

Debris flow in Glenwood Canyon during the summer of 2021. This event followed the 2020 Grizzly Creek Fire in Glenwood Canyon, Colorado. 

Scientists assess post wildfire debris flow following the 2020 Grizzly Creek fire. 

Vehicles drive on interstate I-70 in Glenwood Canyon, Colorado. In the summer of 2021, travelers in Colorado's Glenwood Canyon were safely evacuated before massive debris flows buried highways and destroyed bridges, thanks to a debris flow warning system developed in part by the U.S. Geological Survey.

Photo looking downstream from the Pack Creek Road Bridge shows the rain gage on top with a USGS sticker. Below is a solar panel for power. The other white round object contains the data logger and satellite antenna.

Rain gauge installed in Glenwood Canyon, Colorado. After the 2020 Grizzly Creek fire, scientists installed a network of rain gauges and soil moisture sensors throughout the rugged burn area. These instruments provide real-time data on rainfall intensity and duration, which are critical factors in determining the likelihood of a debris flow. 

Rain gauge in Glenwood Canyon, Colorado. After the 2020 Grizzly Creek fire, scientists installed a network of rain gauges and soil moisture sensors throughout the rugged burn area. These instruments provide real-time data on rainfall intensity and duration, which are critical factors in determining the likelihood of a debris flow. 

Lahontan cutthroat trout (Oncorhynchus clarkii henshawi) is a federally listed threatened species. Ninety-seven percent of their range are small headwater streams in the Great Basin of North America.