scholarly journals Remote Sensing of River Erosion on the Colville River, North Slope Alaska

2018 ◽  
Vol 10 (3) ◽  
pp. 397 ◽  
Author(s):  
◽  
◽  
Keyword(s):  
Remote Sensing ◽  
North Slope ◽  
River Erosion ◽  
Colville River

Palynology of Maastrichtian and Paleocene rocks, lower Colville River region, North Slope of Alaska

1988 ◽  
Vol 25 (4) ◽  
pp. 512-527 ◽  
Author(s):  
N. O. Frederiksen ◽  
T. A. Ager ◽  
L. E. Edwards
Keyword(s):  
Great Plains ◽  
Pollen Grains ◽  
North Slope ◽  
Northern Great Plains ◽  
Dinoflagellate Cysts ◽  
Spores And Pollen ◽  
The North ◽  
River Region ◽  
Colville River ◽  
North Slope Of Alaska

Outcrops of Maastrichtian rocks are rare on the North Slope of Alaska, and it is even more unusual to find outcrops of Maastrichtian and Paleocene age in the same vicinity. In general, Late Cretaceous and Paleogene rocks have not been well dated in published papers pertaining to northern Alaska. In this article, we describe palynomorph assemblages from 20 outcrop samples taken from nine localities along the lower Colville River and nearby areas. The latest Cretaceous palynomorph assemblages that are from marine rocks contain late Campanian or Maastrichtian dinoflagellate cysts; however, these cysts and other marine fossils are absent from the Tertiary samples, indicating that the Tertiary strata are nonmarine. Our latest Cretaceous and early Tertiary samples contain abundant spores and pollen grains and can be readily dated by reference to well-known pollen assemblages from the northern Great Plains and northwestern Canada. By dating each sampled outcrop, we can approximate the position of the Cretaceous–Tertiary boundary in the study area. Outcrop samples near the boundary are too widely separated stratigraphically to permit us to determine whether or not an unconformity exists at the boundary in the study area. Using spores, pollen grains, and dinoflagellate cysts, we date the samples below the Cretaceous–Tertiary boundary as being of approximately mid-Maastrichtian age and the samples above the boundary as being undifferentiated Paleocene in age. On the North Slope, as in regions to the east and south, the Maastrichtian pollen assemblages represent a different kind of flora and vegetation than the Paleocene assemblages. The Maastrichtian assemblages have moderately high diversities of angiosperm pollen taxa, most of which were probably insect pollinated. In contrast, the Paleocene assemblages have low diversities of angiosperm taxa, and many of these taxa were probably wind pollinated. Differences between the mid-Maastrichtian and Paleocene assemblages may have been caused at least in part by climatic changes but may also have been caused by the effects of a hypothesized bolide impact at the end of the Maastrichtian for which there is increasing evidence.

Mapping lake drainage and drained lake basins around Point Lay, Alaska using multi-source remote sensing data

2020 ◽  
Author(s):  
Helena Bergstedt ◽  
Benjamin Jones ◽  
Donald Walker ◽  
Louise Farquharson ◽  
Amy Breen ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Water Source ◽  
Water Sources ◽  
The Arctic ◽  
North Slope ◽  
The North ◽  
Temporal And Spatial ◽  
Lake Drainage ◽  
The Village ◽  
Lake Basins

<p>The North Slope of Alaska is a permafrost affected landscape dominated by lakes and drained lake basins of different sizes, depths and ages. Local communities across the North Slope region rely on lakes as a fresh water source and as locations for subsistence fishing, while industry relies on lakes as a source of water for winter transportation. Lake drainage events are often disruptive to both communities and industry that rely on being in close proximity to surface water sources in a region underlain by continuous permafrost. Drained lake basins of different ages can provide information on the past effects of climate change in the region. Studying past drainage events gives insight about the causes and mechanisms of these complex systems and benefits our understanding of lake evolution on the Arctic Coastal Plain in Alaska and the circumpolar Arctic as a whole.</p><p>Lakes and drained lake basins can be identified using high to medium resolution multispectral imagery from a range of satellite-based sensors. We explore the history of lake drainage in the region around Point Lay, a community located on the northern Chukchi Coast of Alaska, using a multi-source remote sensing approach. We study the evolution of lake basins before and after drainage events, their transformation from fishing grounds and water sources to grazing grounds and the geomorphological changes in the surrounding permafrost-dominated landscapes associated with these transitions.  </p><p>We build a dense and long time series of satellite imagery of past lake drainage events by including a multitude of remote sensing acquisitions from different sources into our analysis. Incorporating imagery from different sensors that have different temporal and spatial resolutions allows us to assess past drainage events and current geomorphological states of lakes and drained lake basins at different temporal and spatial scales. Point Lay is known to be an area where drainage events occur frequently and are of high relevance to the community. In August of 2016, the village drinking water source drained during a period of intense rainfall causing the village to seek alternative sources for a freshwater supply. Our results from the analysis of the remotely sensed imagery were shared directly with the community as part of a public seminar series in the Spring of 2020. We hope that results from our study near Point Lay, Alaska can contribute towards the selection of a new freshwater source lake for the village.</p>

scholarly journals Response of ice cover on shallow lakes of the North Slope of Alaska to contemporary climate conditions (1950–2011): radar remote-sensing and numerical modeling data analysis

2014 ◽  
Vol 8 (1) ◽  
pp. 167-180 ◽  
Author(s):  
C. M. Surdu ◽  
C. R. Duguay ◽  
L. C. Brown ◽  
D. Fernández Prieto
Keyword(s):  
Remote Sensing ◽  
Shallow Lakes ◽  
Ice Cover ◽  
North Slope ◽  
Lake Ice ◽  
Climate Conditions ◽  
The North ◽  
North Slope Of Alaska ◽  
Sar Data ◽  
Ice Model

Abstract. Air temperature and winter precipitation changes over the last five decades have impacted the timing, duration, and thickness of the ice cover on Arctic lakes as shown by recent studies. In the case of shallow tundra lakes, many of which are less than 3 m deep, warmer climate conditions could result in thinner ice covers and consequently, in a smaller fraction of lakes freezing to their bed in winter. However, these changes have not yet been comprehensively documented. The analysis of a 20 yr time series of European remote sensing satellite ERS-1/2 synthetic aperture radar (SAR) data and a numerical lake ice model were employed to determine the response of ice cover (thickness, freezing to the bed, and phenology) on shallow lakes of the North Slope of Alaska (NSA) to climate conditions over the last six decades. Given the large area covered by these lakes, changes in the regional climate and weather are related to regime shifts in the ice cover of the lakes. Analysis of available SAR data from 1991 to 2011, from a sub-region of the NSA near Barrow, shows a reduction in the fraction of lakes that freeze to the bed in late winter. This finding is in good agreement with the decrease in ice thickness simulated with the Canadian Lake Ice Model (CLIMo), a lower fraction of lakes frozen to the bed corresponding to a thinner ice cover. Observed changes of the ice cover show a trend toward increasing floating ice fractions from 1991 to 2011, with the greatest change occurring in April, when the grounded ice fraction declined by 22% (α = 0.01). Model results indicate a trend toward thinner ice covers by 18–22 cm (no-snow and 53% snow depth scenarios, α = 0.01) during the 1991–2011 period and by 21–38 cm (α = 0.001) from 1950 to 2011. The longer trend analysis (1950–2011) also shows a decrease in the ice cover duration by ~24 days consequent to later freeze-up dates by 5.9 days (α = 0.1) and earlier break-up dates by 17.7–18.6 days (α = 0.001).

scholarly journals Remote sensing application in monitoring change of river and coastlines of Morong, Bataan, Philippines

2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Annie Melinda Paz-Alberto 1 ◽  
Edmark P. Bulaong 1 ◽  
Jose T. Gavino 1 ◽  
Christopher R. Genaro 1 ◽  
Ranilo B. Lao 1
Keyword(s):  
Remote Sensing ◽  
Sea Level Rise ◽  
Sea Level ◽  
Field Measurements ◽  
Google Earth ◽  
Positional Accuracy ◽  
Annual Average ◽  
River Erosion ◽  
Sensing Application ◽  
Monitoring Change

Remote sensing offers fast, cheap and reliable method in detecting river and coastal changes. In this study, satellite imageries of Morong river and coastlines from 2006 to 2016 were collected and analyzed to monitor changes. Field measurements were also done using South Total Station (NTS-362R6L) in 2016 for comparison and validation of data. Results showed that the river outlet and the riverbank increased in width size due to erosion brought about by torrential rains and urban run-offs. Coastlines near the river narrowed in size or shifted landward due to coastal erosion and sea level rise. An interview was conducted to locals residing nearby the river and coast where strong typhoons were reported which cause geophysical changes in the area. The residents also observed sea level rise, coastal and river erosion which caused narrowing of the coastlines and widening of the river, respectively. Records of high tides and low tides collected were projected in annual average levels per month. The average level of low tides increased per year which can be a result of sea level rise. The computed RMSE between field and remote sensing measurements ranged from 0.1m to 0.67m which indicated positional accuracy of Google Earth in the area.

scholarly journals Stratigraphy and facies of Cretaceous Schrader Bluff and Prince Creek Formations in Colville River Bluffs, North Slope, Alaska

2007 ◽  
Author(s):  
Romeo M. Flores ◽  
Mark D. Myers ◽  
David W. Houseknecht ◽  
Gary D. Stricker ◽  
Donald W. Brizzolara ◽  
...  
Keyword(s):  
North Slope ◽  
Colville River

scholarly journals Remote Sensing-Based Statistical Approach for Defining Drained Lake Basins in a Continuous Permafrost Region, North Slope of Alaska

2021 ◽  
Vol 13 (13) ◽  
pp. 2539
Author(s):  
Helena Bergstedt ◽  
Benjamin M. Jones ◽  
Kenneth Hinkel ◽  
Louise Farquharson ◽  
Benjamin V. Gaglioti ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Statistical Approach ◽  
Wildlife Habitat ◽  
The Arctic ◽  
North Slope ◽  
Landsat 8 ◽  
The North ◽  
North Slope Of Alaska ◽  
Permafrost Regions ◽  
Lake Basins

Lake formation and drainage are pervasive phenomena in permafrost regions. Drained lake basins (DLBs) are often the most common landforms in lowland permafrost regions in the Arctic (50% to 75% of the landscape). However, detailed assessments of DLB distribution and abundance are limited. In this study, we present a novel and scalable remote sensing-based approach to identifying DLBs in lowland permafrost regions, using the North Slope of Alaska as a case study. We validated this first North Slope-wide DLB data product against several previously published sub-regional scale datasets and manually classified points. The study area covered >71,000 km2, including a >39,000 km2 area not previously covered in existing DLB datasets. Our approach used Landsat-8 multispectral imagery and ArcticDEM data to derive a pixel-by-pixel statistical assessment of likelihood of DLB occurrence in sub-regions with different permafrost and periglacial landscape conditions, as well as to quantify aerial coverage of DLBs on the North Slope of Alaska. The results were consistent with previously published regional DLB datasets (up to 87% agreement) and showed high agreement with manually classified random points (64.4–95.5% for DLB and 83.2–95.4% for non-DLB areas). Validation of the remote sensing-based statistical approach on the North Slope of Alaska indicated that it may be possible to extend this methodology to conduct a comprehensive assessment of DLBs in pan-Arctic lowland permafrost regions. Better resolution of the spatial distribution of DLBs in lowland permafrost regions is important for quantitative studies on landscape diversity, wildlife habitat, permafrost, hydrology, geotechnical conditions, and high-latitude carbon cycling.

Sign in / Sign up

Export Citation Format

Share Document