38 research outputs found
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Play Doh Coring Sampler Teacher Guide
Sediment cores are one of the most valuable types of samples for researchers who would like to learn about past climate or ecological changes. Cores can be retrieved from lakes, marshes, swamps, fields, and the ocean. The layers often reveal striking changes in color (see photos) reflecting changing sediment composition (i.e. more clay deposition or more microfossil s). This easy activity illustrates the basic geologic principle that horizontal layers of sediment become older the deeper you go below the Earthâs surface (Law of Superposition). Each layer contains sediment, fossils and organic matter etc. that can inform us about past changes in the associated water mass, and these changes are commonly associated with changes in the environment. This is also a way to demonstrate how geologists extract cores from lake bottoms or other areas
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Glacier Goo Activity
We provided the students with background information about what a glacier is, where they are, how they move. Then split the students into four groups each tasked with a question to answer through experimentation
Group s 1 and 2: How does temperature change the way a glacier flows? (we provided frozen, and room temperature goo, and a microwave for heating the goo)
Groups 3 and 4: How does friction or obstacles change the way a glacier flows? (we provided different pvc tubesâtubes with nothing done to them, tubes with paintable sand applied to them, and tubes with rocks glued to them. We also provided tin foil, oil, and water
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Sea Ice Food WebsâHands on Sampler Teacher Guide
This activity is a variation on a food web game that Iâve seen played many times before, but it is adapted to reflect a sea ice food web and show the many organisms that are intimately connected to polar bears
Oceanographic and Climatic Change in the Bering Sea, Last Glacial Maximum to Holocene
Postâglacial sea level rise led to a direct connection between the Arctic and Pacific Oceans via the Bering Strait. Consequently, the Bering Sea experienced changes in connectivity, size, and sediment sources that were among the most drastic of any ocean basin in the past 30,000 years. However, the sedimentary response to the interplay between climate change and sea level rise in highâlatitude settings such as Beringia remains poorly resolved. To ascertain changes in sediment delivery, productivity, and regional oceanography from the Last Glacial Maximum (LGM) to the Holocene, we analyzed sedimentological, geochemical, and isotopic characteristics of three sediment cores from the Bering Sea. Interpretations of productivity, terrestrial input, nutrient utilization, and circulation are based on organic carbon isotopes (δ13Corg), total organic carbon (TOC), bulk nitrogen isotopes, total organic nitrogen, carbon/nitrogen ratios, elemental Xâray fluorescence data, grain size, and presence of laminated or dysoxic, green intervals. Principal component analysis of these data captures key climatic intervals. The LGM was characterized by low productivity across the region. In the Bering Sea, deglaciation began around 18â17 ka, with increasing terrestrial sediment and TOC input. Marine productivity increased during the BøllingâAllerød when laminated sediments revealed dysoxic bottom waters where denitrification was extreme. The Younger Dryas manifested increased terrestrial input and decreased productivity, in contrast with the PreâBoreal, when productivity markedly rebounded. The PreâBoreal and BøllingâAllerød were similarly productive, but changes in the source of TOC and a δ13Corg depletion suggest the influence of a gradually flooding Bering Shelf during the PreâBoreal and Holocene
Bering Sea Surface Water Conditions during Marine Isotope Stages 12 to 10 at Navarin Canyon (IODP Site U1345)
Records of past warm periods are essential for understanding interglacial climate system dynamics. Marine Isotope Stage 11 occurred from 425 to 394âŻka, when global ice volume was the lowest, sea level was the highest, and terrestrial temperatures were the warmest of the last 500âŻkyr. Because of its extreme character, this interval has been considered an analog for the next century of climate change. The Bering Sea is ideally situated to record how opening or closing of the PacificâArctic Ocean gateway (Bering Strait) impacted primary productivity, sea ice, and sediment transport in the past; however, little is known about this region prior to 125âŻka. IODP Expedition 323 to the Bering Sea offered the unparalleled opportunity to look in detail at time periods older than had been previously retrieved using gravity and piston cores. Here we present a multi-proxy record for Marine Isotope Stages 12 to 10 from Site U1345, located near the continental shelf-slope break. MIS 11 is bracketed by highly productive laminated intervals that may have been triggered by flooding of the Beringian shelf. Although sea ice is reduced during the early MIS 11 laminations, it remains present at the site throughout both glacials and MIS 11. High summer insolation is associated with higher productivity but colder sea surface temperatures, which implies that productivity was likely driven by increased upwelling. Multiple examples of PacificâAtlantic teleconnections are presented including laminations deposited at the end of MIS 11 in synchrony with millennial-scale expansions in sea ice in the Bering Sea and stadial events seen in the North Atlantic. When global eustatic sea level was at its peak, a series of anomalous conditions are seen at U1345. We examine whether this is evidence for a reversal of Bering Strait throughflow, an advance of Beringian tidewater glaciers, or a turbidite
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Brine Rejection Activity
As salt water freezes, the salt is pushed out of solution through channels in the ice. This process is called brine rejection or brine exclusion. These channels are often used as microhabitats by ice algae, zooplankton, and even tiny fish. You can easily demonstrate what these channels look like
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Atmospheric CO2 and Temperature. What is Normal?
âHow much of a change in CO2 concentration and other GHGs is natural? âWhat is the normal range of CO2 and temperature variability? How is normal defined in this context? âWhat is the relationship between CO2 and global temperatures
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Polar Remote Sensing
â˘Satellite sensors specialize in collecting data about specific wavelengths The Geostationary Operational Environment Satellites (GOES) operated by NASA, NOAA, and the U.S. Department of Commerce provide continuous monitoring of weather conditions. Orbiting the Earthâs equatorial plane at a speed exactly matching the planetâs rotation, satellites in the GOES network seem to hover over fixed spots. They monitor atmospheric conditions that lead to hurricanes, flash floods, tornadoes, and hail storms
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Polar Remote Sensing
â˘Satellite sensors specialize in collecting data about specific wavelengths The Geostationary Operational Environment Satellites (GOES) operated by NASA, NOAA, and the U.S. Department of Commerce provide continuous monitoring of weather conditions. Orbiting the Earthâs equatorial plane at a speed exactly matching the planetâs rotation, satellites in the GOES network seem to hover over fixed spots. They monitor atmospheric conditions that lead to hurricanes, flash floods, tornadoes, and hail storms
Oceanographic and Climatic Change in the Bering Sea, Last Glacial Maximum to Holocene
Postâglacial sea level rise led to a direct connection between the Arctic and Pacific Oceans via the Bering Strait. Consequently, the Bering Sea experienced changes in connectivity, size, and sediment sources that were among the most drastic of any ocean basin in the past 30,000 years. However, the sedimentary response to the interplay between climate change and sea level rise in highâlatitude settings such as Beringia remains poorly resolved. To ascertain changes in sediment delivery, productivity, and regional oceanography from the Last Glacial Maximum (LGM) to the Holocene, we analyzed sedimentological, geochemical, and isotopic characteristics of three sediment cores from the Bering Sea. Interpretations of productivity, terrestrial input, nutrient utilization, and circulation are based on organic carbon isotopes (δ13Corg), total organic carbon (TOC), bulk nitrogen isotopes, total organic nitrogen, carbon/nitrogen ratios, elemental Xâray fluorescence data, grain size, and presence of laminated or dysoxic, green intervals. Principal component analysis of these data captures key climatic intervals. The LGM was characterized by low productivity across the region. In the Bering Sea, deglaciation began around 18â17 ka, with increasing terrestrial sediment and TOC input. Marine productivity increased during the BøllingâAllerød when laminated sediments revealed dysoxic bottom waters where denitrification was extreme. The Younger Dryas manifested increased terrestrial input and decreased productivity, in contrast with the PreâBoreal, when productivity markedly rebounded. The PreâBoreal and BøllingâAllerød were similarly productive, but changes in the source of TOC and a δ13Corg depletion suggest the influence of a gradually flooding Bering Shelf during the PreâBoreal and Holocene.This article is published as Pelto, Ben M., Beth E. Caissie, Steven T. Petsch, and Julie BrighamâGrette. "Oceanographic and Climatic Change in the Bering Sea, Last Glacial Maximum to Holocene." Paleoceanography and Paleoclimatology 33, no. 1 (2018): 93-111. DOI: 10.1002/2017PA003265. Posted with permission.</p