Search USGS⌕ Search
Home/Archive/USGS

USGS · 70283320

Humans experienced abrupt environmental changes at White Sands during the Last Glacial Maximum

Kathleen B. Springer·Jeffrey S. Pigati·Jessica E. Tierney·Jeffrey S. Honke·Gonzalo Jiménez-Moreno·David Bustos·Thomas M. Urban·Daniel Odess·Edward A. Jolie·Alison J. Smith·Abigail J. Hunt·Patrick J. Martinez·Vincent L. Santucci·Sally C. Reynolds·Matthew R. Bennett
View original source ↗Export metadata ↓

Abstract

Expanded excavations at White Sands National Park have unearthed 20 stratigraphic horizons containing in situ human footprints, megafaunal trackways, and linear features created by travois. Advances in radiocarbon dating of conifer pollen, combined with ages of aquatic seeds, refines the chronology of the footprint-bearing sequence to between 23.5 and 21.7 thousand years ago (ka). Biomarker, pollen, and stratigraphic evidence indicate a complete overturning of the environment from a perennial lake to a playa and capture a large aridification episode coincident with Dansgaard-Oeschger event 2 at 23.2 ka, which shrank pluvial Lake Otero and allowed people to traverse the former shoreline area for nearly two millennia. This well-dated and highly resolved paleoclimate record provides compelling evidence that humans in North America experienced marked environmental changes during the Last Glacial Maximum.

Explore related subjects

Science AdvancesArticle
90° N90° S · 180° W ← longitude → 180° E
Source-reported bounding extent: 32.64122942693484° to 32.96895030956878° latitude; -106.50655935055961° to -106.12195995079219° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Kathleen B. Springer, Jeffrey S. Pigati, Jessica E. Tierney, Jeffrey S. Honke, Gonzalo Jiménez-Moreno, David Bustos, Thomas M. Urban, Daniel Odess, Edward A. Jolie, Alison J. Smith, Abigail J. Hunt, Patrick J. Martinez, Vincent L. Santucci, Sally C. Reynolds, Matthew R. Bennett. 2026-10-14. Humans experienced abrupt environmental changes at White Sands during the Last Glacial Maximum. https://doi.org/10.1126/sciadv.aeh0707

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS2026

Genomic structural variation rescues a classic biological invader from a population bottleneck

Invasion genetics presents a classic paradox: How do species successfully spread despite severe population bottlenecks? The brown treesnake ( Boiga irregularis ) in Guam represents a notable example of this phenomenon, having been introduced with only a handful of individuals. We show that the population endured an extreme bottleneck, with roughly half of the genome exhibiting runs of homozygosity, comparable to species of conservation concern. Despite this, we uncovered extensive diversity in the form of nearly 19,000 genomic structural variants, which affect almost eight times more of the genome than single-nucleotide variants and provide material for “rescuing” the population from inbreeding-driven declines. Structural variant density was highest in gene promoters, where recombination and DNA repair often occur, providing a mechanism for rapid evolution of gene-linked diversity. This diversity is enriched in genes vital for adaptive immunity and olfaction, suggesting genomic diversity in key chromosomal regions can rescue populations from inbreeding. This work has critical implications for invasion biology and conservation genetics practitioners.

Guam↗
USGS2026

Widespread abyssal turbidites record megathrust earthquake-triggered landslides and coseismic deformation in the Cascadia subduction zone

Abyssal marine turbidites provide some of the longest and most spatially extensive records of subduction zone earthquake recurrence globally; however, correlation of these deposits over long distances and interpretation of synchronous emplacement requires both an understanding of the turbidite generating systems and precise dating. Here, we present an integrated suite of high-resolution bathymetry, subbottom profiles, and sediment cores from combined autonomous underwater vehicle, remotely operated vehicle, and ship-based studies at a key paleoseismic site in the southern Cascadia subduction zone. We demonstrate how widespread, earthquake-triggered landslides on the lower slope deposit discrete, proximal mass transport deposits (MTDs) that grade offshore into complex, interfingered abyssal turbidites, which correspond to records of megathrust earthquake history. We propose accretion and oversteepening of thrust folds on the lower slope both preconditions the slope to fail and provides a perpetual source of unstable material to fail during every earthquake cycle. Furthermore, we suggest the periodic and pervasive landsliding indicates coseismic deformation of the outer accretionary wedge during megathrust rupture.

California, Oregon↗
USGS2026

Satellite observations reveal widespread alteration of river thermal regimes by U.S. dams

Dams are well known to alter river thermal regimes, but assessments of downstream temperature changes have been constrained to single dams, single basins, or specific seasonal windows, thus limiting knowledge of their widespread impacts. We used satellite-based thermal infrared observations to quantify river surface temperature differences up- and downstream of 287 large dams in the United States from 2013 to 2024 across all seasons. We found downstream river temperature differences for the majority (71%) of longitudinal river profiles. These downstream changes were typically warmer (60%), and, on average, were sustained or continued to increase within 20 km downstream of the dam. We also found that the magnitude and frequency of downstream alterations varied by dam type, with 91% of extreme (≥ ±4°C) differences occurring at dams with reservoirs. This work documents the pervasive effects of large dams on downstream ecosystems across all seasons on a national scale.

Science Advances↗