Natalie Kehrwald is a Research Geologist working at the Geosciences and Environmental Change Science Center
Education
PhD, Earth Sciences, The Ohio State University, 2009
MS, Geosciences, University of Massachusetts Amherst, 2004
BA, Environmental Science/Geology, Colorado College, 1999
Appointments
2015 - present Research Geologist, Geosciences and Environmental Change Science Center, USGS, Denver, Colorado
2011 - 2015 Research Scientist, Department of Environmental Sciences, Informatics and Statistics, University of Venice, Italy
2009 - 2011 Marie Curie Post-Doctoral Fellow, Italian National Research Council (CNR-IPDA), Italy
2009 Visiting Assistant Professor, Geology Department, Colorado College
1999 - 2001 U.S. Peace Corps, Environmental Engineer, Bolivia
Science and Products
Rapa Nui (Easter Island) Rano Raraku crater lake basin: Geochemical characterization and implications for the Ahu-Moai Period
A multi-decadal geochemical record from Rano Aroi (Easter Island/Rapa Nui): Implications for the environment, climate and humans during the last two millennia
Trace and rare earth elements determination in milk whey from the Veneto region, Italy
Boreal blazes: Biomass burning and vegetation types archived in the Juneau Icefield
The Great Acceleration of fragrances and PAHs archived in an ice core from Elbrus, Caucasus
Dissolved organic matter in the deep TALDICE ice core: A nano-UPLC-nano-ESI-HRMS method
PaCTS 1.0: A crowdsourced reporting standard for paleoclimate data
Fire, vegetation, and Holocene climate in a southeastern Tibetan lake: a multi-biomarker reconstruction from Paru Co
Global Modern Charcoal Dataset (GMCD): A tool for exploring proxy-fire linkages and spatial patterns of biomass burning
Lake sediment fecal and biomass burning biomarkers provide direct evidence for prehistoric human-lit fires in New Zealand
High latitude Southern Hemisphere fire history during the mid-late Holocene (750- 6000 yr BP)
A North American Hydroclimate Synthesis (NAHS) of the Common Era
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Fire and vegetation changes recorded in Alaskan ice cores
Fire, human activity, and climate records in southwestern US sediments
Did we start the fire? Climate, Fire and Humans
Terrestrial Records of Holocene Climate Change: Fire, climate and humans
Investigating fire frequency and vegetative combustion sources using wildland fire tracer molecules archived in the Juneau Icefield of Alaska
Science and Products
- Publications
Filter Total Items: 16
Rapa Nui (Easter Island) Rano Raraku crater lake basin: Geochemical characterization and implications for the Ahu-Moai Period
Rano Raraku, the crater lake constrained by basaltic tuff that served as the primary quarry used to construct the moai statues on Rapa Nui (Easter Island), has experienced fluctuations in lake level over the past centuries. As one of the only freshwater sources on the island, understanding the present and past geochemical characteristics of the lake water is critical to understand if the lake coulA multi-decadal geochemical record from Rano Aroi (Easter Island/Rapa Nui): Implications for the environment, climate and humans during the last two millennia
The small and remote Easter Island (Rapa Nui) has a complex and still partially unknown history of human colonization and interactions with the environment. Previous research from sedimentary archives collected in the three freshwater bodies of Rapa Nui document dramatic environmental changes over the last two millennia. Yet, the characteristics of sediments and paleoenvironmental records are chalTrace and rare earth elements determination in milk whey from the Veneto region, Italy
Multi-element analyses determine the content of 17 trace elements (Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Cd, Cs, Ba, Pb, U) and 14 rare earth elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Lu, Y) in whey samples from cow and goat milk by inductively coupled plasma mass spectrometry and inductively coupled plasma-sector field mass spectrometry. A total of 261 milk whey samples wBoreal blazes: Biomass burning and vegetation types archived in the Juneau Icefield
The past decade includes some of the most extensive boreal forest fires in the historical record. Warming temperatures, changing precipitation patterns, the desiccation of thick organic soil layers, and increased ignition from lightning all contribute to a combustive combination. Smoke aerosols travel thousands of kilometers, before blanketing the surfaces on which they fall, such as the Juneau IcThe Great Acceleration of fragrances and PAHs archived in an ice core from Elbrus, Caucasus
The Great Acceleration of the anthropogenic impact on the Earth system is marked by the ubiquitous distribution of anthropogenic materials throughout the global environment, including technofossils, radionuclides and the exponential increases of methane and carbon dioxide concentrations. However, personal care products as direct tracers of human domestic habits are often overlooked. Here, we preseDissolved organic matter in the deep TALDICE ice core: A nano-UPLC-nano-ESI-HRMS method
Trace organic compounds in deep ice cores supply important paleoclimatic information. Untargeted analyses of dissolved organic matter provide an overview of molecular species in ice samples however, sample volumes usually required for these analyses are generally not available from deep ice cores. Here, we developed an analytical method using a nano-UPLC-nano-ESI-HRMS to detect major molecular spePaCTS 1.0: A crowdsourced reporting standard for paleoclimate data
The progress of science is tied to the standardization of measurements, instruments, and data. This is especially true in the Big Data age, where analyzing large data volumes critically hinges on that data being standardized. Accordingly, the lack of community-sanctioned data standards in paleoclimatology has largely precluded the benefits of Big Data advances in the field. Building upon recent efFire, vegetation, and Holocene climate in a southeastern Tibetan lake: a multi-biomarker reconstruction from Paru Co
The fire history of the Tibetan Plateau over centennial to millennial timescales is not well known. Recent ice core studies reconstruct fire history over the past few decades but do not extend through the Holocene. Lacustrine sedimentary cores, however, can provide continuous records of local environmental change on millennial scales during the Holocene through the accumulation and preservation ofGlobal Modern Charcoal Dataset (GMCD): A tool for exploring proxy-fire linkages and spatial patterns of biomass burning
Progresses in reconstructing Earth's history of biomass burning has motivated the development of a modern charcoal dataset covering the last decades through a community-based initiative called the Global Modern Charcoal Dataset (GMCD). As the frequency, intensity and spatial scale of fires are predicted to increase regionally and globally in conjunction with changing climate, anthropogenic activitLake sediment fecal and biomass burning biomarkers provide direct evidence for prehistoric human-lit fires in New Zealand
Deforestation associated with the initial settlement of New Zealand is a dramatic example of how humans can alter landscapes through fire. However, evidence linking early human presence and land-cover change is inferential in most continental sites. We employed a multi-proxy approach to reconstruct anthropogenic land use in New Zealand’s South Island over the last millennium using fecal and plantHigh latitude Southern Hemisphere fire history during the mid-late Holocene (750- 6000 yr BP)
We determined the specific biomass burning biomarker levoglucosan in an ice core from the TALos Dome Ice CorE drilling project (TALDICE) during the mid- to late Holocene (6000–750 BP). The levoglucosan record is characterized by a long-term increase with higher rates starting at ∼ 4000 BP and peaks between 2500 and 1500 BP. The anomalous increase in levoglucosan centered at ∼ 2000 BP is consisA North American Hydroclimate Synthesis (NAHS) of the Common Era
This study presents a synthesis of century-scale hydroclimate variations in North America for the Common Era (last 2000 years) using new age models of previously published multiple proxy-based paleoclimate data. This North American Hydroclimate Synthesis (NAHS) examines regional hydroclimate patterns and related environmental indicators, including vegetation, lake water elevation, stream flow andByWater Resources, Climate Research and Development Program, Energy Resources Program, Groundwater and Streamflow Information Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Florence Bascom Geoscience Center, Geology, Minerals, Energy, and Geophysics Science Center, Geosciences and Environmental Change Science Center, St. Petersburg Coastal and Marine Science CenterNon-USGS Publications**
Van Marle, M.J.E.; Kloster, Silvia; Magi, B.I.; Marlon, J.R.; Daniau, Anne-Laure; Field, R.D.; Arneth, Almut; Forrest, Matthew; Hantson, Stijn; Kehrwald, N.M.; Knorr, Wolfgang; Lasslop, Gitta; Li, Fang; Mangeon, Stéphane; Yue, Chao; Kaiser, J.W.; and van der Werf, G.R., 2017, Historic global biomass burning emissions for CMIP6 (BB4CMIP) based on merging satellite observations with proxies and fire models (1750-2015): Geoscientific Model Development, v. 10, iss. 9.Battistel, D., Argiriadis, E., Kehrwald, N., Spigariol, M., Russell, J.M., Barbante, C., 2017, Fire and human record at Lake Victoria, East Africa during the Early Iron Age: Did humans or climate cause massive ecosystem changes?: The Holocene, DOI: 10.1177/0959683616678466Gabrielli, P., Barbante, C., Bertagna, G., Merto, M., Binder, D., Carton, A., Carturan, L., Cazorzi, F., Cozzi, C., Dalla Dontana, G., Davis, M., De Blasi, F., Dinale, R., Draga, G., Dreossi, G., Festi, D., Frezzotti, M., Gabrieli, J., Galos, S.P., Ginot, P., Heidenwolf, P., Jenk, T.M., Kehrwald, N.M., Kenny, D., Magand, O., Mair, V., Mikhalenko, C., Lin, P.N., Oeggl, K., Piffer, G., Rinaldi, M., Schotterer, U., Schwikowski, M., Seppi, R., Spolaor, A., Stenni, B., Tonidandel, D., Uglietti, C., Zagorodnov, V., Zanoner, T., Sennaro, P., 2016, Age of the Mt. Ortles ice cores, the Tyrolean Iceman and glaciation of the highest summit of South Tyrol since the Northern Hemisphere Climatic Optimum: Cryosphere, 10, 6, 2779-2797, DOI:10.5194/tc-10-2779-2016Brovkin, V, Brücher, T., Kleinen, T., Zaehle, S., Joos, F., Roth, R., Spahni, R., Schmitt, J., Fischer, H., Leuenberger, M., Stone, E., Ridgewell, A., Chappellaz, J., Kehrwald, N., Barbante, C., Blunier, T., Dahl Jensen, D., 2016, Comparative carbon cycle dynamics of past and present interglacials: Quaternary Science Reviews, 137, 15-32, DOI/10.1016/j.quascirev.2016.01.028Zangrando, R., Barbaro, E., Vecchiato, M., Kehrwald, N., Barbante, C., Gambaro, A., 2016, Levoglucosan and phenols in marine, coastal and inland Antarctic aerosols: Science of the Total Environment, 544, 606-616, doi:10.1016/j.scitotenv.2015.11.166Zennaro, P., N. Kehrwald, J. Marlon, W. F. Ruddiman, T. Brücher, C. Agostinelli, D. Dahl-Jensen, R. Zangrando, A. Gambaro, and C. Barbante, 2015, Europe on fire three thousand years ago: Arson or climate?: Geophys. Res. Lett., 42, 5023–2033. doi: 10.1002/2015GL064259.Schüpbach, S., Kirchgeorg, T., Colombaroli, D., Beffa, G., Radaelli, M., Kehrwald, N., Barbante, C., 2015, Combining charcoal sediment and molecular markers to infer a Holocene fire history in the Maya lowlands of Petén, Guatemala: Quaternary Science Reviews 05/2015; 115. DOI:10.1016/j.quascirev.2015.03.004Portenga, E.W., Bierman, P.R., Duncan, C., Corbett, L.B., Kehrwald, N.M., Rood, D.H., 2015, Erosion rates of the Bhutanese Himalaya determined using in situ-produced 10Be: Geomorphology, 233, 122-126 doi:0.1016/j.geomorph.2014.09.027Kehrwald, N., Zennaro, P., Schüpbach, S., Kirchgeorg, T., McConnell, J.R., Zangrando, R., Gambaro, A., Barbante, C., 2015, Two thousand years of boreal biomass burning recorded in the NEEM ice cores: PAGES Magazine Vol. 23, 1, 14-15Wang, N., Xiaobo, W., Kehrwald, N., Li, Z., Li, Q., Jiang, X., Pu, J., 2015, Fukushima Nuclear Accident Recorded in Tibetan Plateau Snow Pits: PloS ONE, 10 (2) e0116580Gabrielli, P, Hardy, D.R., Kehrwald, N., Davis, M., Cozzi, G., Turetta, C., Barbante, C., Thompson, L.G., 2014, Deglaciated areas of Kilimanjaro as a source of volcanic trace elements deposited on the ice cap during the late Holocene: Quaternary Science Reviews, 93, 1-10, DOI:10.1016/j.quascirev.2014.03.007Guo, Z., Wang, N., Kehrwald, N.M., Mao, R., Wu, H., Wu, Y., Jiang, X., 2014, Temporal and spatial changes in Western Himalayan firn line altitudes from 1998 to 2009: Global and Planetary Change, 118, 97-105. DOI: 10.1016/j.gloplacha.2014.03.012Kirchgeorg, T., Schüpbach, S. Kehrwald, N., McWethy, D., Barbante, C., 2014, Method for determining levoglucosan, mannosan and galactosan in sediment to reconstruct past fire activity: Organic Geochemistry, 71, 1-6, DOI:10.1016/j.orggeochem.2014.02.014Zennaro, P., Kehrwald, N., McConnell, J., Schüpbach, S, Masselli, O., Marlon, J., Zangrando, R., Vallelonga, P., Spolaor, A., Varin, C., Borrotti, M., Gambaro, A., Barbante, B., 2014, Fire in ice: two millennia of Northern Hemisphere fire history from the Greenland NEEM ice core: Climate of the Past, 10, 1905–1924, 2014 www.clim-past.net/10/1905/2014/ doi:10.5194/cp-10-1905-2014
Kehrwald, N., Whitlock, C., Barbante, C., Brovkin, V., Daniau, A-L-. Kaplan, J.O., Marlon, J.R., Power, M.J., Thomicke, K., Van der Werf, G., 2013, Fire Research: Linking Past, Present and Future Data: EOS, Vol. 94, No. 46, 12 November 2013, DOI: 10.1002/2013EO460001Barbante, C., Kehrwald, N., Marianelli, P., Vinther, B. M.,Cozzi, G., Hammer, C., Clausen, H., Siggard Andersen, M., 2013, Greenland ice core evidence of the 79 AD Vesuvius eruption: Climate of the Past, 9, 1221–1232, 2013 www.clim-past.net/9/1221/2013/ doi:10.5194/cp-9-1221-2013Spolaor, A., Vallelonga, P., Plane, J.M.C, Kehrwald N., Gabrieli J., Varin C., Turetta C., Cozzi G., Boutron C. and Barbante C., 2013, Halogen species record Antarctic sea ice over glacial-interglacial periods: Atmospheric Chemistry and Physics, 13, 6623–6635, 2013 www.atmos-chem-phys.net/13/6623/2013/ doi:10.5194/acp-13-6623-2013
Spolaor A., Vallelonga P., Gabrieli J., Kehrwald N., Turetta C., Cozzi G., Poto L., Plane J.M.C., Boutron C.F., Barbante C., 2013, Speciation analysis of iodine and bromine at picogram-per-gram levels in polar ice: Analytical and Bioanalytical Chemistry, DOI: 10.1007/s00216-012-5806-0Zangrando, R., Barbaro, E., Zennaro, P., Rossi, S., Kehrwald, N.M., Gabrieli, J., Barbante, C., Gambaro, A., 2013, Biomass burning molecular markers in Arctic aerosols: Environmental Science and Technology, 47, 8565−8574, dx.doi.org/10.1021/es400125rKirchgeorg, T., Dreyer, A., Gabrieli, J., Kehrwald, N., Sigl, M., Schwikowski, M., Boutron, C., Gambaro, A., Barbante, C., Ebinghaus, R., 2013, Temporal Variations of Perfluoroalkyl Substances and Polybromintad Diphenyl Ethers in Alpine Snow: Environmental Pollution 178, 367-374.Spolaor, A., Vallelonga, P., Cozzi, G., Gabrieli, J., Varin, C., Kehrwald, N., Zennaro, P., Boutron, C., Barbante, C., 2013, Iron speciation influences iron bioavailability over glacial-interglacial cycles: Geophysical Research Letters, 40, 8, 618–1623, DOI: 10.1002/grl.50296Poto, L., Gabrieli, J., Crowhurst, S., Appleby, P.G., Ferretti, P., Zaccone, C., Surian, N., Ferretti, P., Cozzi, G., Turetta, C., Kehrwald, N.M., Barbante, C., 2013, The first continuous last Late Glacial - Holocene peat bog record from the Dolomites (NE Italian Alps): Quaternary International, http://dx.doi.org/10.1016/j.quaint.2013.05.001Kehrwald, N., P. Zennaro, Barbante, C., 2013, Biomass burning records over the present and past interglacial periods: PAGES News, 21, 1Kehrwald, N., Zangrando, R., Gabrielli, P., Barbante, C., Gambaro, A., 2012, Levoglucosan as a specific marker of fire events in Greenland snow: Tellus B, 64, May. 2012. Available at: http://www.tellusb.net/index.php/tellusb/article/view/18196Scalabrin, E., Zangrando, R., Barbaro, E., Kehrwald, N, Gabrieli, J., Barbante, C., Gambaro, A., 2012, Amino acids in Arctic aerosols: Atmospheric Chemistry and Physics 12, 10453-10463, doi:10.5194/acp-12-10453-2012
Gabrielli, P., Barbante, C., Carturan, L., Cozzi, G., Dalla Fontana, G., Dinale, R., Draga, G., Gabrieli, J., Kehrwald, N., Mair, V., Mikhalenko, G., Seppi, R., Spolaor, A., Thompson, L.G., Tonidandel, D., 2012, Discovery of cold ice in a deep drilling site in the Eastern European Alps: Geografia Fisica e Dinamica Quaternaria, 35, 101-105, Doi: 10.4461/GFDQ.2012.35.10
Gabrieli, J., Carturan, L., Gabrielli, P., Kehrwald, N., Turetta, C., Cozzi, G., Spolaor, A., Dinale, R., Staffler, H., Seppi, R., Dalla Fontana, G., Thompson, L.G., Barbante, C., 2011, Impact of Po Valley emissions on the highest glacier of the Eastern European Alps: Atmospheric Chemistry and Physcis, 11, 15, 80-87-8102, Doi:10.5194/acp-11-8087-2011
Kehrwald, N., McCoy, W., Thibeault, J., Burns, S., Oches, E., 2010, Paleoclimatic implications of modern and LGM European land-snail shell δ18O: Quaternary Research 74, 1, 167-177.Kehrwald, N., Zangrando, R., Gambaro, A., Barbante, C., 2010, Fire and climate: Biomass burning recorded in ice and lake cores: European Physical Journal, 9, 105-114, Doi: 10.1051/epjconf/201009008
Kehrwald, N., Zangrando, R., Gambaro, A., Cescon, P., Barbante, C., 2010, Specific molecular markers in ice cores provide large-scale patters in biomass burning: PAGES News, 18, 2Fortner, S., Fountain, A., Lyons, W., Welch, K., Kehrwald, N., 2009, Trace element and major ion concentrations and dynamics in glacier snow and melt: Eliot Glacier, Oregon Cascades: Hydrological Processes, 23, 2987-2996.
Kehrwald, N.M., Thompson, L.G., Yao, T., Mosley-Thompson, E., Schotterer, U., Alfimov, V., Beer, J., Eikenberg, J., Davis, M.E., 2008, Mass loss on Himalayan glacier endangers water resources: Geophysical Reserch Letters, 35, L22503, doi:10.1029/2008GL035556
Gardner, T., Marshall, J., Merritts, D., Bee, B., Burgette, R., Burton, E., Cooke, J.,Kehrwald, N., Protti, M., Fisher, D., Sak, P., 2001, Holocene forearc block rotation in response to seamount subduction, southeastern Peninsula, Costa Rica: Geology, 29, 2, 151-154.
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
- Science
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 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 galactosan, and...Fire, human activity, and climate records in southwestern US sediments
This research aims to determine if climate change or human activity was the primary driver of fire activity in southwestern Colorado.Did we start the fire? Climate, 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... - Data
Investigating fire frequency and vegetative combustion sources using wildland fire tracer molecules archived in the Juneau Icefield of Alaska
The past decade includes some of the most extensive boreal forest fires in the historical record. Environmental drivers include warming temperatures, changing precipitation patterns, desiccation of thick organic soil layers, and increased ignition frequency from lightning. Wildland fires produce smoke aerosols that can travel thousands of kilometers, before blanketing the surfaces on which they fa - News
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