The Arctic Small Tool Horizon: A Behavioral Model of the Dispersal of Human Population into an Unoccupied Niche

1976 ◽  
Vol 31 ◽  
pp. 156-163 ◽  
Author(s):  
Albert A. Dekin
Keyword(s):  
Sea Level ◽  
Human Population ◽  
Ecological Niche ◽  
Behavioral Model ◽  
The Arctic ◽  
Human Populations ◽  
Interior Alaska ◽  
Western Arctic ◽  
Rising Sea Level ◽  
Small Tool

There can be little doubt that the majority of the area through which the Arctic Small Tool horizon spread was unoccupied by human populations. This is particularly true of the Eastern Arctic, with the exception of the southern fringes where they may have come into contact with Archaic peoples near the ecotone between the tundra and the taiga. In the Western Arctic, it is apparent that there had been earlier human populations in many areas, but these later migrants appear to have occupied a previously unoccupied ecological niche. Geographically, they spread along the Arctic coasts until they had reached the maximum extent of seasonally frozen coasts, usually with adjacent tundra. While it may be that the rising sea level had flooded earlier evidence of such a coastal occupation arid that this habitat had not been unoccupied as it now appears, the present data support the inference that Arctic Small Tool populations were the first to accomplish a successful adaptation to these particular conditions in the American Arctic. For the present, I wish to focus on this coastal aspect of Arctic Small Tool peoples, ignoring (or not modeling) the expanded distribution of sites in interior Alaska which also occurred at this time.

scholarly journals Sub-permafrost methane seepage from open-system pingos in Svalbard

2020 ◽  
Vol 14 (11) ◽  
pp. 3829-3842 ◽  
Author(s):  
Andrew J. Hodson ◽  
Aga Nowak ◽  
Mikkel T. Hornum ◽  
Kim Senger ◽  
Kelly Redeker ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Sea Level ◽  
Open System ◽  
Current Knowledge ◽  
Complex Surface ◽  
Solubility Limit ◽  
The Arctic ◽  
Biogenic Methane ◽  
Methane Seepage ◽  
Rising Sea Level

Abstract. Methane release from beneath lowland permafrost represents an important uncertainty in the Arctic greenhouse gas budget. Our current knowledge is arguably best developed in settings where permafrost is being inundated by rising sea level, which means much of the methane is oxidised in the water column before it reaches the atmosphere. Here we provide a different process perspective that is appropriate for Arctic fjord valleys where local deglaciation causes isostatic uplift to out pace rising sea level. We describe how the uplift induces permafrost aggradation in former marine sediments, whose pressurisation results in methane escape directly to the atmosphere via groundwater springs. In Adventdalen, central Spitsbergen, we show how the springs are historic features responsible for the formation of open-system pingos and capable of discharging brackish waters enriched with high concentrations of mostly biogenic methane (average 18 mg L−1). Thermodynamic calculations show that the methane concentrations sometimes marginally exceed the solubility limit for methane in water at 0 ∘C (41 mg L−1). Year-round emissions from the pingos are described. During winter, rapid methane loss to the atmosphere occurs following outburst events from beneath an ice blister. During summer, highly variable emissions occur due to complex surface processes at the seepage point and its inundation by surface runoff. In spite of this complexity, our observations confirm that sub-permafrost methane migration deserves more attention for the improved forecasting of Arctic greenhouse gas emissions.

The Conservation and Biogeography of Amphibians in the Caribbean

2022 ◽  
Author(s):  
Harold Heatwole
Keyword(s):  
Climate Change ◽  
Sea Level ◽  
Human Population ◽  
Amphibian Conservation ◽  
Detailed Review ◽  
Island Group ◽  
The Status ◽  
The Face ◽  
The Caribbean ◽  
Rising Sea Level

An expansive and detailed review of the biology of Caribbean amphibians, considering their threats, conservation and outlook in a changing world. Amphibians are the group of vertebrates undergoing the fastest rate of extinction; it is urgent that we understand the causes of this and find means of protecting them. This landmark illustrated volume brings together the leading experts in the field. As well as offering an overview of the region as a whole, individual chapters are devoted to each island or island-group and the measures used to protect their amphibians through legislation or nature reserves. The biological background of insular biogeography, including its methods, analysis and results, is reviewed and applied specifically to the problems of Caribbean amphibians – this includes a re-examination of patterns and general ideas about the status of amphibians in the Anthropocene. The Conservation and Biogeography of Amphibians in the Caribbean offers an important baseline against which future amphibian conservation can be measured in the face of climate change, rising sea level and a burgeoning human population.

scholarly journals Open system pingos as hotspots for sub-permafrost methane emission in Svalbard

2020 ◽  
Author(s):  
Andrew Jonathan Hodson ◽  
Aga Nowak ◽  
Kim Senger ◽  
Kelly Redeker ◽  
Hanne H. Christiansen ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Sea Level ◽  
Open System ◽  
Current Knowledge ◽  
Methane Flux ◽  
Solubility Limit ◽  
The Arctic ◽  
Biogenic Methane ◽  
High Concentrations ◽  
Rising Sea Level

Abstract. Methane release from beneath lowland permafrost represents an important uncertainty in the Arctic greenhouse gas budget. Our current knowledge is arguably best-developed in settings where permafrost is being inundated by rising sea level, which means much of the methane is oxidised in the water column before it reaches the atmosphere. Here we provide a different process perspective that is appropriate for Arctic fjord valleys, where local deglaciation causes isostatic uplift to out-pace rising sea level. We show how the uplift induces permafrost aggradation in former marine sediments, whose pressurisation results in methane escape directly to the atmosphere via ground water springs. In Adventdalen, Central Spitsbergen, we show how the springs are historic features, responsible for the formation of open system pingos, and capable of discharging brackish waters enriched with high concentrations of mostly biogenic methane (average 18 mg L−1). Thermodynamic calculations show that the methane concentrations sometimes marginally exceed the solubility limit for methane in water at 0 °C (41 mg L−1). In our case study, emissions from just four pingo springs with a combined discharge of less than 2 L s−1 increase the land-atmosphere methane flux by 16 %. This confirms that sub-permafrost methane migration deserves more attention for improved forecasting of Arctic greenhouse gas emissions.

scholarly journals N2O dynamics in the western Arctic Ocean during the summer of 2017

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jang-Mu Heo ◽  
Seong-Su Kim ◽  
Sung-Ho Kang ◽  
Eun Jin Yang ◽  
Ki-Tae Park ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Environmental Changes ◽  
Chukchi Sea ◽  
Hot Spot ◽  
Open Water ◽  
Northern Region ◽  
The Arctic ◽  
Western Arctic Ocean ◽  
Deep Layers ◽  
Western Arctic

AbstractThe western Arctic Ocean (WAO) has experienced increased heat transport into the region, sea-ice reduction, and changes to the WAO nitrous oxide (N2O) cycles from greenhouse gases. We investigated WAO N2O dynamics through an intensive and precise N2O survey during the open-water season of summer 2017. The effects of physical processes (i.e., solubility and advection) were dominant in both the surface (0–50 m) and deep layers (200–2200 m) of the northern Chukchi Sea with an under-saturation of N2O. By contrast, both the surface layer (0–50 m) of the southern Chukchi Sea and the intermediate (50–200 m) layer of the northern Chukchi Sea were significantly influenced by biogeochemically derived N2O production (i.e., through nitrification), with N2O over-saturation. During summer 2017, the southern region acted as a source of atmospheric N2O (mean: + 2.3 ± 2.7 μmol N2O m−2 day−1), whereas the northern region acted as a sink (mean − 1.3 ± 1.5 μmol N2O m−2 day−1). If Arctic environmental changes continue to accelerate and consequently drive the productivity of the Arctic Ocean, the WAO may become a N2O “hot spot”, and therefore, a key region requiring continued observations to both understand N2O dynamics and possibly predict their future changes.

scholarly journals Arctic Ocean stratification set by sea level and freshwater inputs since the last ice age

2021 ◽  
Author(s):  
Jesse R. Farmer ◽  
Daniel M. Sigman ◽  
Julie Granger ◽  
Ona M. Underwood ◽  
François Fripiat ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Surface Waters ◽  
Ice Age ◽  
The Arctic ◽  
Bering Strait ◽  
Central Arctic Ocean ◽  
Phytoplankton Productivity ◽  
Nitrate Consumption ◽  
Western Arctic ◽  
Last Ice Age

AbstractSalinity-driven density stratification of the upper Arctic Ocean isolates sea-ice cover and cold, nutrient-poor surface waters from underlying warmer, nutrient-rich waters. Recently, stratification has strengthened in the western Arctic but has weakened in the eastern Arctic; it is unknown if these trends will continue. Here we present foraminifera-bound nitrogen isotopes from Arctic Ocean sediments since 35,000 years ago to reconstruct past changes in nutrient sources and the degree of nutrient consumption in surface waters, the latter reflecting stratification. During the last ice age and early deglaciation, the Arctic was dominated by Atlantic-sourced nitrate and incomplete nitrate consumption, indicating weaker stratification. Starting at 11,000 years ago in the western Arctic, there is a clear isotopic signal of Pacific-sourced nitrate and complete nitrate consumption associated with the flooding of the Bering Strait. These changes reveal that the strong stratification of the western Arctic relies on low-salinity inflow through the Bering Strait. In the central Arctic, nitrate consumption was complete during the early Holocene, then declined after 5,000 years ago as summer insolation decreased. This sequence suggests that precipitation and riverine freshwater fluxes control the stratification of the central Arctic Ocean. Based on these findings, ongoing warming will cause strong stratification to expand into the central Arctic, slowing the nutrient supply to surface waters and thus limiting future phytoplankton productivity.

scholarly journals Mental health issues from rising sea level in a remote coastal region of the Solomon Islands: current and future

2015 ◽  
Vol 23 (6_suppl) ◽  
pp. 22-25 ◽  
Author(s):  
James Asugeni ◽  
David MacLaren ◽  
Peter D Massey ◽  
Rick Speare
Keyword(s):  
Mental Health ◽  
Sea Level ◽  
Solomon Islands ◽  
Coastal Region ◽  
Health Issues ◽  
Mental Health Issues ◽  
Rising Sea Level

Global mapping of seasonal variations in tides from tide gauge and satellite altimeter data

2021 ◽  
Author(s):  
Inger Bij de Vaate ◽  
Henrique Guarneri ◽  
Cornelis Slobbe ◽  
Martin Verlaan
Keyword(s):  
Seasonal Variation ◽  
Sea Level ◽  
Seasonal Variations ◽  
Large Scale ◽  
Arctic Region ◽  
The Arctic ◽  
Altimeter Data ◽  
Tide Gauges ◽  
Tidal Constituents ◽  
The Arctic Region

<p>The existence of seasonal variations in major tides has been recognized since decades. Where Corkan (1934) was the first to describe the seasonal perturbation of the M2 tide, many others have studied seasonal variations in the main tidal constituents since. However, most of these studies are based on sea level observations from tide gauges and are often restricted to coastal and shelf regions. Hence, observed seasonal variations are typically dominated by local processes and the large-scale patterns cannot be clearly distinguished. Moreover, most tide models still perceive tides as annually constant and seasonal variation in tides is ignored in the correction process of satellite altimetry. This results in reduced accuracy of obtained sea level anomalies. </p><p>To gain more insight in the large-scale seasonal variations in tides, we supplemented the clustered and sparsely distributed sea level observations from tide gauges by the wealth of data from satellite altimeters. Although altimeter-derived water levels are being widely used to obtain tidal constants, only few of these implementations consider seasonal variation in tides. For that reason, we have set out to explore the opportunities provided by altimeter data for deriving seasonal modulation of the main tidal constituents. Different methods were implemented and compared for the principal tidal constituents and a range of geographical domains, using data from a selection of satellite altimeters. Specific attention was paid to the Arctic region where seasonal variation in tides was expected to be significant as a result of the seasonal sea ice cycle, yet data availability is particularly limited. Our study demonstrates the potential of satellite altimetry for the quantification of seasonal modulation of tides and suggests the seasonal modulation to be considerable. Already for M2 we observed changes in tidal amplitude of the order of decimeters for the Arctic region, and centimeters for lower latitude regions.</p><p> </p><div>Corkan, R. H. (1934). An annual perturbation in the range of tide. <em>Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character</em>, <em>144</em>(853), 537-559.</div>

scholarly journals Colonization of the Beaufort Coastal Plain by Beaver (Castor canadensis): A Response to Shrubification of the Tundra?

2017 ◽  
Vol 130 (4) ◽  
pp. 332 ◽  
Author(s):  
Thomas S Jung ◽  
Jay Frandsen ◽  
Danny C Gordon ◽  
David H Mossop
Keyword(s):  
Coastal Plain ◽  
Castor Canadensis ◽  
The Arctic ◽  
Beaver Dam ◽  
Winter Food ◽  
Western Arctic ◽  
Food Cache ◽  
Key Driver ◽  
River Valleys ◽  
American Beaver

A consequence of rapid global warming has been the shrubification (increase in shrub abundance, cover, and biomass) of arctic and alpine tundra ecosystems. Shrubification is likely a key driver of predicted and observed changes in the biodiversity of the Arctic. The American Beaver (Castor canadensis) has a vast distributional range, covering most of north America below the tree line; however, it has not been recorded in tundra habitat of the Beaufort Coastal Plain of Yukon and Alaska. in 2015, we observed a beaver dam, lodge, and winter food cache on the Babbage River in Ivvavik National Park, Yukon, Canada. Local Inuvialuit hunters first observed beavers on two rivers immediately east of the Babbage River in 2008 and 2009. Together, these are the first observations of beavers on the Beaufort Coastal Plain and indicate initial attempts at colonization. Colonization of the Beaufort Coastal Plain by beavers may have been facilitated by shrubification of river valleys on the tundra of northern Yukon and adjacent Alaska, which is a consequence of rapid climate warming in the western Arctic.

Wave refraction and reef island stability under rising sea level

2019 ◽  
Vol 172 ◽  
pp. 256-267 ◽  
Author(s):  
Mirella B. Costa ◽  
Eduardo C. Macedo ◽  
Eduardo Siegle
Keyword(s):  
Sea Level ◽  
Wave Refraction ◽  
Rising Sea Level
Sign in / Sign up

Export Citation Format

Share Document