Search

Your search keyword '"Stroup, Justin S."' showing total 16 results
Start Over Author "Stroup, Justin S."
16 results on '"Stroup, Justin S."'

3. Biomarker and Pollen Evidence for Late Pleistocene Pluvials in the Mojave Desert

Author

Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Peaple, Mark D, Bhattacharya, Tripti, Lowenstein, Tim K, Olson, Kristian J, Stroup, Justin S, Tierney, Jessica E, Feakins, Sarah J, Mcgee, David, Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Peaple, Mark D, Bhattacharya, Tripti, Lowenstein, Tim K, Olson, Kristian J, Stroup, Justin S, Tierney, Jessica E, Feakins, Sarah J, and Mcgee, David

Published
2023

11. BATHYMETRIC MAPPING AND SONAR IMAGING OF TUFA AT GREEN LAKES: FAYETTEVILLE, NEW YORK.

Author

STROUP, JUSTIN S., LEE, RACHEL J., FRIEMAN, RICHARD A., BECKER, AIDAN R., and INSOLIA, NICOLE M.

Abstract

The Fayetteville Green Lakes State Park, located in Fayetteville, New York, consists of two deep (48 m+), meromictic (non-mixing) lakes with unique limnological, bacterial, and chemical characteristics. These lakes, named Round Lake and its larger companion Green Lake, have been extensively studied for nearly 200 years because of their unique character. The lake water contains two distinct layers, the oxygenrich mixolimnion and the anoxic monimolimnion divided by the chemocline (a chemical compositional boundary). Tufa deposits exist along the shorelines of both lakes at various depths and are a product of groundwater discharge into the lakes, as well as the lakes' unique water chemistry and microbial communities. Here, we use sonar imaging techniques to produce updated bathymetric maps of Green and Round Lake, and provide the first detailed characterization of the nearshore environment using sidescanning sonar imagery to determine the locations and morphologies of tufa deposits. We also document shoreline debris specifically large tree trunks and branches which have fallen into the lake over time and are frequently encrusted. We identified fourteen locations of tufa ranging from large formations (10s of meters long) to small tufa heads (~1 m) in Green Lake. Our updated bathymetry and documentation of tufa locations and geometry expand the extensive history of prior work, will aid future investigators by revealing lesser-known tufa localities, and will assist the Fayetteville Green Lakes State Park with monitoring and conservation efforts for this ecologically unique area. [ABSTRACT FROM AUTHOR]

Published
2022

12. Natural and anthropogenic variations in atmospheric mercury deposition during the Holocene near Quelccaya Ice Cap, Peru

Author

Beal, Samuel A., Kelly, Meredith A., Stroup, Justin S., Jackson, Brian P., Lowell, Thomas V., and Tapia, Pedro M.

Subjects
Background level, mercury record, Pre-industrial, Holocene, toxic metals, tropical climate, atmospheric deposition, purl.org/pe-repo/ocde/ford#1.05.09 [https], Mercury (metal), Cuzco [Peru], Natural sources, Lake sediments, Atmospheric mercury deposition, sediment core, Lakes, lake sediment, Quelccaya Ice Cap, Spatial extent, Peru, Reservoirs (water), Deposition, global climate, mercury (element), Tropical climates
Abstract

Mercury (Hg) is a toxic metal that is transported globally through the atmosphere. Emissions of Hg from mineral reservoirs and recycling between soil/biomass, oceans, and the atmosphere are fundamental to the global Hg cycle, yet past emissions from anthropogenic and natural sources are not fully constrained. We use a sediment core from Yanacocha, a headwater lake in southeastern Peru, to study the anthropogenic and natural controls on atmospheric Hg deposition during the Holocene. From 12.3 to 3.5 ka, Hg fluxes in the record are relatively constant (mean ± 1σ: 1.4 ± 0.6 μg m-2 a-1). Past Hg deposition does not correlate with changes in regional temperature and precipitation or with most large volcanic events that occurred regionally (~300-400 km from Yanacocha) and globally. In 1450 B.C. (3.4 ka), Hg fluxes abruptly increased and reached the Holocene-maximum flux (6.7 μg m-2 a-1) in 1200 B.C., concurrent with a ~100 year peak in Fe and chalcophile metals (As, Ag, Tl) and the presence of framboidal pyrite. Continuously elevated Hg fluxes from 1200 to 500 B.C. suggest a protracted mining-dust source near Yanacocha that is identical in timing to documented pre-Incan cinnabar mining in central Peru. During Incan and Colonial time (A.D. 1450-1650), Hg deposition remains elevated relative to background levels but lower relative to other Hg records from sediment cores in central Peru, indicating a limited spatial extent of preindustrial Hg emissions. Hg fluxes from A.D. 1980 to 2011 (4.0 ± 1.0 μg m-2 a-1) are 3.0 ± 1.5 times greater than preanthropogenic fluxes. Key Points Hg deposition did not vary with past precipitation, temperature, and volcanism Maximum Holocene Hg fluxes occurred ~3 thousand years ago Modern Hg fluxes are 3 times greater than natural fluxes.

Published
2014

Catalog

Books, media, physical & digital resources
See catalog results