Natalie M. Kehrwald, PhD
Dr. Natalie Kehrwald is a Research Geologist who investigates interactions between drought, fire, and human activity across multiple regions and timescales with the aim of providing information to land managers, communities, and the public. Understanding the conditions leading to past fires and droughts is important for planning for future scenarios in both wildland and urban settings.
Dr. Kehrwald studies interactions between water availability, fire and humans using biomarkers in ice cores and sedimentary records. Droughts and vegetation changes can affect fuel availability, and changing atmospheric conditions can alter the number of natural fire ignitions through lightning strikes. Humans are particularly adept at setting fires both for survival (cooking, warmth, and land clearance) but also often accidentally ignite wildfires. Records such as lake cores and ice cores provide detailed records of fire activity, variations in precipitation, changing vegetation and human activity through time, and help place recent droughts and wildfires into the context of a longer timescale.
See the Fire In Ice Data Visualizations created in collaboration with the USGS Vizlab under the Web Tools tab below.
Science and Products
Advancing wildfire science and technology capacity through increased DoD and USGS collaboration within an Innovation Landscapes Network
USGS scientists have teamed up with Department of Defense (DoD) in a suite of studies to innovate and demonstrate wildfire-related management strategies on military installations and DoD lands.
Fire and vegetation changes recorded in Alaskan ice cores
The past decade has comprised major fires in central Alaska and Siberia. Fire histories from ice cores in the North Pacific (Denali National Park and the Juneau Icefield) record interactions between changing temperature, precipitation, and biomass burning. We aim to quantify what vegetation burned in the past (hardwoods versus softwoods versus grasses) using ratios of levoglucosan, mannosan and...
Hydroclimate, fire, and human interactions in southwestern US tree ring records
We have identified areas of the southwestern US that do not contain paleorecords of precipitation, fire, and/or human activity. These records may be missing because, for example, lakes and forests are few and far between in much of the southwestern US. However, other sites exist that do not yet have paleorecords, but do have potential for providing lake cores and tree ring records.
Fire, human activity, and drought records in southwestern US sediments
This research aims to determine if drought, temperature variability, or human activity was the primary driver of fire activity in southwestern Colorado.
Did we start the fire? Drought, Fire and Humans
The past decade encompasses some of the most extensive fire activity in recorded history. An area the size of Vermont (~24,000 km2) burned in a single Siberian fire in the summer of 2019 (Kehrwald et al., 2020 and references therein) while Australia, Indonesia and the Amazon have all experienced their most intense fires in recorded history (van Wees et al, 2021 and references therein). As more...
Terrestrial Records of Holocene Climate Change: Fire, climate and humans
Large wildfires have raged across the western Americas in the past decade including the Las Conchas, New Mexico fire that burned 44,000 acres in a single day in 2011 (Orem and Pelletier, 2015, Geomorphology 232: 224-238, and references therein), the 2016 Fort McMurray, Alberta fire that required evacuating an entire city, and the 2015 Alaskan fire season that burned more than 5 million acres...
Science and Products
Advancing wildfire science and technology capacity through increased DoD and USGS collaboration within an Innovation Landscapes Network
USGS scientists have teamed up with Department of Defense (DoD) in a suite of studies to innovate and demonstrate wildfire-related management strategies on military installations and DoD lands.
Fire and vegetation changes recorded in Alaskan ice cores
The past decade has comprised major fires in central Alaska and Siberia. Fire histories from ice cores in the North Pacific (Denali National Park and the Juneau Icefield) record interactions between changing temperature, precipitation, and biomass burning. We aim to quantify what vegetation burned in the past (hardwoods versus softwoods versus grasses) using ratios of levoglucosan, mannosan and...
Hydroclimate, fire, and human interactions in southwestern US tree ring records
We have identified areas of the southwestern US that do not contain paleorecords of precipitation, fire, and/or human activity. These records may be missing because, for example, lakes and forests are few and far between in much of the southwestern US. However, other sites exist that do not yet have paleorecords, but do have potential for providing lake cores and tree ring records.
Fire, human activity, and drought records in southwestern US sediments
This research aims to determine if drought, temperature variability, or human activity was the primary driver of fire activity in southwestern Colorado.
Did we start the fire? Drought, Fire and Humans
The past decade encompasses some of the most extensive fire activity in recorded history. An area the size of Vermont (~24,000 km2) burned in a single Siberian fire in the summer of 2019 (Kehrwald et al., 2020 and references therein) while Australia, Indonesia and the Amazon have all experienced their most intense fires in recorded history (van Wees et al, 2021 and references therein). As more...
Terrestrial Records of Holocene Climate Change: Fire, climate and humans
Large wildfires have raged across the western Americas in the past decade including the Las Conchas, New Mexico fire that burned 44,000 acres in a single day in 2011 (Orem and Pelletier, 2015, Geomorphology 232: 224-238, and references therein), the 2016 Fort McMurray, Alberta fire that required evacuating an entire city, and the 2015 Alaskan fire season that burned more than 5 million acres...