DOI: 10.5061/dryad.tb2rbp0dd
title: Late Holocene tundra fires and linkages to climate and vegetation in northern Alaska

description: Charcoal particles in lake-sediments can reveal past fires and linkages to
 climate and vegetation change. We use analyses of charcoal accumulation
 rates from two lakes (Lake I4 and Kirk Lake) on the Alaskan North Slope to
 reconstruct past fire activity, and charcoal morphology to identify
 changes in fuel sources. This dataset contains 1) chronological data for
 both lake-sediment cores used to construct age-depth models (Pb-210 and
 radiocarbon), 2) magnetic susceptibility measurements for both cores, 3)
 macroscopic charcoal particle counts for both sites at three size
 fractions (90-125µm, 125-250µm, and &gt;250µm), and 4) charcoal
 morphology (classes defined in associated Arctic Science
 publication). 
description:  <sup>210</sup>Pb data was generated vis gamma
 spectrometry on a Mirion HPGe small anode germanium (SAGe) well detector.
 Activities for <sup>210</sup>Pb (46.5 keV) and
 <sup>226</sup>Ra (calculated from average of
 <sup>214</sup>Pb (351.9 keV) and <sup>214</sup>Bi
 (609.3 keV) activities) presented.  Radiocarbon ages
 were measured from macrofossil material extracted from cores and submitted
 to the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) for
 AMS <sup>14</sup>C dating. Reported <sup>14</sup>C
 ages were calibrated with the INTCAL 20 dataset  using CALIB version
 8.2.  Magnetic susceptibility was measured on split
 core surfaces (continuous measurements) on a Geotek MSCL-S system with a
 Barrington MS-C point meter.  Charcoal particles were
 sieved from measured volumes of wet sediment with a sieve cascade of 90,
 125, and 250 µm, and particles counts were enumerated for each size
 fraction.  Charcoal morphologies for all particles
 &gt;90 µm were identified (see publication for full methodology and
 references). Morphotypes M and P are irregular particles with and without
 structure, morphotypes S and C are geometric particles with and without
 structure, and morphotypes F and D are elongated particles with and
 without ramifications.
description: # Late Holocene Tundra Fires and Linkages to Climate and Vegetation in
 Northern Alaska Dataset DOI:
 [10.5061/dryad.tb2rbp0dd](10.5061/dryad.tb2rbp0dd) ## Description of the
 data and file structure Charcoal counts (three size fractions), charcoal
 morphology, and chronological control from two sites on the Alaskan North
 Slope, near Toolik Field Station. Sites are Lake I4 (Toolik LTER
 designation) and Kirk Lake (informal name). Data was collected to provide
 insight into fire history in the region over the past 7000 years. Please
 see publication for methodological details (Frank-Depue, L., and M.L.
 Chipman, 2025, *Arctic Science*). ## Files and Variables
 **Frank-Depue_and_Chipman_2025_DRYAD.xlsx**: Tabs within this excel file
 and descriptions listed below. ***Metadata***: this tab contains study and
 site information, a list of all variables and abbreviations, and missing
 value designations for all data tabs ***Chronology-Data-Lake-I4***:
 chronological data for Lake I4, core RTS7U2 ***Charcoal-Data-Lake-I4***:
 charcoal particle counts for Lake I4, core RTS7U2
 ***Charcoal-Morphology-Lake-I4***: charcoal morphology counts for Lake I4,
 core RTS7U2 ***Mag-Sus-Data-Lake-I4***: magnetic susceptibility
 measurements for Lake I4, core RTS7U2 ***Chronology-Data-Kirk-Lake***:
 chronological data for Kirk Lake, core RTS5U3
 ***Charcoal-Data-Kirk-Lake***: charcoal particle counts for Kirk Lake,
 core RTS5U3 ***Charcoal-Morphology-Kirk-Lake***: charcoal morphology
 counts Kirk Lake, core RTS5U3 ***Mag-Sus-Data-Kirk-Lake***: magnetic
 susceptibility measurements for Kirk Lake, core RTS5U3 ## Code/software
 Microsoft Excel or comparable spreadsheet program. ## Access information
 Other publicly accessible locations of the data: * NCEI/NOAA IMPD