76 FR 11139 - Fisheries of the Exclusive Economic Zone Off Alaska; Bering Sea and Aleutian Islands; Final 2011...

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2011-03-01

... information available for the assessment cycle in the fall of 2011. The Council is currently considering an...,660 213,000 -15,340 Rock sole BSAI 85,000 90,000 -5,000 85,000 90,000 -5,000 Greenland turbot BS 3,500...,000 197,660 176,510 21,150 Rock sole 5, 6 BSAI 248,000 224,000 85,000 75,905 9,095 243,000 219,000 85...

Whole genome sequencing of turbot (Scophthalmus maximus; Pleuronectiformes): a fish adapted to demersal life.

PubMed

Figueras, Antonio; Robledo, Diego; Corvelo, André; Hermida, Miguel; Pereiro, Patricia; Rubiolo, Juan A; Gómez-Garrido, Jèssica; Carreté, Laia; Bello, Xabier; Gut, Marta; Gut, Ivo Glynne; Marcet-Houben, Marina; Forn-Cuní, Gabriel; Galán, Beatriz; García, José Luis; Abal-Fabeiro, José Luis; Pardo, Belen G; Taboada, Xoana; Fernández, Carlos; Vlasova, Anna; Hermoso-Pulido, Antonio; Guigó, Roderic; Álvarez-Dios, José Antonio; Gómez-Tato, Antonio; Viñas, Ana; Maside, Xulio; Gabaldón, Toni; Novoa, Beatriz; Bouza, Carmen; Alioto, Tyler; Martínez, Paulino

2016-06-01

The turbot is a flatfish (Pleuronectiformes) with increasing commercial value, which has prompted active genomic research aimed at more efficient selection. Here we present the sequence and annotation of the turbot genome, which represents a milestone for both boosting breeding programmes and ascertaining the origin and diversification of flatfish. We compare the turbot genome with model fish genomes to investigate teleost chromosome evolution. We observe a conserved macrosyntenic pattern within Percomorpha and identify large syntenic blocks within the turbot genome related to the teleost genome duplication. We identify gene family expansions and positive selection of genes associated with vision and metabolism of membrane lipids, which suggests adaptation to demersal lifestyle and to cold temperatures, respectively. Our data indicate a quick evolution and diversification of flatfish to adapt to benthic life and provide clues for understanding their controversial origin. Moreover, we investigate the genomic architecture of growth, sex determination and disease resistance, key traits for understanding local adaptation and boosting turbot production, by mapping candidate genes and previously reported quantitative trait loci. The genomic architecture of these productive traits has allowed the identification of candidate genes and enriched pathways that may represent useful information for future marker-assisted selection in turbot. © The Author 2016. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

Chlorinated hydrocarbon contaminants and metabolites in polar bears (Ursus maritimus) from Alaska, Canada, East Greenland, and Svalbard: 1996-2002.

PubMed

Verreault, Jonathan; Muir, Derek C G; Norstrom, Ross J; Stirling, Ian; Fisk, Aaron T; Gabrielsen, Geir W; Derocher, Andrew E; Evans, Thomas J; Dietz, Rune; Sonne, Christian; Sandala, Gregory M; Gebbink, Wouter; Riget, Frank F; Born, Erik W; Taylor, Mitch K; Nagy, John; Letcher, Robert J

2005-12-01

A suite of chlorinated hydrocarbon contaminants (CHCs) including organochlorine pesticides (OCPs) and by-products, polychlorinated biphenyls (PCBs), and methyl sulfone (MeSO2) PCB and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) metabolites were determined in adipose tissue of 107 adult and sub-adult polar bears, almost exclusively females, sampled between 1996 and 2002 from populations spanning Arctic and Subarctic regions of Alaska, Canada, East Greenland, and Svalbard. The East Greenland and Svalbard populations of polar bears were distinguished by higher proportions of dichlorodiphenyldichloroethane (DDT)-related compounds, nonachlors, oxychlordane, and higher-chlorinated and persistent PCB congeners (hepta- to nona-chlorinated). Conversely, Alaska, the westernmost population of the North American Arctic, was characterized by higher proportions of relatively volatile compounds such as hexachlorocyclohexanes (HCHs) and pentachlorobenzene (PnCBz), lower-chlorinated PCB congeners (tri- to penta-chlorinated), and lower proportions of oxychlordane. Geometric mean (GM) with 95% confidence limits (CL) SigmaHCH concentrations were highest in Alaska male polar bear fat samples (GM 593; CL 363-909 ng g-1 lipid weight), SigmaDDT concentration were highest in East Greenland female samples (GM 309; CL 249-490 ng g-1 l.w.), and Sigma42PCB (GM 5972; CL 4637-9129 ng g-1 l.w.) and SigmaMeSO2-PCB (GM 198; CL 162-279 ng g-1 l.w.) concentrations were highest in female samples collected from Svalbard. The distribution of Sigma-chlordane-related compounds (SigmaCHL), SigmaCBz, mirex, and dieldrin was relatively uniform among the populations of polar bears investigated. The present 1996-2002 data of female polar bear fat samples was compared to spatial assessments of female polar bear fat samples collected between 1989 and 1993 from comparable populations. The two-point temporal comparisons showed a general decrease for age-adjusted mean concentrations of SigmaCHL, p

Taxonomic and functional metagenomic profiling of gastrointestinal tract microbiome of the farmed adult turbot (Scophthalmus maximus).

PubMed

Xing, Mengxin; Hou, Zhanhui; Yuan, Jianbo; Liu, Yuan; Qu, Yanmei; Liu, Bin

2013-12-01

Metagenomics combined with 16S rRNA gene sequence analyses was applied to unveil the taxonomic composition and functional diversity of the farmed adult turbot gastrointestinal (GI) microbiome. Proteobacteria and Firmicutes which existed in both GI content and mucus were dominated in the turbot GI microbiome. 16S rRNA gene sequence analyses also indicated that the turbot GI tract may harbor some bacteria which originated from associated seawater. Functional analyses indicated that the clustering-based subsystem and many metabolic subsystems were dominant in the turbot GI metagenome. Compared with other gut metagenomes, quorum sensing and biofilm formation was overabundant in the turbot GI metagenome. Genes associated with quorum sensing and biofilm formation were found in species within Vibrio, including Vibrio vulnificus, Vibrio cholerae and Vibrio parahaemolyticus. In farmed fish gut metagenomes, the stress response and protein folding subsystems were over-represented and several genes concerning antibiotic and heavy metal resistance were also detected. These data suggested that the turbot GI microbiome may be affected by human factors in aquaculture. Additionally, iron acquisition and the metabolism subsystem were more abundant in the turbot GI metagenome when compared with freshwater fish gut metagenome, suggesting that unique metabolic potential may be observed in marine animal GI microbiomes. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Expressed sequence tags (ESTs) from immune tissues of turbot (Scophthalmus maximus) challenged with pathogens

PubMed Central

Pardo, Belén G; Fernández, Carlos; Millán, Adrián; Bouza, Carmen; Vázquez-López, Araceli; Vera, Manuel; Alvarez-Dios, José A; Calaza, Manuel; Gómez-Tato, Antonio; Vázquez, María; Cabaleiro, Santiago; Magariños, Beatriz; Lemos, Manuel L; Leiro, José M; Martínez, Paulino

2008-01-01

Background The turbot (Scophthalmus maximus; Scophthalmidae; Pleuronectiformes) is a flatfish species of great relevance for marine aquaculture in Europe. In contrast to other cultured flatfish, very few genomic resources are available in this species. Aeromonas salmonicida and Philasterides dicentrarchi are two pathogens that affect turbot culture causing serious economic losses to the turbot industry. Little is known about the molecular mechanisms for disease resistance and host-pathogen interactions in this species. In this work, thousands of ESTs for functional genomic studies and potential markers linked to ESTs for mapping (microsatellites and single nucleotide polymorphisms (SNPs)) are provided. This information enabled us to obtain a preliminary view of regulated genes in response to these pathogens and it constitutes the basis for subsequent and more accurate microarray analysis. Results A total of 12584 cDNAs partially sequenced from three different cDNA libraries of turbot (Scophthalmus maximus) infected with Aeromonas salmonicida, Philasterides dicentrarchi and from healthy fish were analyzed. Three immune-relevant tissues (liver, spleen and head kidney) were sampled at several time points in the infection process for library construction. The sequences were processed into 9256 high-quality sequences, which constituted the source for the turbot EST database. Clustering and assembly of these sequences, revealed 3482 different putative transcripts, 1073 contigs and 2409 singletons. BLAST searches with public databases detected significant similarity (e-value ≤ 1e-5) in 1766 (50.7%) sequences and 816 of them (23.4%) could be functionally annotated. Two hundred three of these genes (24.9%), encoding for defence/immune-related proteins, were mostly identified for the first time in turbot. Some ESTs showed significant differences in the number of transcripts when comparing the three libraries, suggesting regulation in response to these pathogens. A total of

Roles of insulin-like growth factors in metamorphic development of turbot (Scophthalmus maximus).

PubMed

Jia, Yudong

2018-01-31

Larval turbot (Scophthalmus maximus) undergo metamorphosis, a late post-embryonic developmental event that precedes juvenile transition. Insulin-like growth factors (IGFs) are important endocrine/autocrine/paracrine factors that provide essential signals to control of the embryonic and postnatal development of vertebrate species, including fish. Accumulating evidence suggests that IGFs are involved in regulating the metamorphic development of flatfish. This mini review focus on the functions of all known IGFs (IGF-I and IGF-II) during the metamorphic development of turbot. Information about IGFs and insulin-like growth factors binding proteins (IGFBPs) from other teleosts is also included in this review to provide an overview of IGFs functions in the metamorphic development of turbot. These findings may enhance our understanding of the potential roles of the IGFs system in controlling of flatfish metamorphosis and contributing to the improvement of broodstock management strategies for larval turbot. Copyright © 2018 Elsevier Inc. All rights reserved.

Differentiation of farmed and wild turbot (Psetta maxima): proximate chemical composition, fatty acid profile, trace minerals and antimicrobial resistance of contaminant bacteria.

PubMed

Martínez, B; Miranda, J M; Nebot, C; Rodriguez, J L; Cepeda, A; Franco, C M

2010-10-01

The proximate, cholesterol, fatty acid and trace mineral compositions in the flesh of farmed and wild turbot (Psetta maxima) were evaluated. Additionally, the potential influence of the use of antimicrobial agents in the bacteria carried by farmed turbot was investigated. For this purpose, a total of 144 Pseudomonas spp. and 127 Aeromonas spp. were isolated and tested for their susceptibility to 12 antimicrobials by a disk diffusion method. Farmed turbot contained higher fat, cholesterol and calories as well as lower moisture content than its wild counterpart. The fatty acid profile of farmed turbot included higher levels of myristic, pentadecanoic, palmitoleic, gadoleic, cetoleic, linoleic, linolenic, stearidonic, eicosadienoic and eicosapentaenoic acids, and lower levels of stearic, arachidonic, docosapentaenoic and docosahexaenoic acids than its wild counterpart. The proportions of polyunsaturated fatty acids and n-3/n-6 ratios were higher in wild turbot than in farmed turbot. With respect to trace minerals, no toxic levels were found, and higher amounts of Cd, Co, Cu, Fe, Mn, Pb and Zn, as well as lower amounts of Cr, were found in farmed turbot relative to wild turbot. The antimicrobial resistance of Pseudomonas spp. and Aeromonas spp. were quite similar, with only the trimethoprim-sulfamethoxazole resistance of Aeromonas spp. isolated from farmed turbot being higher than those isolated from wild turbot. In the case of ampicillin, Pseudomonas spp. isolated from wild turbot showed higher resistance levels than those of their counterparts isolated from farmed turbot. In conclusion, the nutritional parameters of wild turbot are more adequate with respect to nutritional recommendations, while no differences were observed in food safety derived from trace mineral concentrations or the antimicrobial resistance of bacteria isolated from wild and farmed turbot.

Entering uncharted waters: Long-term dynamics of two data limited fish species, turbot and brill, in the North Sea

NASA Astrophysics Data System (ADS)

Kerby, Tina K.; Cheung, William W. L.; van Oosterhout, Cock; Engelhard, Georg H.

2013-11-01

In the North Sea, turbot (Scophthalmus maximus) and brill (Scophthalmus rhombus) represent highly valuable species in commercial fisheries. Still, available data for both species are limited, making stock assessment difficult. Long-term fisheries data have the potential to improve the understanding of stock dynamics such as long-term distribution changes or development in species' abundances. Historical British otter trawler lpue (landings-per-unit-effort) data from 1923 to 2009, and at the spatial scale of ICES rectangles, revealed that the distribution patterns of turbot and brill were different for most of the 20th century and only became similar in the recent decade. Further, between the 1920s and 1960s, turbot was commonly caught in the northern North Sea and in particular on Turbot Bank, at that time a turbot hotspot off the east coast of Scotland. Within a short time period turbot nearly disappeared from this region. Brill, in contrast, revealed a stable distribution in the southern and central North Sea with a slow expansion into the central North Sea. We used survey cpue (catch-per-unit-effort) from the International Bottom Trawl Survey (IBTS; 1970-2009) and the Beam Trawl Survey (BTS; 1985-2009), as well as British otter trawler lpue, as proxies for the abundance of adult turbot and brill. Commercial lpue suggested for brill and turbot a long-term decrease in abundance. IBTS cpue suggested an increase in abundance for turbot, but this was not confirmed by the BTS. For brill, both surveys did not show a clear trend.

Population ecology of turbot and brill: What can we learn from two rare flatfish species?

NASA Astrophysics Data System (ADS)

van der Hammen, Tessa; Poos, Jan Jaap; van Overzee, Harriët M. J.; Heessen, Henk J. L.; Magnusson, Arni; Rijnsdorp, Adriaan D.

2013-11-01

Turbot and brill are widely distributed in the Northeast Atlantic but occur at low abundance. They are ecologically very similar and closely related. The low abundance and the similarities make them particularly interesting to study the population dynamics because it raises the questions how the populations can sustain themselves at low abundances and how turbot and brill avoid strong interspecific competition. Knowledge of both species is hampered by lack of analysed data. The main objective of this study is therefore to increase the knowledge of turbot and brill and in particular to compare the two species in order to address the above questions. Based on biological samples collected in the North Sea, we calculated seasonal von Bertalanffy growth parameters, maturity ogives, monthly gonado-somatic indices (GSI) and condition factors (Fulton's K) and indices of inter- and intraspecific mean crowding and compared the results for turbot and brill. The main differences between the two species were found in their spawning period, with brill having a more protracted spawning period. Brill also showed an earlier peak in their GSI values, suggesting an earlier start of their spawning period. The mean crowding showed that interspecific competition was lower than intraspecific competition. The exploitation pattern was also studied. Turbot and brill are exploited as a bycatch species in the mixed demersal fishery. We found that productivity is highest in areas where the maximum temperature is close to the optimal temperature for growth (16-18 °C) and landings decrease where salinity falls below ~ 5 psu (turbot) and ~ 15 psu (brill). Recent fishing mortality rates of North Sea turbot are around 0.5-0.7, but there is no indication that recruitment is impaired at low levels of spawning stock biomass. We conclude that although both species have similar ecological characteristics, differences may reduce inter-specific competition.

Molecular cloning, subcelluar location and expression profile of signal transducer and activator of transcription 2 (STAT2) from turbot, Scophthalmus maximus.

PubMed

Wang, Na; Wang, Xian-Li; Yang, Chang-Geng; Chen, Song-Lin

2013-10-01

Signal transducer and activator of transcription 2 (STAT2) is an important molecule involved in the type I interferon signalling pathway. To date, little STAT2 homologue is available in fish except Atlantic salmon and goldfish. In this paper, STAT2 was firstly cloned and characterized from turbot, a marine flatfish with high economic value. Briefly, turbot STAT2 cDNA is 3206 bp in length encoding a predicted protein of 793 amino acids. The phylogenetic tree shows that turbot STAT2 protein shared the closest relationship with Atlantic salmon. Analysis of subcellular distribution indicates that STAT2 is mainly present in the cytoplasm of TK cells. Stat2 mRNA is constitutively expressed in widespread tissues and induced by several folds in turbot tissues and TK cells after stimulation with Vibrio anguillarum and lymphocystis disease virus (LCDV). Unlike the higher vertebrate STAT2, turbot STAT2 nuclear export signal (NES) exists not in the C-terminal 79 amino acids but in N-terminal 137-312 amino acids (STAT_alpha domain). The nuclear translocation of turbot STAT2 after Poly(I:C) treatment proved its transcription activity in TK cells. All these results suggested that STAT2 may be involved in the immune response in turbot as a transcription factor. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of waterborne Fe(II) on juvenile turbot Scophthalmus maximus: analysis of respiratory rate, hematology and gill histology

NASA Astrophysics Data System (ADS)

Wu, Zhihao; You, Feng; Liu, Hongjun; Liu, Mengxia; Li, Jun; Zhang, Peijun

2012-03-01

The concentration of Fe(II) is high in some groundwater supplies used in turbot culture, and the toxicity of waterborne Fe(II) is unknown. We investigated the stress responses of juvenile turbot, Scophthalmus maximus, exposed to Fe(II) of different concentrations (0.01, 0.05, 0.1, 0.5, 1, and 2 mg/L) for 1, 7, 14, and 28 d, under the same ambient conditions of other parameters. Changes in respiratory rate, hematological parameters, and gill structure were determined. The results show that waterborne Fe(II) did not cause severe hematological perturbation to turbot. A low-medium Fe(II) concentration (lower than 0.1 mg/L) could boost the respiratory rate, and caused no or very limited damage to fish. A high Fe(II) concentration (0.1 mg/L or higher), however, caused gill damage, such as vacuoles in branchial lamellae, epithelial necrosis, and hypertrophy of epithelial cells, and even death after extended exposure time. Therefore, excess waterborne Fe(II) and long-term exposure to Fe(II) could be responsible for poor growth and high mortality of turbot in culture. The concentration of waterborne Fe(II) in turbot culture should be kept below 0.1 mg/L.

Trophic transfer and effects of DDT in male hornyhead turbot (Pleuronichthys verticalis) from Palos Verdes Superfund site, CA (USA) and comparisons to field monitoring.

PubMed

Crago, Jordan; Xu, Elvis Genbo; Kupsco, Allison; Jia, Fang; Mehinto, Alvine C; Lao, Wenjian; Maruya, Keith A; Gan, Jay; Schlenk, Daniel

2016-06-01

High concentrations of DDT and metabolites (ΣDDT) have been detected in sediment and the demersal flatfish hornyhead turbot (Pleuronichtys verticalis) collected from Palos Verdes (PV), California, USA, a site contaminated with over 100 metric tons of DDT throughout 1960s-70s. This study was conducted to assess the transfer of ΣDDT from PV-sediment into polychaetes (Neanthes arenaceodentata) and hornyhead turbot, and to investigate if the responses in turbots from two different laboratory exposures mimic those in turbots caught in PV (PV-turbot). Turbot fed PV-sediment-contaminated polychaete for 7 days had liver concentrations of ΣDDT similar to PV-turbot. After 28 days, ΣDDT also accumulated in livers of turbot gavaged with a ΣDDT mixture. In vitro cell bioassays indicated significant increases of 17β-estradiol equivalents (EEQ) in turbot bile extracts as compared to the control in the 7-day study. These responses corresponded to those measured in PV-fish. Glucocorticoid receptor (GR), anti-androgen receptor (anti-AR), estrogen receptor (ER) or aryl hydrocarbon receptor (AhR) activities were also observed in extracts of PV-sediment, and PV-sediment-exposed worm. Anti-AR, AhR and GR activities were significantly higher in PV-sediment than reference sediment (San Diego, SD). Higher transcripts of hepatic VTG, ERα and ERβ were found in PV-turbot than SD-turbot, but were unaltered in fish exposed to sediment-contaminated worms for the 7-day study. In contrast, liver extracts from the 28-day treatment of ΣDDT showed lower EEQ but similar hepatic VTG and ERβ transcripts relative to those of PV-turbot. These data indicated that trophic transfer of sediment-associated DDT in 7-day exposures corresponded to field measurements of DDT residues and in vitro ER bioactivities, but failed to mimic in vivo biological effects observed in field fish. In contrast, treatment with ΣDDT alone for 28 days mimicked in vivo biological effects of DDTs in PV fish, but did not

Spatial and temporal trends of selected trace elements in liver tissue from polar bears (Ursus maritimus) from Alaska, Canada and Greenland.

PubMed

Routti, Heli; Letcher, Robert J; Born, Erik W; Branigan, Marsha; Dietz, Rune; Evans, Thomas J; Fisk, Aaron T; Peacock, Elizabeth; Sonne, Christian

2011-08-01

Spatial trends and comparative changes in time of selected trace elements were studied in liver tissue from polar bears from ten different subpopulation locations in Alaska, Canadian Arctic and East Greenland. For nine of the trace elements (As, Cd, Cu, Hg, Mn, Pb, Rb, Se and Zn) spatial trends were investigated in 136 specimens sampled during 2005-2008 from bears from these ten subpopulations. Concentrations of Hg, Se and As were highest in the (northern and southern) Beaufort Sea area and lowest in (western and southern) Hudson Bay area and Chukchi/Bering Sea. In contrast, concentrations of Cd showed an increasing trend from east to west. Minor or no spatial trends were observed for Cu, Mn, Rb and Zn. Spatial trends were in agreement with previous studies, possibly explained by natural phenomena. To assess temporal changes of Cd, Hg, Se and Zn concentrations during the last decades, we compared our results to previously published data. These time comparisons suggested recent Hg increase in East Greenland polar bears. This may be related to Hg emissions and/or climate-induced changes in Hg cycles or changes in the polar bear food web related to global warming. Also, Hg:Se molar ratio has increased in East Greenland polar bears, which suggests there may be an increased risk for Hg(2+)-mediated toxicity. Since the underlying reasons for spatial trends or changes in time of trace elements in the Arctic are still largely unknown, future studies should focus on the role of changing climate and trace metal emissions on geographical and temporal trends of trace elements.

Dietary protein requirement of juvenile turbot ( Scophthalmus maximus Linnaeus)

NASA Astrophysics Data System (ADS)

Liu, Xingwang; Mai, Kangsen; Liufu, Zhiguo; Ai, Qinghui

2015-04-01

The dietary protein requirement of juvenile turbot (initial average weight, 38.2 g ± 0.1 g) reared indoor in aerated aquaria was determined in this study. Five energy equal experimental diets were formulated with fish meal as protein source, which contained different concentrations of protein (47.2%, 51.0%, 54.6%, 59.3% and 63.6% of dry diet). Three groups of fish with 18 individuals in each, were cultured in 300-L tanks and fed twice a day for 8 weeks. During culture, temperature was controlled between 15.0 and 18.0°C, salinity was controlled between 28.5 and 32.0, acidity was controlled between pH7.8 and pH8.5, and ammonia nitrogen was maintained below 0.03 mg L-1 and dissolved oxygen was maintained about 7 mg L-1. Results showed that the growth of fish was significantly affected by dietary protein content ( P < 0.05). Specific growth rate ( SGR) of turbot increased when dietary protein content varied between 47.2% and 51.0% ( P < 0.05), and then kept stable when dietary protein content was higher than 51.0%. Fish which were fed the diet containing 63.6% protein showed the highest SGR while those fed the diet containing 59.3% protein showed the highest feed efficiency rate. No significant difference of feed intake and protein efficiency ratio was found among experimental diets ( P > 0.05). Broken-line regression analysis of SGR showed that the optimal dietary protein requirement of turbot was about 57.0%.

Enhancing the culturability of bacteria from the gastrointestinal tract of farmed adult turbot Scophthalmus maximus

NASA Astrophysics Data System (ADS)

Xing, Mengxin; Hou, Zhanhui; Qu, Yanmei; Liu, Bin

2014-03-01

Eighteen agar media were tested for the culture of gut-associated bacteria from farmed adult turbot ( Scophthalmus maximus), including 16 agar media with or without 1% gastrointestinal (GI) supernatant, or with 2% or 4% GI supernatant. A total of 1 711 colonies were analyzed and 24 operational taxonomic units (OTUs) were identified. The greatest bacterial diversity was isolated on Zobell 2216E/Zobell 2216E+ agar media, whereas MRS/MRS+ agar media produced a low diversity of colonies. Agar media with GI supernatant (1%, 2%, or 4%) showed increased diversity and yielded different profiles of OTUs from the corresponding original media, suggesting that GI supernatant provides substances that enhance the culture efficiency of bacteria from the turbot GI tract. The large majority of the colonies (82%) were γ-Proteobacteria, whereas 15.6% and 2.4% of colonies were Firmicutes and Actinobacteria, respectively. At the genus level, 49.4% of all colonies were assigned to Vibrio. Other potential pathogens, including Pseudomonas, Photobacterium, and Enterobacter, and potential probiotics, including Bacillus, Paenibacillus, and Pseudomonas, were also isolated on agar media. Most cultured bacteria belonged to species that were first described in the turbot GI tract. The impact of these species on turbot physiology and health should be investigated further.

Molecular cloning and multifunctional characterization of GRIM-19 (gene associated with retinoid-interferon-induced mortality 19) homologue from turbot (Scophthalmus maximus).

PubMed

Wang, Na; Wang, Xianli; Yang, Changgeng; Zhao, Xiaojie; Zhang, Yuxi; Wang, Tianzi; Chen, Songlin

2014-03-01

GRIM-19 (gene associated with retinoid-interferon-induced mortality 19), a novel cell death regulatory gene, plays important roles in cell apoptosis, embryogenesis, mitochondrial respiratory chain and immune response. To date, little information is known about fish GRIM-19 characteristics except orange-spotted grouper (Epinephelus coioides). Here a new GRIM-19 gene is identified and characterized from turbot (Scophthalmus maximus), an economic marine fish in China and Europe. Briefly, turbot GRIM-19 is a 595-bp gene encoding a 144 amino acids protein, which shares the closest relationship with Atlantic halibut (Hippoglossus hippoglossus). The expression of turbot grim-19 in liver, spleen and kidney is up-regulated by the infection of Vibrio anguillarum and LCDV (lymphocystis disease virus). Subsequently, a recombinant protein of turbot GRIM-19 is acquired and the anti-bacterial function is proved by liquid culture inhibition experiment. The subcellular location indicates that turbot GRIM-19 is co-localized with STAT3 in the cytoplasm, which is mainly determined by GRIM-19 41-84 amino acids and STAT3 1-321 amino acids. Finally, the involvements of turbot GRIM-19 in cell apoptosis and NF-κB pathway are investigated. All these data help to understand GRIM-19 function in fish, as well as provide the application possibility of GRIM-19 in fish disease resistance breeding. Copyright © 2013 Elsevier Ltd. All rights reserved.

Spatial and temporal trends of selected trace elements in liver tissue from polar bears (Ursus maritimus) from Alaska, Canada and Greenland

USGS Publications Warehouse

Routti, H.; Letcher, R.J.; Born, E.W.; Branigan, M.; Dietz, R.; Evans, T.J.; Fisk, A.T.; Peacock, E.; Sonne, C.

2011-01-01

Spatial trends and comparative changes in time of selected trace elements were studied in liver tissue from polar bears from ten different subpopulation locations in Alaska, Canadian Arctic and East Greenland. For nine of the trace elements (As, Cd, Cu, Hg, Mn, Pb, Rb, Se and Zn) spatial trends were investigated in 136 specimens sampled during 2005-2008 from bears from these ten subpopulations. Concentrations of Hg, Se and As were highest in the (northern and southern) Beaufort Sea area and lowest in (western and southern) Hudson Bay area and Chukchi/Bering Sea. In contrast, concentrations of Cd showed an increasing trend from east to west. Minor or no spatial trends were observed for Cu, Mn, Rb and Zn. Spatial trends were in agreement with previous studies, possibly explained by natural phenomena. To assess temporal changes of Cd, Hg, Se and Zn concentrations during the last decades, we compared our results to previously published data. These time comparisons suggested recent Hg increase in East Greenland polar bears. This may be related to Hg emissions and/or climate-induced changes in Hg cycles or changes in the polar bear food web related to global warming. Also, Hg:Se molar ratio has increased in East Greenland polar bears, which suggests there may be an increased risk for Hg 2+-mediated toxicity. Since the underlying reasons for spatial trends or changes in time of trace elements in the Arctic are still largely unknown, future studies should focus on the role of changing climate and trace metal emissions on geographical and temporal trends of trace elements. ?? 2011 The Royal Society of Chemistry.

Acute toxicity of polybrominated diphenyl ethers (PBDEs) for turbot (Psetta maxima) early life stages (ELS).

PubMed

Mhadhbi, Lazhar; Fumega, José; Boumaiza, Moncef; Beiras, Ricardo

2012-03-01

The environmental presence of polybrominated diphenyl ethers (PBDEs), among which BDE-47 and BDE-99 are particularly abundant, makes toxicity data necessary to assess the hazard risk posed by PBDE to aquatic organisms. This study examines the effects of BDE-47 and BDE-99 on embryo-larval stages of the marine flatfish turbot. The turbot embryos were exposed at nominal concentrations of BDE-47 and BDE-99 for 6 days. Selected dose levels were relevant for investigating sublethal and lethal effects. Both tested compounds caused lethal toxicity as well as non-lethal malformations during embryo development. We found a high toxic potency of BDE-47 compared to BDE-99 (LC₅₀ values for embryos and larvae, respectively, BDE-47: 27.35 and 14.13 μg L⁻¹; BDE-99: 38.28 and 29.64 μg L⁻¹). The present study shows high sensitivity of fish early life stages (ELS) to PBDE compounds. Based on environmental concentrations of dissolved PBDEs from various aquatic ecosystems, waterborne BDE-47 and BDE-99 pose little risk of acute toxicity to marine fish at relevant environmental concentrations. Turbot fish ELS proved to be an excellent model for the study of ecotoxicity of contaminants in seawater. The results demonstrate harmful effects of PBDE on turbot ELS at concentrations in the range of parts per billion units. In the perspective of risk assessment, ELS endpoints provide rapid, cost-effective and ecologically relevant information, and links should be sought between these short-term tests and effects of long-term exposures in more realistic scenarios.

Histopathology of experimental scuticociliatosis in turbot Scophthalmus maximus.

PubMed

Puig, L; Traveset, R; Palenzuela, O; Padrós, F

2007-06-29

A scuticociliate strain (B-2), originally isolated from an outbreak in a turbot Scophthalmus maximus (= Psetta maxima) farm in Galicia (northwestern Spain) and maintained in axenic culture, was injected intracoelomically (lethal dose 80 equivalent, LD80) in healthy turbot (50 g). Ciliate-injected fish were kept under controlled conditions in a recirculating seawater system and sampled on Days 1 through 8, 10, 12 and 14 postinfection (PI). Necropsies were conducted and included blood collection from the caudal vein and samples of liver, spleen, heart, digestive tract, kidney, gills, abdominal wall and neurocranium taken for routine histology. Mortality occurred from Day 6 until Day 12 PI and reached 66.7% by the end of the experiment. Presence of ciliates in the coelomic fluid was scarce until Day 4 PI. Parasitaemia was only observed from Day 5 until Day 10 PI and its incidence was always low. Presence of scuticociliates in tissue sections followed a progressive pattern of diffusion, with ciliates showing preference for loose connective tissue and also a clear haematophagous activity. The most severely affected organs were the pancreas and digestive tract. No special tropism for nervous tissues was observed in this study. The inflammatory reaction was variable depending on the tissue. After 3 wk, survivors had apparently managed to extinguish the infection.

Development and application of a tyrosinase-based time-temperature indicator (TTI) for determining the quality of turbot sashimi

NASA Astrophysics Data System (ADS)

Xu, Fengjuan; Ge, Lei; Li, Zhenxing; Lin, Hong; Mao, Xiangzhao

2017-10-01

Time-temperature indicators (TTIs) are convenient intuitive devices that are widely used to predict food quality. The aim of this study is to develop a new simple device which can be attached to food packages as a quality indicator for turbot sashimi. In this study, a solid TTI based on the reaction between tyrosinase and tyrosine was developed. The Arrhenius behavior of this enzymatic TTI was studied. The kinetics of the tyrosinase-based TTI was investigated in the form of color change from colorless to dark black induced by the enzymatic reaction. The mathematical formula for the color alterations as a function of time and temperature was established. The longest indication time for the developed TTI was 50 hours at 4°C. The activation energy of the tyrosinase-based TTI was 0.409 kJ mol-1. The suitability of the tyrosinase-based TTI was validated for turbot sashimi using total plate count. The feasibility of using this TTI as a quality indicator for turbot sashimi was assessed based on the activation energy and indication time. Therefore, the tyrosinasebased TTI system developed in this study could be used as an effective tool for monitoring the quality changes of turbot sashimi during the distribution and storage.

High-Throughput Sequence Analysis of Turbot (Scophthalmus maximus) Transcriptome Using 454-Pyrosequencing for the Discovery of Antiviral Immune Genes

PubMed Central

Pereiro, Patricia; Balseiro, Pablo; Romero, Alejandro; Dios, Sonia; Forn-Cuni, Gabriel; Fuste, Berta; Planas, Josep V.; Beltran, Sergi; Novoa, Beatriz; Figueras, Antonio

2012-01-01

Background Turbot (Scophthalmus maximus L.) is an important aquacultural resource both in Europe and Asia. However, there is little information on gene sequences available in public databases. Currently, one of the main problems affecting the culture of this flatfish is mortality due to several pathogens, especially viral diseases which are not treatable. In order to identify new genes involved in immune defense, we conducted 454-pyrosequencing of the turbot transcriptome after different immune stimulations. Methodology/Principal Findings Turbot were injected with viral stimuli to increase the expression level of immune-related genes. High-throughput deep sequencing using 454-pyrosequencing technology yielded 915,256 high-quality reads. These sequences were assembled into 55,404 contigs that were subjected to annotation steps. Intriguingly, 55.16% of the deduced protein was not significantly similar to any sequences in the databases used for the annotation and only 0.85% of the BLASTx top-hits matched S. maximus protein sequences. This relatively low level of annotation is possibly due to the limited information for this specie and other flatfish in the database. These results suggest the identification of a large number of new genes in turbot and in fish in general. A more detailed analysis showed the presence of putative members of several innate and specific immune pathways. Conclusions/Significance To our knowledge, this study is the first transcriptome analysis using 454-pyrosequencing for turbot. Previously, there were only 12,471 EST and less of 1,500 nucleotide sequences for S. maximus in NCBI database. Our results provide a rich source of data (55,404 contigs and 181,845 singletons) for discovering and identifying new genes, which will serve as a basis for microarray construction, gene expression characterization and for identification of genetic markers to be used in several applications. Immune stimulation in turbot was very effective, obtaining an

An Expressed Sequence Tag (EST)-enriched genetic map of turbot (Scophthalmus maximus): a useful framework for comparative genomics across model and farmed teleosts

PubMed Central

2012-01-01

Background The turbot (Scophthalmus maximus) is a relevant species in European aquaculture. The small turbot genome provides a source for genomics strategies to use in order to understand the genetic basis of productive traits, particularly those related to sex, growth and pathogen resistance. Genetic maps represent essential genomic screening tools allowing to localize quantitative trait loci (QTL) and to identify candidate genes through comparative mapping. This information is the backbone to develop marker-assisted selection (MAS) programs in aquaculture. Expressed sequenced tag (EST) resources have largely increased in turbot, thus supplying numerous type I markers suitable for extending the previous linkage map, which was mostly based on anonymous loci. The aim of this study was to construct a higher-resolution turbot genetic map using EST-linked markers, which will turn out to be useful for comparative mapping studies. Results A consensus gene-enriched genetic map of the turbot was constructed using 463 SNP and microsatellite markers in nine reference families. This map contains 438 markers, 180 EST-linked, clustered at 24 linkage groups. Linkage and comparative genomics evidences suggested additional linkage group fusions toward the consolidation of turbot map according to karyotype information. The linkage map showed a total length of 1402.7 cM with low average intermarker distance (3.7 cM; ~2 Mb). A global 1.6:1 female-to-male recombination frequency (RF) ratio was observed, although largely variable among linkage groups and chromosome regions. Comparative sequence analysis revealed large macrosyntenic patterns against model teleost genomes, significant hits decreasing from stickleback (54%) to zebrafish (20%). Comparative mapping supported particular chromosome rearrangements within Acanthopterygii and aided to assign unallocated markers to specific turbot linkage groups. Conclusions The new gene-enriched high-resolution turbot map represents a

Trophic transfer and accumulation of TiO2 nanoparticles from clamworm (Perinereis aibuhitensis) to juvenile turbot (Scophthalmus maximus) along a marine benthic food chain.

PubMed

Wang, Zhenyu; Yin, Liyun; Zhao, Jian; Xing, Baoshan

2016-05-15

In the present work, we investigated the potential benthic trophic transfer of TiO2 nanoparticles (NPs) from clamworm (Perinereis aibuhitensis) to juvenile turbot (Scophthalmus maximus) and their related distribution and toxicity. TiO2 NPs (at 10, 50 and 100 mg/L) could be taken up by clamworms, and mainly accumulated in the lower-digestive tract. TiO2 NPs were able to transfer from clamworms to juvenile turbots. The accumulation of TiO2 NPs in juvenile turbots increased with increasing Ti contents in clamworms during the dietary exposure, however, no biomagnification (BMFs, 0.30-0.33) of TiO2 NPs was observed. For both dietary and waterborne exposure, accumulation of TiO2 NPs was higher in the gill, intestine and stomach of juvenile turbot, following by skin, liver, and muscle. During dietary exposure at Day 20, the growth of turbots was reduced, and abnormal symptoms of liver and spleen were detected. Moreover, both dietary (50 and 100 mg/L TiO2 NPs-treated clamworms) and waterborne (100 mg/L TiO2 NPs) exposures led to significantly lower protein and higher lipid contents, suggesting the nutrition quality reduction of turbots. The findings from this work highlighted the trophic transfer of TiO2 NPs in marine benthic food chain, leading to the potential negative impact on marine aquaculture and food quality. Copyright © 2016 Elsevier Ltd. All rights reserved.

Transcriptome Profiles Associated to VHSV Infection or DNA Vaccination in Turbot (Scophthalmus maximus)

PubMed Central

Pereiro, Patricia; Dios, Sonia; Boltaña, Sebastián; Coll, Julio; Estepa, Amparo; Mackenzie, Simon; Novoa, Beatriz; Figueras, Antonio

2014-01-01

DNA vaccines encoding the viral G glycoprotein show the most successful protection capability against fish rhabdoviruses. Nowadays, the molecular mechanisms underlying the protective response remain still poorly understood. With the aim of shedding light on the protection conferred by the DNA vaccines based in the G glycoprotein of viral haemorrhagic septicaemia virus (VHSV) in turbot (Scophthalmus maximus) we have used a specific microarray highly enriched in antiviral sequences to carry out the transcriptomic study associated to VHSV DNA vaccination/infection. The differential gene expression pattern in response to empty plasmid (pMCV1.4) and DNA vaccine (pMCV1.4-G860) intramuscular administration with regard to non-stimulated turbot was analyzed in head kidney at 8, 24 and 72 hours post-vaccination. Moreover, the effect of VHSV infection one month after immunization was also analyzed in vaccinated and non-vaccinated fish at the same time points. Genes implicated in the Toll-like receptor signalling pathway, IFN inducible/regulatory proteins, numerous sequences implicated in apoptosis and cytotoxic pathways, MHC class I antigens, as well as complement and coagulation cascades among others were analyzed in the different experimental groups. Fish receiving the pMCV1.4-G860 vaccine showed transcriptomic patterns very different to the ones observed in pMCV1.4-injected turbot after 72 h. On the other hand, VHSV challenge in vaccinated and non-vaccinated turbot induced a highly different response at the transcriptome level, indicating a very relevant role of the acquired immunity in vaccinated fish able to alter the typical innate immune response profile observed in non-vaccinated individuals. This exhaustive transcriptome study will serve as a complete overview for a better understanding of the crosstalk between the innate and adaptive immune response in fish after viral infection/vaccination. Moreover, it provides interesting clues about molecules with a potential

Molecular Analysis of Endocrine Disruption in Hornyhead Turbot at Wastewater Outfalls in Southern California Using a Second Generation Multi-Species Microarray

PubMed Central

Baker, Michael E.; Vidal-Dorsch, Doris E.; Ribecco, Cataldo; Sprague, L. James; Angert, Mila; Lekmine, Narimene; Ludka, Colleen; Martella, Andrea; Ricciardelli, Eugenia; Bay, Steven M.; Gully, Joseph R.; Kelley, Kevin M.; Schlenk, Daniel; Carnevali, Oliana; Šášik, Roman; Hardiman, Gary

2013-01-01

Sentinel fish hornyhead turbot ( Pleuronichthys verticalis ) captured near wastewater outfalls are used for monitoring exposure to industrial and agricultural chemicals of ~ 20 million people living in coastal Southern California. Although analyses of hormones in blood and organ morphology and histology are useful for assessing contaminant exposure, there is a need for quantitative and sensitive molecular measurements, since contaminants of emerging concern are known to produce subtle effects. We developed a second generation multi-species microarray with expanded content and sensitivity to investigate endocrine disruption in turbot captured near wastewater outfalls in San Diego, Orange County and Los Angeles California. Analysis of expression of genes involved in hormone [e.g., estrogen, androgen, thyroid] responses and xenobiotic metabolism in turbot livers was correlated with a series of phenotypic end points. Molecular analyses of turbot livers uncovered altered expression of vitellogenin and zona pellucida protein, indicating exposure to one or more estrogenic chemicals, as well as, alterations in cytochrome P450 (CYP) 1A, CYP3A and glutathione S-transferase-α indicating induction of the detoxification response. Molecular responses indicative of exposure to endocrine disruptors were observed in field-caught hornyhead turbot captured in Southern California demonstrating the utility of molecular methods for monitoring environmental chemicals in wastewater outfalls. Moreover, this approach can be adapted to monitor other sites for contaminants of emerging concern in other fish species for which there are few available gene sequences. PMID:24086568

Towards the inversion of GRACE gravity fields for present-day ice-mass changes and glacial-isostatic adjustment in North America and Greenland

NASA Astrophysics Data System (ADS)

Sasgen, Ingo; Klemann, Volker; Martinec, Zdeněk

2012-09-01

We perform an inversion of gravity fields from the Gravity Recovery and Climate Experiment (GRACE) (August 2002 to August 2009) of four processing centres for glacial-isostatic adjustment (GIA) over North America and present-day ice-mass change in Alaska and Greenland. We apply a statistical filtering approach to reduce noise in the GRACE data by confining our investigations to GRACE coefficients containing a statistically significant linear trend. Selecting the subset of reliable coefficients in all GRACE time series (GFZ RL04, ITG 2010, JPL RL04 and CSR RL04) results in a non-isotropic smoothing of the GRACE gravity fields, which is effective in reducing the north-south oriented striping associated with correlated errors in GRACE coefficients. In a next step, forward models of GIA induced by the glacial history NAWI (Zweck and Huybrechts, 2005), as well as present-day ice mass changes in Greenland from ICESat (Sørensen et al., 2011) and Alaska from airborne laser altimetry (Arendt et al., 2002) are simultaneously adjusted in scale to minimize the misfit to the filtered GRACE trends. From the adjusted models, we derive the recent sea-level contributions for Greenland and Alaska (August 2002 to August 2009), and, interpret the residual misfit over the GIA-dominated region around the Hudson Bay, Canada, in terms of mantle viscosities beneath North America.

The peopling of Greenland: further insights from the analysis of genetic diversity using autosomal and X-chromosomal markers

PubMed Central

Pereira, Vania; Tomas, Carmen; Sanchez, Juan J; Syndercombe-Court, Denise; Amorim, António; Gusmão, Leonor; Prata, Maria João; Morling, Niels

2015-01-01

The peopling of Greenland has a complex history shaped by population migrations, isolation and genetic drift. The Greenlanders present a genetic heritage with components of European and Inuit groups; previous studies using uniparentally inherited markers in Greenlanders have reported evidence of a sex-biased, admixed genetic background. This work further explores the genetics of the Greenlanders by analysing autosomal and X-chromosomal data to obtain deeper insights into the factors that shaped the genetic diversity in Greenlanders. Fourteen Greenlandic subsamples from multiple geographical settlements were compared to assess the level of genetic substructure in the Greenlandic population. The results showed low levels of genetic diversity in all sets of the genetic markers studied, together with an increased number of X-chromosomal loci in linkage disequilibrium in relation to the Danish population. In the broader context of worldwide populations, Greenlanders are remarkably different from most populations, but they are genetically closer to some Inuit groups from Alaska. Admixture analyses identified an Inuit component in the Greenlandic population of approximately 80%. The sub-populations of Ammassalik and Nanortalik are the least diverse, presenting the lowest levels of European admixture. Isolation-by-distance analyses showed that only 16% of the genetic substructure of Greenlanders is most likely to be explained by geographic barriers. We suggest that genetic drift and a differentiated settlement history around the island explain most of the genetic substructure of the population in Greenland. PMID:24801759

The peopling of Greenland: further insights from the analysis of genetic diversity using autosomal and X-chromosomal markers.

PubMed

Pereira, Vania; Tomas, Carmen; Sanchez, Juan J; Syndercombe-Court, Denise; Amorim, António; Gusmão, Leonor; Prata, Maria João; Morling, Niels

2015-02-01

The peopling of Greenland has a complex history shaped by population migrations, isolation and genetic drift. The Greenlanders present a genetic heritage with components of European and Inuit groups; previous studies using uniparentally inherited markers in Greenlanders have reported evidence of a sex-biased, admixed genetic background. This work further explores the genetics of the Greenlanders by analysing autosomal and X-chromosomal data to obtain deeper insights into the factors that shaped the genetic diversity in Greenlanders. Fourteen Greenlandic subsamples from multiple geographical settlements were compared to assess the level of genetic substructure in the Greenlandic population. The results showed low levels of genetic diversity in all sets of the genetic markers studied, together with an increased number of X-chromosomal loci in linkage disequilibrium in relation to the Danish population. In the broader context of worldwide populations, Greenlanders are remarkably different from most populations, but they are genetically closer to some Inuit groups from Alaska. Admixture analyses identified an Inuit component in the Greenlandic population of approximately 80%. The sub-populations of Ammassalik and Nanortalik are the least diverse, presenting the lowest levels of European admixture. Isolation-by-distance analyses showed that only 16% of the genetic substructure of Greenlanders is most likely to be explained by geographic barriers. We suggest that genetic drift and a differentiated settlement history around the island explain most of the genetic substructure of the population in Greenland.

Combined antiparasitic and anti-inflammatory effects of the natural polyphenol curcumin on turbot scuticociliatosis.

PubMed

Mallo, N; DeFelipe, A P; Folgueira, I; Sueiro, R A; Lamas, J; Leiro, J M

2017-02-01

The histiophagous scuticociliate Philasterides dicentrarchi is the aetiological agent of scuticociliatosis, a parasitic disease of farmed turbot. Curcumin, a polyphenol from Curcuma longa (turmeric), is known to have antioxidant and anti-inflammatory properties. We investigated the in vitro effects of curcumin on the growth of P. dicentrarchi and on the production of pro-inflammatory cytokines in turbot leucocytes activated by parasite cysteine proteases. At 100 μm, curcumin had a cytotoxic effect and completely inhibited the growth of the parasite. At 50 μm, curcumin inhibited the protease activity of the parasite and expression of genes encoding two virulence-associated proteases: leishmanolysin-like peptidase and cathepsin L-like. At concentrations between 25 and 50 μm, curcumin inhibited the expression of S-adenosyl-L-homocysteine hydrolase, an enzyme involved in the biosynthesis of the amino acids methionine and cysteine. At 100 μm, curcumin inhibited the expression of the cytokines tumour necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) produced in turbot leucocytes activated by parasite proteases. Results show that curcumin has a dual effect on scuticociliatosis: an antiparasitic effect on the catabolism and anabolism of ciliate proteins, and an anti-inflammatory effect that inhibits the production of proinflammatory cytokines in the host. The present findings suggest the potential usefulness of this polyphenol in treating scuticociliatosis. © 2016 John Wiley & Sons Ltd.

Effect of stocking density on performances of juvenile turbot ( Scophthalmus maximus) in recirculating aquaculture systems

NASA Astrophysics Data System (ADS)

Li, Xian; Liu, Ying; Blancheton, Jean-Paul

2013-05-01

Limited information has been available about the influence of loading density on the performances of Scophthalmus maximus, especially in recirculating aquaculture systems (RAS). In this study, turbot (13.84±2.74 g; average weight±SD) were reared at four different initial densities (low 0.66, medium 1.26, sub-high 2.56, high 4.00 kg/m2) for 10 weeks in RAS at 23±1°C. Final densities were 4.67, 7.25, 14.16, and 17.47 kg/m2, respectively, which translate to 82, 108, 214, and 282 percent coverage of the tank bottom. Density had both negative and independent impacts on growth. The final mean weight, specific growth rate (SGR), and voluntary feed intake significantly decreased and the coefficient of variation (CV) of final body weight increased with increase in stocking density. The medium and sub-high density groups did not differ significantly in SGR, mean weight, CV, food conversion rate (FCR), feed intake, blood parameters, and digestive enzymes. The protease activities of the digestive tract at pH 7, 8.5, 9, and 10 were significantly higher for the highest density group, but tended to be lower (not significantly) at pH 4 and 8.5 for the lowest density group. The intensity of protease activity was inversely related to feed intake at the different densities. Catalase activity was higher (but not significantly) at the highest density, perhaps because high density started to induce an oxidative effect in turbot. In conclusion, turbot can be cultured in RAS at a density of less than 17.47 kg/m2. With good water quality and no feed limitation, initial density between 1.26 and 2.56 kg/m2 (final: 7.25 and 14.16 kg/m2) would not negatively affect the turbot cultured in RAS. For culture at higher density, multi-level feeding devices are suggested to ease feeding competition.

Tissue Localization of Lymphocystis Disease Virus (LCDV) Receptor-27.8 kDa and Its Expression Kinetics Induced by the Viral Infection in Turbot (Scophthalmus maximus)

PubMed Central

Sheng, Xiuzhen; Wu, Ronghua; Tang, Xiaoqian; Xing, Jing; Zhan, Wenbin

2015-01-01

The 27.8 kDa membrane protein expressed in flounder (Paralichthys olivaceus) gill cells was proved to be a receptor mediating lymphocystis disease virus (LCDV) infection. In this study, SDS-PAGE and Western blotting demonstrated that 27.8 kDa receptor (27.8R) was shared by flounder and turbot (Scophthalmus maximus). Indirect immunofluorescence assay (IIFA) and immunohistochemistry showed that 27.8R was widely expressed in tested tissues of healthy turbot. The indirect enzyme-linked immunosorbent assay indicated that 27.8R expression was relatively higher in stomach, gill, heart, and intestine, followed by skin, head kidney, spleen, blood cells, kidney and liver, and lower in ovary and brain in healthy turbot, and it was significantly up-regulated after LCDV infection. Meanwhile, real-time quantitative PCR demonstrated that LCDV was detected in heart, peripheral blood cells, and head kidney at 3 h post infection (p.i.), and then in other tested tissues at 12 h p.i. LCDV copies increased in a time-dependent manner, and were generally higher in the tissues with higher 27.8R expression. Additionally, IIFA showed that 27.8R and LCDV were detected at 3 h p.i. in some leukocytes. These results suggested that 27.8R also served as a receptor in turbot, and LCDV can infect some leukocytes which might result in LCDV spreading to different tissues in turbot. PMID:26556346

Tissue Localization of Lymphocystis Disease Virus (LCDV) Receptor-27.8 kDa and Its Expression Kinetics Induced by the Viral Infection in Turbot (Scophthalmus maximus).

PubMed

Sheng, Xiuzhen; Wu, Ronghua; Tang, Xiaoqian; Xing, Jing; Zhan, Wenbin

2015-11-05

The 27.8 kDa membrane protein expressed in flounder (Paralichthys olivaceus) gill cells was proved to be a receptor mediating lymphocystis disease virus (LCDV) infection. In this study, SDS-PAGE and Western blotting demonstrated that 27.8 kDa receptor (27.8R) was shared by flounder and turbot (Scophthalmus maximus). Indirect immunofluorescence assay (IIFA) and immunohistochemistry showed that 27.8R was widely expressed in tested tissues of healthy turbot. The indirect enzyme-linked immunosorbent assay indicated that 27.8R expression was relatively higher in stomach, gill, heart, and intestine, followed by skin, head kidney, spleen, blood cells, kidney and liver, and lower in ovary and brain in healthy turbot, and it was significantly up-regulated after LCDV infection. Meanwhile, real-time quantitative PCR demonstrated that LCDV was detected in heart, peripheral blood cells, and head kidney at 3 h post infection (p.i.), and then in other tested tissues at 12 h p.i. LCDV copies increased in a time-dependent manner, and were generally higher in the tissues with higher 27.8R expression. Additionally, IIFA showed that 27.8R and LCDV were detected at 3 h p.i. in some leukocytes. These results suggested that 27.8R also served as a receptor in turbot, and LCDV can infect some leukocytes which might result in LCDV spreading to different tissues in turbot.

Outbreak of trichinellosis associated with consumption of game meat in West Greenland.

PubMed

Møller, Lone Nukâraq; Petersen, Eskild; Kapel, Christian M O; Melbye, Mads; Koch, Anders

2005-09-05

The Inuit population of the Arctic has always been at risk of acquiring trichinellosis and severe outbreaks have been recorded in Alaska and Canada. In West Greenland, a number of large outbreaks took place during the 1940s and 1950s; they involved total 420 cases including 37 deaths. Since then only sporadic cases have been reported. Here, we describe an outbreak of infection with Trichinella spp. after consumption of infected meat presumably from walrus or polar bear caught in western Greenland. Six persons who had eaten of the walrus and polar bear meat were two males and four females, age range 6--47 years. Using ELISA and Western blot analysis (Trichinella-specific IgG antibodies against excreted/secreted antigen and synthetic tyvelose antigen, respectively) four of these persons were found to be sero-positive for Trichinella antibodies, with three of these having clinical symptoms compatible with trichinellosis. On re-test, 12--14 months later one of the two sero-negative persons had sero-converted, probably due to a new, unrelated infection. This study demonstrates that acquiring Trichinella from the consumption of marine mammals remains a possibility in Greenland, and that cases may go undetected. Trichinellosis in Greenland can be prevented by the implementation of public health measures.

Natural Chemical Composition of Commercial Fish Species: Characterisation of Pangasius, Wild and Farmed Turbot and Barramundi

PubMed Central

Manthey-Karl, Monika; Lehmann, Ines; Ostermeyer, Ute; Schröder, Ute

2016-01-01

To comply with the relevant legal requirements and correct labelling, it is necessary for business operators and inspection authorities to know the natural characteristics of the raw material. This study gives a comprehensive overview of muscle flesh composition of farmed and wild Atlantic turbot (Scophthalmus maximus) and barramundi (Lates calcarifer) and of farmed pangasius (Pangasianodon hypophthalmus). The proximate composition, di- and triphosphates and citric acid values are presented in order to evaluate possible indicators for a hidden treatment during processing to fillets. All moisture contents were ≤80%. Even for pangasius, protein values for deep skinned fillets of ≥18% were determined. Only small quantities of naturally occurring citric acid (up to 0.03 g·kg−1) were detectable. The lipid content was the most varying main component within the different species, ranging between 1.2% to 2.0% and 0.3% to 3.0% for farmed turbot and barramundi, respectively. Pangasius flesh had a mean lipid content of 7.8%. Trimming and separation of the red layer reduced the lipid content of the commercially sold white-flesh fillets to 2.7% to 3.5%. Fatty acids profiles, free amino acids, and minerals were analysed to show the nutritional quality of the aquaculture fish species and compared to wild turbot and barramundi. Despite some natural variation, these components can be considered as comparable. PMID:28231154

Antarctica, Greenland and Gulf of Alaska Land-ice Evolution from an Iterated GRACE Global Mascon Solution

NASA Technical Reports Server (NTRS)

Luthcke, Scott B.; Sabaka, T. J.; Loomis, B. D.; Arendt, A. A.; McCarthy, J. J.; Camp, J.

2013-01-01

We have determined the ice mass evolution of the Antarctica and Greenland ice sheets (AIS and GIS) and Gulf of Alaska (GOA) glaciers from a new GRACE global solution of equal-area surface mass concentration parcels (mascons) in equivalent height of water. The mascons were estimated directly from the reduction of the inter-satellite K-band range-rate (KBRR) observations, taking into account the full noise covariance, and formally iterating the solution. The new solution increases signal recovery while reducing the GRACE KBRR observation residuals. The mascons were estimated with 10 day and 1 arc degree equal-area sampling, applying anisotropic constraints. An ensemble empirical mode decomposition adaptive filter was applied to the mascon time series to compute annual mass balances. The details and causes of the spatial and temporal variability of the land-ice regions studied are discussed. The estimated mass trend over the total GIS, AIS and GOA glaciers for the time period 1 December 2003 to 1 December 2010 is -380 plus or minus 31 Gt a(exp -1), equivalent to -1.05 plus or minus 0.09 mma(exp -1) sea-level rise. Over the same time period we estimate the mass acceleration to be -41 plus or minus 27 Gt a(exp -2), equivalent to a 0.11 plus or minus 0.08 mm a(exp -2) rate of change in sea level. The trends and accelerations are dependent on significant seasonal and annual balance anomalies.

Antarctica, Greenland and Gulf of Alaska Land-Ice Evolution from an Iterated GRACE Global Mascon Solution

NASA Technical Reports Server (NTRS)

Luthcke, Scott B.; Sabaka, T. J.; Loomis, B. D.; Arendt, A. A.; McCarthy, J. J.; Camp, J.

2013-01-01

We have determined the ice mass evolution of the Antarctica and Greenland ice sheets (AIS and GIS) and Gulf of Alaska (GOA) glaciers from a new GRACE global solution of equal-area surface mass concentration parcels (mascons) in equivalent height of water. The mascons were estimated directly from the reduction of the inter-satellite K-band range-rate (KBRR) observations, taking into account the full noise covariance, and formally iterating the solution. The new solution increases signal recovery while reducing the GRACE KBRR observation residuals. The mascons were estimated with 10 day and 1 arc degree equal-area sampling, applying anisotropic constraints. An ensemble empirical mode decomposition adaptive filter was applied to the mascon time series to compute annual mass balances. The details and causes of the spatial and temporal variability of the land-ice regions studied are discussed. The estimated mass trend over the total GIS, AIS and GOA glaciers for the time period 1 December 2003 to 1 December 2010 is -380 plus or minus 31 Gt a(exp -1), equivalent to -1.05 plus or minus 0.09 mma(exp -1) sea-level rise. Over the same time period we estimate the mass acceleration to be -41 plus or minus 27 Gt a(exp -2), equivalent to a 0.11 plus or minus 0.08 mm a(exp -2) rate of change in sea level. The trends and accelerations are dependent on significant seasonal and annual balance anomalies.

Expression analysis of the insulin-like growth factors I and II during embryonic and early larval development of turbot ( Scophthalmus maximus)

NASA Astrophysics Data System (ADS)

Wen, Haishen; Qi, Qian; Hu, Jian; Si, Yufeng; He, Feng; Li, Jifang

2015-04-01

The insulin-like growth factors I and II (IGF-I and IGF-II) are important proteins involved in fish growth and development. Here, we report the isolation of IGF-II and expression analysis of IGFs in turbot Scophthalmus maximus, aiming to clarify their function in embryonic and larval development of fish. The deduced IGF-II gene is 808 bp in full length, which encodes a protein of 219 amino acids and is 93% similar with that of Paralichthys olicaceus in amino acid sequence. The tissue abundance and the expression pattern of IGFs in a turbot at early development stages were investigated via reverse transcription-polymer chain reaction. Result showed that the IGF-I and IGF-II genes were widely expressed in tissues of S. maximus. IGF-I was detected in all tissues except intestines with the highest level in liver, while IGF-II transcript presented in all tissues except muscle. At the stages of embryonic and larval development, the mRNA levels of IGFs sharply increased from the stage of unfertilized egg to post larva, followed by a decrease with larval development. However, there was an increase in IGF-I at the embryonic stage and IGF-II at the gastrula stage, respectively. These results suggested that IGFs play important roles in cell growth and division of the turbot. Our study provides reference data for further investigation of growth regulation in turbot, which can guarantee better understanding of the physiological role that IGFs play in fish.

Characterization and differential expression of three GnRH forms during reproductive development in cultured turbot Schophthalmus maximus

NASA Astrophysics Data System (ADS)

Zhao, Chunyan; Xu, Shihong; Feng, Chengcheng; Liu, Yifan; Yang, Yang; Wang, Yanfeng; Xiao, Yongshuang; Song, Zongcheng; Liu, Qinghua; Li, Jun

2017-10-01

Turbots (Schophthalmus maximus), one of the most important economic marine flatfish species, fail to undergo final spawning and spermiation naturally under artificial farming conditions. In vertebrates, reproduction is regulated by the brain-pituitary-gonadal axis (BPG-axis), and gonadotropin releasing hormone (GnRH) is one of its key components. Therefore, to better understand the physiology of reproduction in the turbot, three of the genes encoding GnRH subtypes—sbGnRH, cGnRH-II and sGnRH—were cloned and sequenced by isolating the cDNA sequences. The localizations and patterns of expression of their mRNAs were also evaluated during seasonal gonadal development. All three mRNAs were expressed abundantly in the brain; sbGnRH and sGnRH mRNAs were also detected in the gonads and pituitary gland, and sbGnRH expression was much higher than that of sGnRH, indicating the critical role of sbGnRH in regulating the BPG-axis. Moreover, the brain expression patterns of sbGnRH and sGnRH mRNAs showed an increased trend during gonadal development, peaking in mature stages. This indicated the direct regulation of gonadal development by the GnRH system. In addition, cGnRH-II mRNA expression showed no significant variations, suggesting that cGnRH-II is not critically involved in the control of reproduction. Further, the mRNA abundances of the three GnRH forms in the breeding season were significantly higher than those in immature and post-breeding stages in all analyzed brain areas. Therefore, we propose that sbGnRH is the most important hormone for the regulation of reproduction in turbot via the BPG-axis. These results will help in better understanding the reproductive endocrine mechanisms of turbots and lay the groundwork for additional studies aimed at comparing the reproductive physiology of wild individuals with those raised under artificial conditions.

Geographic distribution of selected elements in the livers of polar bears from Greenland, Canada and the United States.

PubMed

Rush, Scott A; Borgå, Katrine; Dietz, Rune; Born, Erik W; Sonne, Christian; Evans, Thomas; Muir, Derek C G; Letcher, Robert J; Norstrom, Ross J; Fisk, Aaron T

2008-06-01

To assess geographic distributions of elements in the Arctic we compared essential and non-essential elements in the livers of polar bears (Ursus maritimus) collected from five regions within Canada in 2002, in Alaska between 1994 and 1999 and from the northwest and east coasts of Greenland between 1988 and 2000. As, Hg, Pb and Se varied with age, and Co and Zn with gender, which limited spatial comparisons across all populations to Cd, which was highest in Greenland bears. Collectively, geographic relationships appeared similar to past studies with little change in concentration over time in Canada and Greenland for most elements; Hg and Se were higher in some Canadian populations in 2002 as compared to 1982 and 1984. Concentrations of most elements in the polar bears did not exceed toxicity thresholds, although Cd and Hg exceeded levels correlated with the formation of hepatic lesions in laboratory animals.

Interaction of temperature and salinity on the expression of immunity factors in different tissues of juvenile turbot Scophthalmus maximus based on response surface methodology

NASA Astrophysics Data System (ADS)

Huang, Zhihui; Ma, Aijun; Wang, Xin'an; Lei, Jilin; Li, Weiye; Wang, Ting; Yang, Zhi; Qu, Jiangbo

2015-01-01

Central Composite Design (CCD) and response surface methodology were used in the experiment to examine the combined effect of temperature (16-28°C) and salinity (18-42) on Hsp70 and IgM genes expression levels in turbot ( Scophthalmus maximus) liver and kidney. The results showed that the coefficients of determination ( R 2 =0.965 2 for liver Hsp70, 0.972 9 for kidney Hsp70, 0.921 for liver IgM and 0.962 1 for kidney IgM) and probability values ( P<0.01) were significant for the regression model. The interactive effect between temperature and salinity on liver Hsp70, kidney Hsp70 and liver IgM were not significant ( P>0.05), while the interactive effect between temperature and salinity on kidney IgM was significant ( P<0.01). The model equation could be used in practice for forecasting Hsp70 and IgM genes expression levels in the liver and kidney of juvenile turbot via applying statistical optimization of the response of interest, at which the maximum liver Hsp70, kidney Hsp70, liver IgM and kidney IgM of 1.48, 1.49, 2.48, and 1.38, respectively, were reached. The present model may be valuable in assessing the feasibility of turbot farming at different geographic locations and, furthermore, could be a useful reference for scientists studying the immunity of turbot.

Effect of dietary vitamin E on the sperm quality of turbot ( Scophthalmus maximus)

NASA Astrophysics Data System (ADS)

Xu, Houguo; Huang, Lina; Liang, Mengqing; Zheng, Keke; Wang, Xinxing

2015-08-01

A 3-month feeding experiment was conducted in an in-door seawater system to investigate the effect of dietary vitamin E (Ve) on the sperm quality of turbot ( Scophthalmus maximus). D-α-tocopherol acetate was supplemented to the basal (control) diet (65.14 mg kg-1 Ve) to obtain low and high levels of dietary Ve (244.60 mg kg-1, LVe; 721.60 mg kg-1, HVe). Compared with the control, sperm concentration was significantly increased in Ve-supplemented groups (LVe and HVe); while relative sperm volume and testis-somatic index were significantly increased in group HVe only. Sperm motility duration was significantly longer in group HVe than in the control, but no significant difference was observed in percent motility among groups. Sperm size, the uniformity of mitochondrial size, and the integrity of mitochondria cristae and plasma membrane were improved by dietary Ve, especially in HVe. The content of Ve in testis and liver as well as polyunsaturated fatty acids in sperm increased with dietary Ve. These results suggested that dietary Ve, especially at the high level (721.60 mg kg-1), significantly improved sperm concentration and motility duration and maintained normal sperm morphology of turbot.

Pharmacokinetics and tissue behavior of enrofloxacin and its metabolite ciprofloxacin in turbot Scophthalmus maximus at two water temperatures

NASA Astrophysics Data System (ADS)

Liang, Junping; Li, Jian; Zhao, Fazhen; Liu, Ping; Chang, Zhiqiang

2012-07-01

Turbot Scophthalmus maximus, an important aquaculture species in China, currently suffers from epizootic diseases because of high density aquaculture. Enrofloxacin has been used to treat various systemic bacterial fish infections. However, studies concerning the pharmacokinetics of enrofloxacin in turbot are limited. In this study, the pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin, were investigated in the turbot following intravenous and oral administration at 10 mg enrofloxacin/kg body weight, at 16°C and 10°C water temperatures. The concentrations of enrofloxacin and ciprofloxacin in the main tissues (plasma, muscle, liver and kidney) were detected by HPLC. The results show that the plasma concentration-time data for enrofloxacin were best described as a two-compartment open model after intravenous and oral administration. Three pharmacokinetic equations were established between the concentrations and temperatures. The kinetic profile of enrofloxacin was temperature dependent. The absorption half-life of enrofloxacin was 1.99 h and 2.17 h after oral administration, whereas the elimination half-life of the drug was 98.63 h and 136.59 h at 16°C and 10°C, respectively. The peak concentration of enrofloxacin in plasma and tissues was higher at 16°C than that at 10°C, and the peak plasma concentration time in the liver was the shortest at both temperatures among those of other tissues. The plasma C max /MIC ratio varied between 11.08 and 5 540.00 at 16°C; and between 7.92 and 3 960.00 at 10°C. The AUC/MIC ratio was 467.82-280 690.00 at 16°C, and 359.48-215 690.00 at 10°C. These ratios indicate that it is possible to obtain therapeutic efficacy. Very low levels of ciprofloxacin were detected. The AUC ratios of ciprofloxacin and enrofloxacin in plasma suggest that plasma ciprofloxacin might play a minor role in enrofloxacin treatment for turbot.

A combined strategy involving Sanger and 454 pyrosequencing increases genomic resources to aid in the management of reproduction, disease control and genetic selection in the turbot (Scophthalmus maximus).

PubMed

Ribas, Laia; Pardo, Belén G; Fernández, Carlos; Alvarez-Diós, José Antonio; Gómez-Tato, Antonio; Quiroga, María Isabel; Planas, Josep V; Sitjà-Bobadilla, Ariadna; Martínez, Paulino; Piferrer, Francesc

2013-03-15

Genomic resources for plant and animal species that are under exploitation primarily for human consumption are increasingly important, among other things, for understanding physiological processes and for establishing adequate genetic selection programs. Current available techniques for high-throughput sequencing have been implemented in a number of species, including fish, to obtain a proper description of the transcriptome. The objective of this study was to generate a comprehensive transcriptomic database in turbot, a highly priced farmed fish species in Europe, with potential expansion to other areas of the world, for which there are unsolved production bottlenecks, to understand better reproductive- and immune-related functions. This information is essential to implement marker assisted selection programs useful for the turbot industry. Expressed sequence tags were generated by Sanger sequencing of cDNA libraries from different immune-related tissues after several parasitic challenges. The resulting database ("Turbot 2 database") was enlarged with sequences generated from a 454 sequencing run of brain-hypophysis-gonadal axis-derived RNA obtained from turbot at different development stages. The assembly of Sanger and 454 sequences generated 52,427 consensus sequences ("Turbot 3 database"), of which 23,661 were successfully annotated. A total of 1,410 sequences were confirmed to be related to reproduction and key genes involved in sex differentiation and maturation were identified for the first time in turbot (AR, AMH, SRY-related genes, CYP19A, ZPGs, STAR FSHR, etc.). Similarly, 2,241 sequences were related to the immune system and several novel key immune genes were identified (BCL, TRAF, NCK, CD28 and TOLLIP, among others). The number of genes of many relevant reproduction- and immune-related pathways present in the database was 50-90% of the total gene count of each pathway. In addition, 1,237 microsatellites and 7,362 single nucleotide polymorphisms (SNPs

A combined strategy involving Sanger and 454 pyrosequencing increases genomic resources to aid in the management of reproduction, disease control and genetic selection in the turbot (Scophthalmus maximus)

PubMed Central

2013-01-01

Background Genomic resources for plant and animal species that are under exploitation primarily for human consumption are increasingly important, among other things, for understanding physiological processes and for establishing adequate genetic selection programs. Current available techniques for high-throughput sequencing have been implemented in a number of species, including fish, to obtain a proper description of the transcriptome. The objective of this study was to generate a comprehensive transcriptomic database in turbot, a highly priced farmed fish species in Europe, with potential expansion to other areas of the world, for which there are unsolved production bottlenecks, to understand better reproductive- and immune-related functions. This information is essential to implement marker assisted selection programs useful for the turbot industry. Results Expressed sequence tags were generated by Sanger sequencing of cDNA libraries from different immune-related tissues after several parasitic challenges. The resulting database (“Turbot 2 database”) was enlarged with sequences generated from a 454 sequencing run of brain-hypophysis-gonadal axis-derived RNA obtained from turbot at different development stages. The assembly of Sanger and 454 sequences generated 52,427 consensus sequences (“Turbot 3 database”), of which 23,661 were successfully annotated. A total of 1,410 sequences were confirmed to be related to reproduction and key genes involved in sex differentiation and maturation were identified for the first time in turbot (AR, AMH, SRY-related genes, CYP19A, ZPGs, STAR FSHR, etc.). Similarly, 2,241 sequences were related to the immune system and several novel key immune genes were identified (BCL, TRAF, NCK, CD28 and TOLLIP, among others). The number of genes of many relevant reproduction- and immune-related pathways present in the database was 50–90% of the total gene count of each pathway. In addition, 1,237 microsatellites and 7,362 single

50 CFR 600.1108 - Longline catcher processor subsector of the Bering Sea and Aleutian Islands (BSAI) non-pollock...

Code of Federal Regulations, 2014 CFR

2014-10-01

... of the ex-vessel production value of all post-reduction Longline Subsector landings, the fee will be... percent of the ex-vessel Pacific cod revenues, a standardized additional fee will be assessed. The... revenue records and NMFS conversion factors for pollock, arrowtooth flounder, Greenland turbot, skate...

50 CFR 600.1108 - Longline catcher processor subsector of the Bering Sea and Aleutian Islands (BSAI) non-pollock...

Code of Federal Regulations, 2012 CFR

2012-10-01

... of the ex-vessel production value of all post-reduction Longline Subsector landings, the fee will be... percent of the ex-vessel Pacific cod revenues, a standardized additional fee will be assessed. The... revenue records and NMFS conversion factors for pollock, arrowtooth flounder, Greenland turbot, skate...

50 CFR 600.1108 - Longline catcher processor subsector of the Bering Sea and Aleutian Islands (BSAI) non-pollock...

Code of Federal Regulations, 2013 CFR

2013-10-01

... of the ex-vessel production value of all post-reduction Longline Subsector landings, the fee will be... percent of the ex-vessel Pacific cod revenues, a standardized additional fee will be assessed. The... revenue records and NMFS conversion factors for pollock, arrowtooth flounder, Greenland turbot, skate...

RNA-seq analysis of early enteromyxosis in turbot (Scophthalmus maximus): new insights into parasite invasion and immune evasion strategies.

PubMed

Ronza, Paolo; Robledo, Diego; Bermúdez, Roberto; Losada, Ana Paula; Pardo, Belén G; Sitjà-Bobadilla, Ariadna; Quiroga, María Isabel; Martínez, Paulino

2016-07-01

Enteromyxum scophthalmi, an intestinal myxozoan parasite, is the causative agent of a threatening disease for turbot (Scophthalmus maximus, L.) aquaculture. The colonisation of the digestive tract by this parasite leads to a cachectic syndrome associated with high morbidity and mortality rates. This myxosporidiosis has a long pre-patent period and the first detectable clinical and histopathological changes are subtle. The pathogenic mechanisms acting in the early stages of infection are still far from being fully understood. Further information on the host-parasite interaction is needed to assist in finding efficient preventive and therapeutic measures. Here, a RNA-seq-based transcriptome analysis of head kidney, spleen and pyloric caeca from experimentally-infected and control turbot was performed. Only infected fish with early signs of infection, determined by histopathology and immunohistochemical detection of E. scophthalmi, were selected. The RNA-seq analysis revealed, as expected, less intense transcriptomic changes than those previously found during later stages of the disease. Several genes involved in IFN-related pathways were up-regulated in the three organs, suggesting that the IFN-mediated immune response plays a main role in this phase of the disease. Interestingly, an opposite expression pattern had been found in a previous study on severely infected turbot. In addition, possible strategies for immune system evasion were suggested by the down-regulation of different genes encoding complement components and acute phase proteins. At the site of infection (pyloric caeca), modulation of genes related to different structural proteins was detected and the expression profile indicated the inhibition of cell proliferation and differentiation. These transcriptomic changes provide indications regarding the mechanisms of parasite attachment to and invasion of the host. The current results contribute to a better knowledge of the events that characterise the early

Development and characterization of a new marine fish cell line from turbot (Scophthalmus maximus).

PubMed

Wang, N; Wang, X L; Sha, Z X; Tian, Y S; Chen, S L

2010-12-01

A new marine fish cell line, TK, derived from turbot (Scophthalmus maximus) kidney, was established by the method of trypsin digestion and subcultured for more than 50 passages over a period of 300 days. The TK cells were maintained in Minimum Essential Medium Eagle (MEM) supplemented with HEPES, antibiotics, fetal bovine serum (FBS), 2-Mercaptoethanol (2-Me), and basic fibroblast growth factor (bFGF). The suitable growth temperature for TK cells was 24°C, and microscopically, TK cells were composed of fibroblast-like cells. Chromosome analysis revealed that the TK cell line has a normal diploid karyotype with 2n=44. Two fish viruses LCDV-C (lymphocystis disease virus from China) and TRBIV (turbot reddish body iridovirus) were used to determine the virus susceptibility of TK cell line. The TK cell line was found to be susceptible to TRBIV, and the infection was confirmed by cytopathic effect (CPE) and transmission electron microscopy, which detected the viral particles in the cytoplasm of virus-infected cells. Finally, significant green fluorescent signals were observed when the TK cells were transfected with pEGFP-N3 vector, indicating its potential utility for fish virus study and genetic manipulation.

Occupational asthma caused by turbot allergy in 3 fish-farm workers.

PubMed

Pérez Carral, C; Martín-Lázaro, J; Ledesma, A; de la Torre, F

2010-01-01

We report 3 patients (26, 31, and 33 years) who worked at the same fish farm for several years. They experienced symptoms of rhinoconjunctivitis and bronchial asthma while classifying fish by size. Their asthma gradually worsened to the extent that it became persistent and required daily medication with inhaled corticosteroids and bronchodilators. Symptoms improved during weekends and holidays. All 3 patients could eat turbot. Our study showed that the patients were allergic and that sensitization was probably by inhalation. The allergens were parvalbumin in 1 case and a different allergen in the remaining 2 patients.

Spatio-temporal Analysis of the Genetic Diversity of Arctic Rabies Viruses and Their Reservoir Hosts in Greenland

PubMed Central

Hanke, Dennis; Freuling, Conrad M.; Fischer, Susanne; Hueffer, Karsten; Hundertmark, Kris; Nadin-Davis, Susan; Marston, Denise; Fooks, Anthony R.; Bøtner, Anette; Mettenleiter, Thomas C.; Beer, Martin; Rasmussen, Thomas B.; Müller, Thomas F.; Höper, Dirk

2016-01-01

There has been limited knowledge on spatio-temporal epidemiology of zoonotic arctic fox rabies among countries bordering the Arctic, in particular Greenland. Previous molecular epidemiological studies have suggested the occurrence of one particular arctic rabies virus (RABV) lineage (arctic-3), but have been limited by a low number of available samples preventing in-depth high resolution phylogenetic analysis of RABVs at that time. However, an improved knowledge of the evolution, at a molecular level, of the circulating RABVs and a better understanding of the historical perspective of the disease in Greenland is necessary for better direct control measures on the island. These issues have been addressed by investigating the spatio-temporal genetic diversity of arctic RABVs and their reservoir host, the arctic fox, in Greenland using both full and partial genome sequences. Using a unique set of 79 arctic RABV full genome sequences from Greenland, Canada, USA (Alaska) and Russia obtained between 1977 and 2014, a description of the historic context in relation to the genetic diversity of currently circulating RABV in Greenland and neighboring Canadian Northern territories has been provided. The phylogenetic analysis confirmed delineation into four major arctic RABV lineages (arctic 1–4) with viruses from Greenland exclusively grouping into the circumpolar arctic-3 lineage. High resolution analysis enabled distinction of seven geographically distinct subclades (3.I – 3.VII) with two subclades containing viruses from both Greenland and Canada. By combining analysis of full length RABV genome sequences and host derived sequences encoding mitochondrial proteins obtained simultaneously from brain tissues of 49 arctic foxes, the interaction of viruses and their hosts was explored in detail. Such an approach can serve as a blueprint for analysis of infectious disease dynamics and virus-host interdependencies. The results showed a fine-scale spatial population structure

Spatio-temporal Analysis of the Genetic Diversity of Arctic Rabies Viruses and Their Reservoir Hosts in Greenland.

PubMed

Hanke, Dennis; Freuling, Conrad M; Fischer, Susanne; Hueffer, Karsten; Hundertmark, Kris; Nadin-Davis, Susan; Marston, Denise; Fooks, Anthony R; Bøtner, Anette; Mettenleiter, Thomas C; Beer, Martin; Rasmussen, Thomas B; Müller, Thomas F; Höper, Dirk

2016-07-01

There has been limited knowledge on spatio-temporal epidemiology of zoonotic arctic fox rabies among countries bordering the Arctic, in particular Greenland. Previous molecular epidemiological studies have suggested the occurrence of one particular arctic rabies virus (RABV) lineage (arctic-3), but have been limited by a low number of available samples preventing in-depth high resolution phylogenetic analysis of RABVs at that time. However, an improved knowledge of the evolution, at a molecular level, of the circulating RABVs and a better understanding of the historical perspective of the disease in Greenland is necessary for better direct control measures on the island. These issues have been addressed by investigating the spatio-temporal genetic diversity of arctic RABVs and their reservoir host, the arctic fox, in Greenland using both full and partial genome sequences. Using a unique set of 79 arctic RABV full genome sequences from Greenland, Canada, USA (Alaska) and Russia obtained between 1977 and 2014, a description of the historic context in relation to the genetic diversity of currently circulating RABV in Greenland and neighboring Canadian Northern territories has been provided. The phylogenetic analysis confirmed delineation into four major arctic RABV lineages (arctic 1-4) with viruses from Greenland exclusively grouping into the circumpolar arctic-3 lineage. High resolution analysis enabled distinction of seven geographically distinct subclades (3.I - 3.VII) with two subclades containing viruses from both Greenland and Canada. By combining analysis of full length RABV genome sequences and host derived sequences encoding mitochondrial proteins obtained simultaneously from brain tissues of 49 arctic foxes, the interaction of viruses and their hosts was explored in detail. Such an approach can serve as a blueprint for analysis of infectious disease dynamics and virus-host interdependencies. The results showed a fine-scale spatial population structure in

Self-Sufficiency in Northern Justice Issues. Proceedings of the Northern Justice Society Meeting (5th, Sitka, Alaska, April 1991).

ERIC Educational Resources Information Center

Griffiths, Curt Taylor, Ed.

As indigenous peoples in the Arctic move closer to sovereignty, self-sufficiency in the realm of criminal justice assumes paramount importance. This book outlines initiatives and strategies to improve the delivery of justice services to aboriginal peoples in Canada, Alaska, and Greenland. Topics include: social and spiritual causes of alcoholism…

Nuuk, Greenland

NASA Image and Video Library

2008-05-23

Nuuk or Gadthab is the capital and largest city of Greenland. It is located at the mouth of the Nuup Kangerlua inlet on the west coast of Greenland. This image was acquired August 2, 2004 by NASA Terra spacecraft.

Egg production of turbot, Scophthalmus maximus, in the Baltic Sea

NASA Astrophysics Data System (ADS)

Nissling, Anders; Florin, Ann-Britt; Thorsen, Anders; Bergström, Ulf

2013-11-01

In the brackish water Baltic Sea turbot spawn at ~ 6-9 psu along the coast and on offshore banks in ICES SD 24-29, with salinity influencing the reproductive success. The potential fecundity (the stock of vitellogenic oocytes in the pre-spawning ovary), egg size (diameter and dry weight of artificially fertilized 1-day-old eggs) and gonad dry weight were assessed for fish sampled in SD 25 and SD 28. Multiple regression analysis identified somatic weight, or total length in combination with Fulton's condition factor, as main predictors of fecundity and gonad dry weight with stage of maturity (oocyte packing density or leading cohort) as an additional predictor. For egg size, somatic weight was identified as main predictor while otolith weight (proxy for age) was an additional predictor. Univariate analysis using GLM revealed significantly higher fecundity and gonad dry weight for turbot from SD 28 (3378-3474 oocytes/g somatic weight) compared to those from SD 25 (2343 oocytes/g somatic weight), with no difference in egg size (1.05 ± 0.03 mm diameter and 46.8 ± 6.5 μg dry weight; mean ± sd). The difference in egg production matched egg survival probabilities in relation to salinity conditions suggesting selection for higher fecundity as a consequence of poorer reproductive success at lower salinities. This supports the hypothesis of higher size-specific fecundity towards the limit of the distribution of a species as an adaptation to harsher environmental conditions and lower offspring survival probabilities. Within SD 28 comparisons were made between two major fishing areas targeting spawning aggregations and a marine protected area without fishing. The outcome was inconclusive and is discussed with respect to potential fishery induced effects, effects of the salinity gradient, effects of specific year-classes, and effects of maturation status of sampled fish.

Effects of dietary stachyose on growth performance, digestive enzyme activities and intestinal morphology of juvenile turbot ( Scophthalmus maximus L)

NASA Astrophysics Data System (ADS)

Hu, Haibin; Zhang, Yanjiao; Mai, Kangsen; Ai, Qinghui; Xu, Wei; Zhang, Wenbing; Li, Yanxian; Liu, Jintao

2015-10-01

A 12-week feeding trial was conducted to evaluate the effects of dietary stachyose on the growth performance, digestive enzymes activities and intestinal structures of juvenile turbot ( Scophthalmus maximus L). Five isonitrogenous (49.58% crude protein) and isolipidic (10.50% crude lipid) diets were formulated to contain 0 (Control), 0.625% (S-0.625), 1.25% (S-1.25), 2.5% (S-2.5) and 5% (S-5) stachyose, respectively. With the increase of stachyose level, the growth performance and feed utilization of turbot, such as the specific growth rate, final mean body weight, weight gain rate and feed efficiency, increased significantly ( P< 0.05) and then stabilized. The feed intake of fish fed S-5 was significantly higher ( P< 0.05) than that of fish in other groups. The activities of trypsin, intestinal caseinolytic, stomach and intestinal amylase were significantly influenced by stachyose ( P<0.05). The highest values of trypsin and intestinal caseinolytic activities were observed in group S-1.25, while the highest activity of stomach amylase and the lowest activity of intestine amylase were observed in group S-5. No lesion or damage was found on the distal intestine structures of fish from all treatments, while the height of simple folds in the distal intestine was significantly increased ( P< 0.05) when 1.25% or 2.5% stachyose was added in the diets. These results indicated that moderate level of stachyose (1.25%) improves the growth performance, feed utilization, digestive enzyme activities and the distal intestine structures of juvenile turbot.

Effects of dietary carbohydrate-to-lipid ratio on the growth performance and feed utilization of juvenile turbot ( Scophthalmus maximus)

NASA Astrophysics Data System (ADS)

Miao, Shuyan; Nie, Qin; Miao, Huijun; Zhang, Wenbing; Mai, Kangsen

2016-08-01

A 9-week feeding trial was conducted to investigate the effects of dietary carbohydrate to lipid ratio (CHO:LIP) on the growth performance and feed utilization of juvenile turbot Scophthalmus maximus (initial body weight 8.75 g ± 0.04 g). Four isonitrogenous and isoenergetic low protein level (39%) diets were formulated with increasing ratios of dietary carbohydrate to lipid (2:18, 6:18, 18:12 and 28:6). A high protein level (50%) diet with the 2:12 ratio of carbohydrate to lipid was used as the control. Results showed that the survival rate, contents of moisture, crude protein and ash in muscle were not significantly affected by dietary treatments. With the dietary CHO:LIP ratio increased from 2:18 to 18:12, weight gain rate significantly increased ( P < 0.05). Higher dietary CHO:LIP ratio (28:6) resulted in the significantly decreased weight gain rate ( P < 0.05). Meanwhile, this treatment also resulted in the highest daily feed intake and liver glycogen content, as well as the lowest feed efficiency ( P < 0.05). Muscle glycogen content in fish fed the diet with 2:12 or 2:18 CHO:LIP ratio was significantly lower than those fed with the other three diets ( P < 0.05). The present results confirmed that the juvenile turbot can utilize carbohydrate. Furthermore, the appropriate ratio of dietary carbohydrate to lipid was important to the growth and feed utilization of turbot. The proper CHO:LIP ratio based on the growth performance in the present study was determined to be 18:12 when the dietary protein level was 39%.

Protective effect of glutamine and arginine against soybean meal-induced enteritis in the juvenile turbot (Scophthalmus maximus).

PubMed

Gu, Min; Bai, Nan; Xu, Bingying; Xu, Xiaojie; Jia, Qian; Zhang, Zhiyu

2017-11-01

Soybean meal can induce enteritis in the distal intestine (DI) and decrease the immunity of several cultured fish species, including turbot Scophthalmus maximus. Glutamine and arginine supplementation have been used to improve immunity and intestinal morphology in fish. This study was conducted to investigate the effects of these two amino acids on the immunity and intestinal health of turbot suffering from soybean meal-induced enteritis. Turbots (initial weight 7.6 g) were fed one of three isonitrogenous and isolipidic diets for 8 weeks: SBM (control diet), with 40% soybean meal; GLN, SBM diet plus 1.5% glutamine; ARG, the SBM diet plus 1.5% arginine. Symptoms that are typical of soybean meal-induced enteritis, including swelling of the lamina propria and subepithelial mucosa and a strong infiltration of various inflammatory cells was observed in fish that fed the SBM diet. Glutamine and arginine supplementation significantly increased (1) the weight gain and feed efficiency ratio; (2) the height and vacuolization of villi and the integrity of microvilli in DI; (3) serum lysozyme activity, and the concentrations of C3, C4, and IgM. These two amino acids also significantly decreased the infiltration of leucocytes in the lamina propria and submucosa and the expression of inflammatory cytokines including il-8, tnf-α, and tgf-β. For the mucosal microbiota, arginine supplementation significantly increased microbiota community richness and diversity, and glutamine supplementation significantly increased the relative abundance of Lactobacillus and Bacillus. These results indicate that dietary glutamine and arginine improved the growth performance, feed utilization, and distal intestinal morphology, activated the innate and adaptive immune systems, changed the intestinal mucosal microbiota community, and relieved SBMIE possibly by suppression of the inflammation response. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of temperature, pH and NaCl on protease activity in digestive tract of young turbot, Scophthalmus maximus

NASA Astrophysics Data System (ADS)

Chen, Muyan; Zhang, Xiumei; Gao, Tianxiang; Chen, Chao

2006-09-01

The protease activity in digestive tract of young turbot Scophthalmus maximum was studied, and the optimal pH, temperature and NaCl concentration were determined for different portions of the fish's internal organs. The optimal activity in the fish's stomach was at pH of 2.2, while that in the intestinal extracts was within the alkaline range from 9.5 to 10.0. In hepatopancreas, the optimal pH was in low alkalinity at 8.5. The optimal reaction temperature was above 40°C in stomach, intestine and hepatopancreas. With increasing temperature, the pH value increased in stomach, while in the intestine, an opposite tendency was observed due to combined effect of pH and temperature. NaCl concentration showed inhibitory impact on protein digestion in hepatopancreas. The main protease for protein digestion in turbot seemed to be pepsin. Moreover, the maximum protease activity in different segments of intestine existed in the hindgut.

Telemedicine in Greenland: Citizens' Perspectives.

PubMed

Nielsen, Lasse O; Krebs, Hans J; Albert, Nancy M; Anderson, Nick; Catz, Sheryl; Hale, Timothy M; Hansen, John; Hounsgaard, Lise; Kim, Tae Youn; Lindeman, David; Spindler, Helle; Marcin, James P; Nesbitt, Thomas; Young, Heather M; Dinesen, Birthe

2017-05-01

Telemedicine may have the possibility to provide better access to healthcare delivery for the citizens. Telemedicine in arctic remote areas must be tailored according to the needs of the local population. Therefore, we need more knowledge about their needs and their view of telemedicine. The aim of this study has been to explore how citizens living in the Greenlandic settlements experience the possibilities and challenges of telemedicine when receiving healthcare delivery in everyday life. Case study design was chosen as the overall research design. Qualitative interviews (n = 14) were performed and participant observations (n = 80 h) carried out in the local healthcare center in the settlements and towns. A logbook was kept and updated each day during the field research in Greenland. Observations were made of activities in the settlements. Data collected on citizens' views about the possibilities of using telemedicine in Greenland revealed the following findings: Greenlandic citizens are positive toward telemedicine, and telemedicine can help facilitate improved access to healthcare for residents in these Greenlandic settlements. Regarding challenges in using telemedicine in Greenland, the geographical and cultural context hinders accessibility to the Greenlandic healthcare system, and telemedicine equipment is not sufficiently mobile. Greenlandic citizens are positive toward telemedicine and regard telemedicine as a facilitator for improved access for healthcare in the Greenlandic settlements. We have identified challenges, such as geographical and cultural context, that hinder accessibility to the Greenlandic healthcare system.

Design and methods in a survey of living conditions in the Arctic - the SLiCA study.

PubMed

Eliassen, Bent-Martin; Melhus, Marita; Kruse, Jack; Poppel, Birger; Broderstad, Ann Ragnhild

2012-03-19

The main objective of this study is to describe the methods and design of the survey of living conditions in the Arctic (SLiCA), relevant participation rates and the distribution of participants, as applicable to the survey data in Alaska, Greenland and Norway. This article briefly addresses possible selection bias in the data and also the ways to tackle it in future studies. Population-based cross-sectional survey. Indigenous individuals aged 16 years and older, living in Greenland, Alaska and in traditional settlement areas in Norway, were invited to participate. Random sampling methods were applied in Alaska and Greenland, while non-probability sampling methods were applied in Norway. Data were collected in 3 periods: in Alaska, from January 2002 to February 2003; in Greenland, from December 2003 to August 2006; and in Norway, in 2003 and from June 2006 to June 2008. The principal method in SLiCA was standardised face-to-face interviews using a questionnaire. A total of 663, 1,197 and 445 individuals were interviewed in Alaska, Greenland and Norway, respectively. Very high overall participation rates of 83% were obtained in Greenland and Alaska, while a more conventional rate of 57% was achieved in Norway. A predominance of female respondents was obtained in Alaska. Overall, the Sami cohort is older than the cohorts from Greenland and Alaska. Preliminary assessments suggest that selection bias in the Sami sample is plausible but not a major threat. Few or no threats to validity are detected in the data from Alaska and Greenland. Despite different sampling and recruitment methods, and sociocultural differences, a unique database has been generated, which shall be used to explore relationships between health and other living conditions variables.

Ameliorative effect of vitamin E on hepatic oxidative stress and hypoimmunity induced by high-fat diet in turbot (Scophthalmus maximus).

PubMed

Jia, Yudong; Jing, Qiqi; Niu, Huaxin; Huang, Bin

2017-08-01

This study was conducted to examine the effects of vitamin E on growth performance, oxidative stress and non-specific immunity of turbot (Scophthalmus maximus) fed with high-fat diet. Results showed that high-fat diet significantly increased hepatosomatic index, viscerosomatic index, hepatic malondialdehyde level and decreased catalase and superoxide dismutase activities, whereas final weight, specific growth rate and survival rate remained unchanged. Meanwhile, nitro blue tetrazolium positive leucocytes of head kidney, respiratory burst activity in head-kidney macrophage, phagocytic index and serum lysozyme activity were significantly reduced after feeding with high-fat diet. Furthermore, fish fed with high-fat diet promoted higher expression of heat shock protein (hsp70, hsp90), and inhibited expression of complement component 3 (c3) in the liver and tumor necrosis factor-α (tnf-α), interleukine 1β (il-1β), toll like receptor 22 (tlr-22) in the spleen and head-kidney, respectively. However, simultaneous supplementation with 480 mg kg -1 vitamin E protected turbot against high-fat diet-induced hepatic oxidative stress, hypoimmunity through attenuating lipid peroxidation, renewing antioxidant enzymes activities and nonspecific immune responses, and modulating the expression of stress protein (hsp70, hsp90) and immune-related genes (c3, tnf-α, il-1β, tlr-22). In conclusion, the obtained results indicate the vitamin E as a wildly used functional feed additive contributes potentially to alleviate high-fat diet-induced hepatic oxidative stress and hypoimmunity, maintain the health, and improve the broodstock management for turbot. Copyright © 2017 Elsevier Ltd. All rights reserved.

Brief communication: Getting Greenland's glaciers right - a new data set of all official Greenlandic glacier names

NASA Astrophysics Data System (ADS)

Bjørk, A. A.; Kruse, L. M.; Michaelsen, P. B.

2015-12-01

Place names in Greenland can be difficult to get right, as they are a mix of Greenlandic, Danish, and other foreign languages. In addition, orthographies have changed over time. With this new data set, we give the researcher working with Greenlandic glaciers the proper tool to find the correct name for glaciers and ice caps in Greenland and to locate glaciers described in the historic literature with the old Greenlandic orthography. The data set contains information on the names of 733 glaciers, 285 originating from the Greenland Ice Sheet (GrIS) and 448 from local glaciers and ice caps (LGICs).

Greenland to gather more exploration data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1991-01-28

Danish authorities are taking steps to make more exploration data available on Greenland in advance of a possible West Greenland shelf licensing round in 1993. Seismic data acquisition and other studies continue toward more fully evaluating Greenland's oil and gas potential. Geological Survey of Greenland (GGU), Copenhagen, Denmark, is processing 2,041 line miles of reflection seismic data shot on the West Greenland shelf in August and September of 1990. Sixty-fold stacks and migrations will be obtained. Total field magnetic data were also recorded during the survey, known as project Syd Vest Seis. Early work is under way to kick offmore » the multicompany Kanumas seismic acquisition project, proposed in 1986, during 1991. Meanwhile, the Mineral Resources Administration for Greenland (MRA), Copenhagen, the Danish and Greenland governments aim to sweeten Greenland's exploration regulations prior to making areas available.« less

East Asian origin of central Greenland last glacial dust: just one possible scenario?

NASA Astrophysics Data System (ADS)

Újvári, Gábor; Stevens, Thomas; Svensson, Anders; Klötzli, Urs Stephan; Manning, Christina; Németh, Tibor; Kovács, János

2016-04-01

Dust in Greenland ice cores is used to reconstruct the activity of dust emitting regions and atmospheric circulation for the last glacial period. However, the source dust material to Greenland over this period is the subject of considerable uncertainty. Here we use new clay mineral and Sr-Nd isotopic data from eleven loess samples collected around the Northern Hemisphere and compare the 87Sr/86Sr and 143Nd/144Nd isotopic signatures of fine (<10 μm) separates to existing Greenland ice core dust data (GISP2, GRIP; [1]; [2]). Smectite contents and kaolinite/chlorite (K/C) ratios allow exclusion of continental US dust emitting regions as potential sources, because of the very high (>3.6) K/C ratios and extremely high (>~70%) smectite contents. At the same time, Sr-Nd isotopic compositions demonstrate that ice core dust isotopic compositions can be explained by East Asian (Chinese loess) and/or Central/East Central European dust contributions. Central/East Central European loess Sr-Nd isotopic compositions overlap most with ice core dust, while the Sr isotopic signature of Chinese loess is slightly more radiogenic. Nevertheless, an admixture of 90‒10 % from Chinese loess and circum-Pacific volcanic material would also account for the Sr‒Nd isotopic ratios of central Greenland LGM dust. At the same time, sourcing of ice core dust from Alaska, continental US and NE Siberia seems less likely based on Sr and Nd isotopic signatures. The data demonstrate that currently no unique source discrimination for Greenland dust is possible using both published and our new data [3]. Thus, there is a need to identify more diagnostic tracers. Based on initial Hf isotope analyses of fine separates of three loess samples (continental US, Central Europe, China), an apparent dependence of Hf isotopic signatures on the relative proportions of radiogenic clay minerals (primarily illite) was found, as these fine dust fractions are apparently zircon-free. The observed difference between

Hepatic gene transcription profiles in turbot (Scophthalmus maximus) experimentally exposed to heavy fuel oil nº 6 and to styrene.

PubMed

Diaz de Cerio, Oihane; Bilbao, Eider; Ruiz, Pamela; Pardo, Belén G; Martínez, Paulino; Cajaraville, Miren P; Cancio, Ibon

2017-02-01

Oil and chemical spills in the marine environment, although sporadic, are highly dangerous to biota inhabiting coastal and estuarine areas. Effects of spilled compounds in exposed organisms occur at different biological organization levels: from molecular, cellular or tissue levels to the physiological one. The present study aims to determine the specific hepatic gene transcription profiles observed in turbot juveniles under exposure to fuel oil n °6 and styrene vs controls using an immune enriched turbot (Scophthalmus maximus) oligo-microarray containing 2716 specific gene probes. After 3 days of exposure, fuel oil specifically induced aryl hydrocarbon receptor mediated transcriptional response through up-regulation of genes, such as ahrr and cyp1a1. More gene transcripts were regulated after 14 days of exposure involved in ribosomal biosynthesis, immune modulation, and oxidative response among the most significantly regulated functional pathways. On the contrary, gene transcription alterations caused by styrene did not highlight any significantly regulated molecular or metabolic pathway. This was also previously reported at cell and tissue level where no apparent responses were distinguishable. For the fuel oil experiment, obtained specific gene profiles could be related to changes in cell-tissue organization in the same individuals, such as increased hepatocyte vacuolization, decrease in melano-macrophage centers and the regulation of leukocyte numbers. In conclusion, the mode of action reflected by gene transcription profiles analyzed hereby in turbot livers could be linked with the responses previously reported at higher biological organization levels. Molecular alterations described hereby could be preceding observed alterations at cell and tissue levels. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of reproductive endocrine status in hornyhead turbot sampled from Southern California's urbanized coastal environments.

PubMed

Reyes, Jesus A; Vidal-Dorsch, Doris E; Schlenk, Daniel; Bay, Steven M; Armstrong, Jeffrey L; Gully, Joseph R; Cash, Curtis; Baker, Michael; Stebbins, Timothy D; Hardiman, Gary; Kelley, Kevin M

2012-12-01

As part of a regionwide collaboration to determine the occurrence of contaminants and biological effects in coastal ecosystems offshore of urban southern California, the present study characterized the reproductive endocrinology of an indigenous flatfish, the hornyhead turbot (Pleuronichthys verticalis), and compared groups sampled from different study sites representing varying degrees of pollution to screen for potential endocrine disruptive effects. Turbot were sampled from locations near the coastal discharge sites of four large municipal wastewater treatment plants (WWTPs) located between Los Angeles and San Diego, California, USA, and were compared with fish sampled from three far-field reference locations in the region. Despite environmental presence of both legacy contaminants and contaminants of emerging concern and evidence for fish exposure to several classes of contaminants, both males and females generally exhibited coordinated seasonal reproductive cycles at all study sites. Patterns observed included peaks in sex steroids (17β-estradiol, testosterone, 11-ketotestosterone) in the spring and low levels in the fall, changes corresponding to similarly timed gonadal changes and plasma vitellogenin concentrations in females. Comparisons between fish captured at the different study sites demonstrated some regional differences in plasma levels of estrogens and androgens, indicative of location-associated effects on the endocrine system. The observed differences, however, could not be linked to the ocean discharge locations of four of the largest WWTPs in the world. Copyright © 2012 SETAC.

Immunohistochemical study of inducible nitric oxide synthase and tumour necrosis factor alpha response in turbot (Scophthalmus maximus) experimentally infected with Aeromonas salmonicida subsp. salmonicida.

PubMed

Coscelli, Germán; Bermúdez, Roberto; Ronza, Paolo; Losada, Ana Paula; Quiroga, María Isabel

2016-09-01

Aeromonas salmonicida subsp. salmonicida represents one of the major threats in aquaculture, especially in salmonid fish and turbot farming. In order to fight bacterial infections, fish have an immune system composed by innate and specific cellular and humoral elements analogous to those present in mammals. However, innate immunity plays a primordial role against bacterial infections in teleost fish. Among these non-specific mechanisms, the production of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) pathway and the tumour necrosis factor-alpha (TNFα) produced by mononuclear phagocytes, are two of the main immune effectors to eliminate bacterial pathogens. In this study, the distribution and kinetic of iNOS and TNFα-producing cells of kidney and spleen of turbot experimentally inoculated with A. salmonicida was assessed by immunohistochemistry. In control and challenged fish, individual iNOS(+) and TNFα(+) cells, showing a similar pattern of distribution, were detected. In challenged fish, the number of immunoreactive cells was significantly increased in the evaluated organs, as well as the melanomacrophage centres showed variable positivity for both antigens. These results indicate that A. salmonicida induced an immune response in challenged turbot, which involved the increase of the activity of iNOS and TNFα in the leukocytic population from kidney and spleen. Copyright © 2016 Elsevier Ltd. All rights reserved.

Soya-saponins induce intestinal inflammation and barrier dysfunction in juvenile turbot (Scophthalmus maximus).

PubMed

Gu, Min; Jia, Qian; Zhang, Zhiyu; Bai, Nan; Xu, Xiaojie; Xu, Bingying

2018-06-01

Soybean meal-induced enteritis (SBMIE) is a well-described condition in the distal intestine (DI) of several cultured fish species, but the exact cause is still unclear. The work on Atlantic salmon and zebrafish suggested soya-saponins, as heat-stable anti-nutritional factors in soybean meal, are the major causal agents. However, this conclusion was not supported by the research on some other fish, such as gilthead sea bream and European sea bass. Our previous work proved that soybean could induce SBMIE on turbot and the present work aimed to investigate whether soya-saponins alone could cause SBMIE and the effects of soya-saponins on the intestinal barrier function in juvenile turbot. Turbots with initial weight 11.4 ± 0.02 g were fed one of four fishmeal-based diets containing graded levels of soya-saponins (0, 2.5, 7.5, 15 g kg -1 ) for 8 weeks. At the end of the trial, all fish were weighed and plasma was obtained for diamine oxidase (DAO) activity and d-lactate level analysis and DI was sampled for histological evaluation and quantification of antioxidant parameters and inflammatory marker genes. The activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and intestinal glutathione level were selected to evaluated intestinal antioxidant system. The distal intestinal epithelial cell (IEC) proliferation and apoptosis were investigated by proliferating cell nuclear antigen (PCNA) labelling and TdT-mediated dUTP nick end labeling (TUNEL), respectively. The results showed that soya-saponins caused significantly dose-dependent decrease in the growth performance and nutrient utilization (p < 0.05). Enteritis developed in DI of the fish fed diet containing soya-saponins. Significantly dose-dependent increases in severity of the inflammation concomitant with up-regulated expression of il-1β, il-8, and tnf-α, increased IEC proliferation and apoptosis, and decreases in selected antioxidant parameters were detected (p�

Discharge of debris from ice at the margin of the Greenland ice sheet

USGS Publications Warehouse

Knight, P.G.; Waller, R.I.; Patterson, C.J.; Jones, A.P.; Robinson, Z.P.

2002-01-01

Sediment production at a terrestrial section of the ice-sheet margin in West Greenland is dominated by debris released through the basal ice layer. The debris flux through the basal ice at the margin is estimated to be 12-45 m3 m-1 a-1. This is three orders of magnitude higher than that previously reported for East Antarctica, an order of magnitude higher than sites reported from in Norway, Iceland and Switzerland, but an order of magnitude lower than values previously reported from tidewater glaciers in Alaska and other high-rate environments such as surging glaciers. At our site, only negligible amounts of debris are released through englacial, supraglacial or subglacial sediment transfer. Glacio-fluvial sediment production is highly localized, and long sections of the ice-sheet margin receive no sediment from glaciofluvial sources. These findings differ from those of studies at more temperate glacial settings where glaciofluvial routes are dominant and basal ice contributes only a minor percentage of the debris released at the margin. These data on debris flux through the terrestrial margin of an outlet glacier contribute to our limited knowledge of debris production from the Greenland ice sheet.

Molecular epidemiological study of Arctic rabies virus isolates from Greenland and comparison with isolates from throughout the Arctic and Baltic regions.

PubMed

Mansfield, K L; Racloz, V; McElhinney, L M; Marston, D A; Johnson, N; Rønsholt, L; Christensen, L S; Neuvonen, E; Botvinkin, A D; Rupprecht, C E; Fooks, A R

2006-03-01

We report a molecular epidemiological study of rabies in Arctic countries by comparing a panel of novel Greenland isolates to a larger cohort of viral sequences from both Arctic and Baltic regions. Rabies virus isolates originating from wildlife (Arctic/red foxes, raccoon-dogs and reindeer), from domestic animals (dogs/cats) and from two human cases were investigated. The resulting 400 bp N-gene sequences were compared with isolates representing neighbouring Arctic or Baltic countries from North America, the former Soviet Union and Europe. Phylogenetic analysis demonstrated similarities between sequences from the Arctic and Arctic-like viruses, which were distinct from rabies isolates originating in the Baltic region of Europe, the Steppes in Russia and from North America. The Arctic-like group consist of isolates from India, Pakistan, southeast Siberia and Japan. The Arctic group was differentiated into two lineages, Arctic 1 and Arctic 2, with good bootstrap support. Arctic 1 is mainly comprised of Canadian isolates with a single fox isolate from Maine in the USA. Arctic 2 was further divided into sub-lineages: 2a/2b. Arctic 2a comprises isolates from the Arctic regions of Yakutia in northeast Siberia and Alaska. Arctic 2b isolates represent a biotype, which is dispersed throughout the Arctic region. The broad distribution of rabies in the Arctic regions including Greenland, Canada and Alaska provides evidence for the movement of rabies across borders.

Nature and tourism in Greenland

Treesearch

Berit C. Kaae

2002-01-01

This paper provides a short summary on the development of tourism in Greenland, the cultural context, and the protection of the nature resources on which tourism heavily depends. Existing research projects related to tourism in Greenland and the focus of these projects are briefly summarized. In general, most research in Greenland focuses on natural resources, but...

Facts About Alaska, Alaska Kids' Corner, State of Alaska

Science.gov Websites

Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees State of Alaska Search Home Quick Links Departments Commissioners Employee Whitepages State Government Jobs Federal Jobs Starting a Small Business Living Get a Driver License Get a Hunting

Glaciers of Greenland

USGS Publications Warehouse

Williams, Richard S.; Ferrigno, Jane G.

1995-01-01

Landsat imagery, combined with aerial photography, sketch maps, and diagrams, is used as the basis for a description of the geography, climatology, and glaciology, including mass balance, variation, and hazards, of the Greenland ice sheet and local ice caps and glaciers. The Greenland ice sheet, with an estimated area of 1,736,095+/-100 km2 and volume of 2,600,000 km3, is the second largest glacier on the planet and the largest relict of the Ice Age in the Northern Hemisphere. Greenland also has 48,599+/-100 km2 of local ice caps and other types of glaciers in coastal areas and islands beyond the margin of the ice sheet.

Maternally derived trypsin may have multiple functions in the early development of turbot (Scopthalmus maximus).

PubMed

Chi, Liang; Liu, Qinghua; Xu, Shihong; Xiao, Zhizhong; Ma, Daoyuan; Li, Jun

2015-10-01

Trypsin is an important serine protease that is considered to be involved in digestion of protein in teleost fish. Nevertheless, studies on trypsin/trypsinogen in fish embryos are very limited. In this study, the trypsinogen of turbot (Scophthalmus maximus) (tTG) was identified and the expression patterns and activity of trypsinogen/trypsin were investigated. The results showed that the tTG mRNA was evenly distributed in the oocytes and was also expressed along the yolk periphery in early embryos. At later embryo stages and 1 days after hatching (dph), the tTG mRNA concentrated at the alimentary tract and head. Quantitative expression analysis showed that the tTG transcripts decreased after fertilization until the gastrula stage, then increased with the embryo and larvae development. This result was also confirmed by the specific activity analysis of trypsin and in-situ-hybridization (ISH). All of the results indicated that tTG in early embryo stages was maternally derived and expressed by itself after gastrula stages. Additionally, location of tTG mRNA in embryos and larvae was investigated; we considered that trypsin may have multiple functions during the embryo development process. Based on our results regarding trypsinogen in embryos and early development, we concluded that the trypsin/trypsinogen in turbot embryos was inherited from a maternal source and we suggested that trypsin in early development has multiple functions in the process of development. Copyright © 2015 Elsevier Inc. All rights reserved.

TopoGreenland: crustal structure in central-eastern Greenland along a new refraction profile

NASA Astrophysics Data System (ADS)

Shulgin, Alexey; Thybo, Hans; Field Team TopoGreenland

2013-04-01

We present the seismic structure in the interior of Greenland based on the first measurements by the seismic refraction/wide angle reflection method. Previous seismic surveys have only been carried out offshore and near the coast of Greenland, where the crustal structure is affected by oceanic break-up and may not be representative of the interior of the island. Acquisition of geophysical data in onshore Greenland is logistically complicated by the presence of an up to 3.4 km thick ice sheet, permanently covering most of the land mass. The seismic data was acquired by a team of six people during a two-month long experiment in summer of 2011 on the ice cap in the interior of central-eastern Greenland. The EW-trending profile extends 310 km inland from the approximate edge of the stable ice cap near Scoresby Sund across the center of the ice cap. The planned extension of the profile by use of OBSs and air gun shooting in Scoresbysund Fjord to the east coast of Greenland was unfortunately canceled, because navigation was prevented by ice drift. 350 Reftek Texan receivers recorded high-quality seismic data from 8 equidistant shots along the profile. Explosive charge sizes were 1 ton at the ends and ca. 500 kg along the profile, loaded with about 125 kg at 35-85 m depth in individual boreholes. Two-dimensional velocity model based on tomographic inversion and forward ray tracing modeling shows a decrease of crustal thickness from 47 km below the center of Greenland in the western part to 40 km in the eastern part of the profile. Earlier studies show that crustal thickness further decreases eastward to ca. 30 km below the fjord system, but details of the changes are unknown. Relatively high lower crustal velocities (Vp 6.8 - 7.3) in the western part of the TopoGreenland profile may indicate past collision tectonics or may be related or to the passage of the Iceland mantle plume. The origin of the pronounced circum-Atlantic mountain ranges in Norway and eastern Greenland

Ocean forces Greenland and Greenland forces the ocean: a two-way exchange at Greenland's marine margins

NASA Astrophysics Data System (ADS)

Straneo, F.

2017-12-01

The widespread speed up of Greenland's glaciers, over the last two decades, was unpredicted, revealing major gaps in our understanding of how ice sheets respond to a changing climate. Increased submarine melting at the edge of glaciers has emerged as a key trigger - indicating that glacier/ocean exchanges must be accounted for in ice sheet variability reconstructions and predictions. In parallel, the increasing freshwater discharge into the ocean, associated with Greenland's ice loss, has the potential to impact the North Atlantic's circulation and climate. Thus glacier/ocean exchanges are also relevant to understanding drivers of past and future changes in the North Atlantic Ocean's circulation. Here, I present recent findings from observations collected at the edge of several Greenland glaciers that reveal how melting is caused by intrusions of warm, subtropical waters into the fjords and enhanced by the release of surface melt hundreds of meters below sea level. Similarly, hydrographic and tracer data collected at the glaciers' margins, and within the glacial fjords, reveal how Greenland meltwater are exported in the form of highly diluted glacially modified waters, often subsurface, and temporally lagged with respect to the meltwater release. These findings underline the need for improved representation of ice/ocean exchanges in models in order understand and predict the ice sheet's impact on the ocean and the ocean's impact on the ice sheet.

Ocean forces Greenland and Greenland forces the ocean: a two-way exchange at Greenland's marine margins

NASA Astrophysics Data System (ADS)

Stanley, V.; Schoephoester, P.; Lodge, R. W. D.

2016-12-01

The widespread speed up of Greenland's glaciers, over the last two decades, was unpredicted, revealing major gaps in our understanding of how ice sheets respond to a changing climate. Increased submarine melting at the edge of glaciers has emerged as a key trigger - indicating that glacier/ocean exchanges must be accounted for in ice sheet variability reconstructions and predictions. In parallel, the increasing freshwater discharge into the ocean, associated with Greenland's ice loss, has the potential to impact the North Atlantic's circulation and climate. Thus glacier/ocean exchanges are also relevant to understanding drivers of past and future changes in the North Atlantic Ocean's circulation. Here, I present recent findings from observations collected at the edge of several Greenland glaciers that reveal how melting is caused by intrusions of warm, subtropical waters into the fjords and enhanced by the release of surface melt hundreds of meters below sea level. Similarly, hydrographic and tracer data collected at the glaciers' margins, and within the glacial fjords, reveal how Greenland meltwater are exported in the form of highly diluted glacially modified waters, often subsurface, and temporally lagged with respect to the meltwater release. These findings underline the need for improved representation of ice/ocean exchanges in models in order understand and predict the ice sheet's impact on the ocean and the ocean's impact on the ice sheet.

Drivers of River Water Temperature Space-time Variability in Northeast Greenland

NASA Astrophysics Data System (ADS)

Hannah, D. M.; Docherty, C.; Milner, A.

2015-12-01

Water temperature plays an important role in stream ecosystem functioning; however, water temperature dynamics in high Arctic environments have received relatively little attention. Given that global climate is predicted to change most at high latitudes, it is vital we broaden our knowledge of space-time variability in Arctic river temperature to understand controlling processes and potential consequences of climate change. To address this gap, our research aims: (1) to characterise seasonal and diel patterns of variability over three summer and two winter seasons with contrasting hydrometeorological conditions, (2) to unravel the key drivers influencing thermal regimes and (3) to place these results in the context of other snow/ glacier-melt dominated environments. Fieldwork was undertaken in July-September 2013, 2014 and 2015 close to the Zackenberg Research Station in Northeast Greenland - an area of continuous permafrost with a mean July air temperature of 6 °C. Five streams were chosen that drain different water source contributions (glacier melt, snow melt, groundwater). Data were collected at 30 minute intervals using micro-dataloggers. Air temperature data were collected within 7km by the Greenland Survey. Weather conditions were highly variable between field campaigns, with 2013 experiencing below average, and 2014 and 2015 above average, snowfall. Summer water temperatures appear to be high in comparison to some Arctic streams in Alaska and in Svalbard. Winter snowfall extent decreases stream water temperature; and water temperature increases with atmospheric exposure time (distance from source) - illustrating the intertwined controls of water and heat fluxes. These Greenland streams are most strongly influenced by snowmelt, but groundwater contributions could increase with a changing climate due to increased active layer thickness, which may result in increased river temperature with implications for aquatic biodiversity and ecosystem functioning.

Applications of satellite telemetry to wildlife research and management in Alaska

USGS Publications Warehouse

Fancy, S.G.; Harris, R.B.; Douglas, David C.; Pank, L.F.; Whitten, Kenneth R.; McCabe, Thomas R.; Amstrup, Steven C.; Garner, G.W.

1988-01-01

Since 1984, the Alaska Fish and Wildlife Research Center, in cooperation with the Alaska Department of Fish and Game and several other agencies, has used the Argos Data Collection and Location System to address wildlife research and management problems in Alaska and other parts of North America. The use of satellite telemetry has overcome some of the logistical problems of working in remote areas in an arctic environment, where harsh weather, darkness, worker safety considerations, extensive movements by some species, and high costs of locating study animals often result in small incomplete data sets. As of September 1988, 241 satellite transmitters (PPTs) have been deployed on large mammals, including 109 on polar bears in the Bering, Beaufort and Chukchi seas; 74 on caribou in northern Alaska and northwestern Canada; 22 on brown bears in northern Alaska and Kodiak Island, Alaska; 12 on muskoxen in northeastern Alaska and Greenland; 7 on wolves in northern Alaska; 7 on walrus in the Bering and Chuckchi seas; 4 on mule deer in Idaho; 2 on elk in Wyoming; 2 on moose in southcentral Alaska; and 2 on Dall sheep int the Brooks Range of northern Alaska. The Argos DCLS has provided more than 19,000 and 66,000 locations for polar bears and caribou, respectively, and has been used to document the international ranges of these species and to address specific management questions in a cost-effective manner. The precision of locations provided by the Argos DCLS was examined using transmitters placed on the ground or on buildings and compared to the precision from that prior to deployment, presumably because of the proximity of the antenna to the animal's body. The mean error of locations for PTTs on captive animals was 954 m(+or- 1324 SD; median -553 m; n -330). Sensors for determining ambient temperature, short- and long-term indices of animal activity immersion of transmitters in saltwater, and dive depths, were developed and tested. The long-term activity index indicated

[Rabies in a cat in Greenland].

PubMed

Christensen, Laurids Siig; Jacobsen, Keld; Maersk-Møller, Elisabeth

2008-08-18

We describe the first case of rabies diagnosed in a cat in Greenland. The cat showed aggressive behaviour one month after the visit of a rabid fox on the premises. Rabies is enzootic in Greenland, the arctic fox being the natural host of rabies virus. Cats are imported in increasing numbers to Greenland and the reported case stresses the need for concern in relation to a hitherto unrecognised risk of exposure to rabies virus and stresses the need to comply with the obligatory anti-rabies vaccination regimes for cats in Greenland.

Greenland Ice Sheet Mass Balance

NASA Technical Reports Server (NTRS)

Reeh, N.

1984-01-01

Mass balance equation for glaciers; areal distribution and ice volumes; estimates of actual mass balance; loss by calving of icebergs; hydrological budget for Greenland; and temporal variations of Greenland mass balance are examined.

Oceans Melting Greenland OMG 2017 Media Reel

NASA Image and Video Library

2017-12-05

The Oceans Melting Greenland mission seeks to understand how ocean water is contributing to ice loss in Greenland. In October 2017, mission scientists and crew dropped 240 ocean probes from a C-130 aircraft into the waters around Greenland to measure ocean temperature and salinity. Footage includes aerial shots of Greenland landscapes, interior and exterior shots of the aircraft with crew and scientists at work, and shots from a chase plane showing the probes dropping.

[I.U.D. in Greenland].

PubMed

Berg, O

1971-11-05

In the past few decades, Greenland has experienced a population explosion, due mainly to a significant decrease in death from tuberculosis and an increase in the birthrate. 50% of the population of Greenland is younger than 16 years of age. The condom and diaphragm were the main methods of contraception used in Greenland, but neither was used extensively; in the case of the diaphragm, the lack of privacy in larger families (where contraception is most needed) because of cramped living conditions makes difficult the necessary hygiene which accompanies the use of the diaphragm. A campaign was undertaken to introduce the IUD in Greenland. In the district of Narssaq 152 women, approximately 33% of the women 15-44 years of age, had IUDs inserted over a period of 20 months. 48% of the women were unmarried, 40% were married. 16% of the women were between 15-19 years old, 51% between 20-29. IUDs are preferred over oral contraceptives because of mass media public relations advertising and the social and cultural demand for a nonregimented form of contraception. The birthrate in Greenland dropped from 40 to 30% and in Narssaq from approximately 40 to 20% during the campaign.

Aliphatic hydrocarbon levels in turbot and salmon farmed close to the site of the Aegean Sea oil spill

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alvarez Pineiro, M.E.; Gonzalez-Barros, S.T.C.; Lozano, J.S.

After the Andros Patria oil spill, the most serious oil tanker accident to occur off the coast of Galicia (N.W. Spain) was the running aground and subsequent conflagration of the Aegean Sea supertanker outside the northern Spanish port of La Coruna (December 3rd 1992). Approximately 60,000 tonnes of Brent oil were spilled into the Atlantic Ocean in the cited coastal region. Subsequently, an impropitious combination of a high tide and a change in wind direction caused the resulting slick to rapidly spread into the port. Measures aimed at cleaning up affected areas and evacuating the ca. 11,215 tonnes of oilmore » remaining in the supertanker were immediately implemented. However, within just a few days the resulting contamination had killed some 15000 turbot juveniles and larvae, which are cultivated in fish farms close to the accident site. The environmental impact of major oil spillages has been widely studied. Several scientists have suggested that, in terms of the negative effects on the seawater quality and productive capacity of the affected maritime regions, the magnitudes of the Aegean Sea and Amoco Cadiz accidents are comparable. This paper reports variations over time of aliphatic hydrocarbon levels in turbot and Atlantic salmon sampled from fish farms close to the site of the Aegean Sea oil spill. 6 refs., 2 figs., 1 tab.« less

Greenland Gains Some, Loses More

NASA Image and Video Library

2010-02-19

NASA GRACE mission has become a key source of knowledge about global ice mass changes. Studies of Greenland using GRACE and other data indicate that between 2000 and 2008 the Greenland ice sheet lost as much as 1,500 gigatons of mass.

Alaska Department of Revenue - Alaska Film Office

Science.gov Websites

State Employees Alaska Film Office Alaska Film Office State of Alaska HOME CREDIT PROGRAM PUBLIC REPORTING CPA ECONOMIC DEVELOPMENT CONTACT US State of Alaska > Department of Revenue > Alaska Film Office > Text Size: A+ | A- | A Text Only Effective July 1, 2015, the film production incentive

Responses of conventional and molecular biomarkers in turbot Scophthalmus maximus exposed to heavy fuel oil no. 6 and styrene.

PubMed

Ruiz, Pamela; Ortiz-Zarragoitia, Maren; Orbea, Amaia; Theron, Michael; Le Floch, Stéphane; Cajaraville, Miren P

2012-07-15

Several accidental spills in European coastal areas have resulted in the release of different toxic compounds into the marine environment, such as heavy fuel oil type no. 6 in the "Erika" and "Prestige" oil spills and the highly toxic styrene after the loss of the "Ievoli Sun". There is a clear need to develop tools that might allow assessing the biological impact of these accidental spills on aquatic organisms. The aim of the present study was to determine the short-term effects and recovery after exposure of juvenile fish (Scophthalmus maximus) to heavy fuel oil no. 6 and styrene by using a battery of molecular, cell and tissue level biomarkers. Turbots were exposed to styrene for 7 days and to the diluted soluble fraction of the oil (10%) for 14 days, and then allowed to recover in clean seawater for the same time periods. cyp1a1 transcript was overexpressed in turbots after 3 and 14 days of exposure to heavy fuel oil, whereas ahr transcription was not modulated after heavy fuel oil and styrene exposure. pparα transcription level was significantly up-regulated after 3 days of treatment with styrene. Liver activity of peroxisomal acyl-CoA oxidase (AOX) was significantly induced after 14 days of oil exposure, but it was not affected by styrene. Hepatocyte lysosomal membrane stability (LMS) was significantly reduced after exposure to both treatments, indicating that the tested compounds significantly impaired fish health. Both AOX and LMS values returned to control levels after the recovery period. No differences in gamete development were observed between fuel- or styrene- exposed fish and control fish, and vitellogenin plasma levels were low, suggesting no xenoestrogenic effects of fuel oil or styrene. While styrene did not cause any increase in the prevalence of liver histopathological alterations, prevalence of extensive cell vacuolization increased after exposure to heavy fuel oil for 14 days. In conclusion, the suite of selected biomarkers proved to be

Towards Introducing a Geocoding Information System for Greenland

NASA Astrophysics Data System (ADS)

Siksnans, J.; Pirupshvarre, Hans R.; Lind, M.; Mioc, D.; Anton, F.

2011-08-01

Currently, addressing practices in Greenland do not support geocoding. Addressing points on a map by geographic coordinates is vital for emergency services such as police and ambulance for avoiding ambiguities in finding incident locations (Government of Greenland, 2010) Therefore, it is necessary to investigate the current addressing practices in Greenland. Asiaq (Asiaq, 2011) is a public enterprise of the Government of Greenland which holds three separate databases regards addressing and place references: - list of locality names (towns, villages, farms), - technical base maps (including road center lines not connected with names, and buildings), - the NIN registry (The Land Use Register of Greenland - holds information on the land allotments and buildings in Greenland). The main problem is that these data sets are not interconnected, thus making it impossible to address a point in a map with geographic coordinates in a standardized way. The possible solutions suffer from the fact that Greenland has a scattered habitation pattern and the generalization of the address assignment schema is a difficult task. A schema would be developed according to the characteristics of the settlement pattern, e.g. cities, remote locations and place names. The aim is to propose an ontology for a common postal address system for Greenland. The main part of the research is dedicated to the current system and user requirement engineering. This allowed us to design a conceptual database model which corresponds to the user requirements, and implement a small scale prototype. Furthermore, our research includes resemblance findings in Danish and Greenland's addressing practices, data dictionary for establishing Greenland addressing system's logical model and enhanced entity relationship diagram. This initial prototype of the Greenland addressing system could be used to evaluate and build the full architecture of the addressing information system for Greenland. Using software engineering

Building sustained partnerships in Greenland through shared science

NASA Astrophysics Data System (ADS)

Culler, L. E.; Albert, M. R.; Ayres, M. P.; Grenoble, L. A.; Virginia, R. A.

2013-12-01

Greenland is a hotspot for polar environmental change research due to rapidly changing physical and ecological conditions. Hundreds of international scientists visit the island each year to carry out research on diverse topics ranging from atmospheric chemistry to ice sheet dynamics to Arctic ecology. Despite the strong links between scientific, social, and political issues of rapid environmental change in Greenland, communication with residents of Greenland is often neglected by researchers. Reasons include language barriers, difficulties identifying pathways for communication, balancing research and outreach with limited resources, and limited social and cultural knowledge about Greenland by scientists. Dartmouth College has a legacy of work in the Polar Regions. In recent years, a National Science Foundation (NSF) Integrative Graduate Education and Research Traineeship (IGERT) in Polar Environmental Change funded training for 25 Ph.D. students in the Ecology, Earth Science, and Engineering graduate programs at Dartmouth. An overarching goal of this program is science communication between these disciplines and to diverse audiences, including communicating about rapid environmental change with students, residents, and the government of Greenland. Students and faculty in IGERT have been involved in the process of engaging with and sustaining partnerships in Greenland that support shared cultural and educational experiences. We have done this in three ways. First, a key component of our program has been hosting students from Ilisimatusarfik (the University of Greenland). Since 2009, five Greenlandic students have come to Dartmouth and formed personal connections with Dartmouth students while introducing their Greenlandic culture and language (Kalaallisut). Second, we have used our resources to extend our visits to Greenland, which has allowed time to engage with the community in several ways, including sharing our science via oral and poster presentations at Katuaq

Atuarfitsialak: Greenland's Cultural Compatible Reform

ERIC Educational Resources Information Center

Wyatt, Tasha R.

2012-01-01

In 2002, Greenlandic reform leaders launched a comprehensive, nation-wide reform to create culturally compatible education. Greenland's reform work spans the entire educational system and includes preschool through higher education. To assist their efforts, reform leaders adopted the Standards for Effective Pedagogy developed at the Center for…

Sexual and reproductive health in Greenland: evaluation of implementing sexual peer-to-peer education in Greenland (the SexInuk project).

PubMed

Homøe, Anne-Sophie; Knudsen, Ane-Kersti Skaarup; Nielsen, Sigrid Brisson; Grynnerup, Anna Garcia-Alix

2015-01-01

Background For decades, the rates of sexually transmitted infections (STIs), such as gonorrhoea, chlamydia and syphilis, have increased in Greenland, especially within the young age groups (15-29 years). From 2006 to 2013, the number of abortions has been consistent with approximately 800-900 abortions per year in Greenland, which is nearly as high as the total number of births during the same period. Previous studies in Greenland have reported that knowledge about sexual health is important, both as prevention and as facilitator to stop the increasing rates of STIs. A peer-to-peer education programme about sexual health requires adaption to cultural values and acceptance among the population and government in order to be sustainable. Objective Formative evaluation of a voluntary project (SexInuk), in relation to peer-to-peer education with focus on sexual health. Two workshops were conducted in Nuuk, Greenland, to recruit Greenlandic students. Design Qualitative design with focus group interviews (FGIs) to collect qualitative feedback on feasibility and implementation of the project. Supplemented with a brief questionnaire regarding personal information (gender, age, education) and questions about the educational elements in the SexInuk project. Eight Greenlandic students, who had completed one or two workshops, were enrolled. Results The FGIs showed an overall consensus regarding the need for improving sexual health education in Greenland. The participants requested more voluntary educators, to secure sustainability. The articulation of taboo topics in the Greenlandic society appeared very important. The participants suggested more awareness by promoting the project. Conclusion Cultural values and language directions were important elements in the FGIs. To our knowledge, voluntary work regarding peer-to-peer education and sexual health has not been structurally evaluated in Greenland before. To achieve sustainability, the project needs educators and financial

Sexual and reproductive health in Greenland: evaluation of implementing sexual peer-to-peer education in Greenland (the SexInuk project).

PubMed

Homøe, Anne-Sophie; Knudsen, Ane-Kersti Skaarup; Nielsen, Sigrid Brisson; Grynnerup, Anna Garcia-Alix

2015-01-01

For decades, the rates of sexually transmitted infections (STIs), such as gonorrhoea, chlamydia and syphilis, have increased in Greenland, especially within the young age groups (15-29 years). From 2006 to 2013, the number of abortions has been consistent with approximately 800-900 abortions per year in Greenland, which is nearly as high as the total number of births during the same period. Previous studies in Greenland have reported that knowledge about sexual health is important, both as prevention and as facilitator to stop the increasing rates of STIs. A peer-to-peer education programme about sexual health requires adaption to cultural values and acceptance among the population and government in order to be sustainable. Formative evaluation of a voluntary project (SexInuk), in relation to peer-to-peer education with focus on sexual health. Two workshops were conducted in Nuuk, Greenland, to recruit Greenlandic students. Qualitative design with focus group interviews (FGIs) to collect qualitative feedback on feasibility and implementation of the project. Supplemented with a brief questionnaire regarding personal information (gender, age, education) and questions about the educational elements in the SexInuk project. Eight Greenlandic students, who had completed one or two workshops, were enrolled. The FGIs showed an overall consensus regarding the need for improving sexual health education in Greenland. The participants requested more voluntary educators, to secure sustainability. The articulation of taboo topics in the Greenlandic society appeared very important. The participants suggested more awareness by promoting the project. Cultural values and language directions were important elements in the FGIs. To our knowledge, voluntary work regarding peer-to-peer education and sexual health has not been structurally evaluated in Greenland before. To achieve sustainability, the project needs educators and financial support. Further research is needed to investigate

Results of the Greenland ice sheet model initialisation experiments: ISMIP6 - initMIP-Greenland

NASA Astrophysics Data System (ADS)

Goelzer, Heiko; Nowicki, Sophie; Edwards, Tamsin; Beckley, Matthew

2017-04-01

Ice sheet model initialisation has a large effect on projected future sea-level contributions and gives rise to important uncertainties. The goal of this intercomparison exercise for the continental-scale Greenland ice sheet is therefore to compare, evaluate and improve the initialisation techniques used in the ice sheet modelling community. The initMIP-Greenland project is the first in a series of ice sheet model intercomparison activities within ISMIP6 (Ice Sheet Model Intercomparison Project for CMIP6). The experimental set-up has been designed to allow comparison of the initial present-day state of the Greenland ice sheet between participating models and against observations. Furthermore, the initial states are tested with two schematic forward experiments to evaluate the initialisation in terms of model drift (forward run without any forcing) and response to a large perturbation (prescribed surface mass balance anomaly). We present and discuss results that highlight the wide diversity of data sets, boundary conditions and initialisation techniques used in the community to generate initial states of the Greenland ice sheet.

76 FR 71269 - Fisheries of the Exclusive Economic Zone Off Alaska; Greenland Turbot in the Bering Sea Subarea...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-17

... the Bering Sea Subarea of the Bering Sea and Aleutian Islands Management Area AGENCY: National Marine... Bering Sea subarea of the Bering Sea and Aleutian Islands management area. This action is necessary to... management plan for the Bering Sea and Aleutian Islands management area. DATES: Effective November 14, 2011...

Overseas trip report, CV 990 underflight mission. [Norwegian Sea, Greenland ice sheet, and Alaska

NASA Technical Reports Server (NTRS)

Gloersen, P.; Crawford, J.; Hardis, L.

1980-01-01

The scanning microwave radiometer-7 simulator, the ocean temperature scanner, and an imaging scatterometer/altimeter operating at 14 GHz were carried onboard the NASA CV-990 over open oceans, sea ice, and continental ice sheets to gather surface truth information. Data flights were conducted over the Norwegian Sea to map the ocean polar front south and west of Bear Island and to transect several Nimbus-7 footprints in a rectangular pattern parallel to the northern shoreline of Norway. Additional flights were conducted to obtain correlative data on the cryosphere parameters and characteristics of the Greenland ice sheet, and study the frozen lakes near Barrow. The weather conditions and flight path way points for each of the nineteen flights are presented in tables and maps.

Protein-sparing effect of carbohydrate in diets for juvenile turbot Scophthalmus maximus reared at different salinities

NASA Astrophysics Data System (ADS)

Zeng, Lin; Lei, Jilin; Ai, Chunxiang; Hong, Wanshu; Liu, Bin

2015-01-01

The aim of the present study was to investigate the protein-sparing effect of carbohydrate in diets for juvenile turbot ( Scophthalmus maximus) reared at five salinities (12, 18, 24, 30, and 36). The fish were fed three isocaloric and isolipidic diets for 60 days. The results show that specific growth rate (SGR) and feed conversion efficiency (FCE) were higher in fish reared at salinities of 18 and 36, but lower at 12. Fish fed with diet C25P40 (25% carbohydrate and 40% protein) had lower SGR and FCE values compared with those fed with the C5P52 (5% carbohydrate and 52% protein) and C15P46 (15% carbohydrate and 46% protein) diets; however, there was no statistical difference between diet C5P52 and C15P46. SGR and FCE values were unaffected by diet composition in fish reared at salinity 36. Hepatic lipogenic enzyme activities were higher in fish reared at 18 and 36, but lower at 12, while glucokinase (GK) activity was higher in fish reared at 12, and lower at 18 and 36. Dietary starch enhanced GK activity while depressing lipogenic enzyme activity. However, lipogenic enzyme activity increased with increasing dietary starch in fish reared at 36. It is recommended that salinity should be maintained >12 in the farming of juvenile turbot. In addition, an increase in gelatinized starch from 5% to 15% could spare 6% dietary protein in fish reared at salinities of 18-30, while higher salinity (36) could improve dietary carbohydrate use and enhance the protein-sparing effect, which is linked with the induction of lipogenic capacities.

Results of the Greenland Ice Sheet Model Initialisation Experiments ISMIP6 - initMIP-Greenland

NASA Astrophysics Data System (ADS)

Goelzer, H.; Nowicki, S.; Edwards, T.; Beckley, M.; Abe-Ouchi, A.; Aschwanden, A.; Calov, R.; Gagliardini, O.; Gillet-chaulet, F.; Golledge, N. R.; Gregory, J. M.; Greve, R.; Humbert, A.; Huybrechts, P.; Larour, E. Y.; Lipscomb, W. H.; Le ´h, S.; Lee, V.; Kennedy, J. H.; Pattyn, F.; Payne, A. J.; Rodehacke, C. B.; Rückamp, M.; Saito, F.; Schlegel, N.; Seroussi, H. L.; Shepherd, A.; Sun, S.; Vandewal, R.; Ziemen, F. A.

2016-12-01

Earlier large-scale Greenland ice sheet sea-level projections e.g. those run during ice2sea and SeaRISE initiatives have shown that ice sheet initialisation can have a large effect on the projections and gives rise to important uncertainties. The goal of this intercomparison exercise (initMIP-Greenland) is to compare, evaluate and improve the initialization techniques used in the ice sheet modeling community and to estimate the associated uncertainties. It is the first in a series of ice sheet model intercomparison activities within ISMIP6 (Ice Sheet Model Intercomparison Project for CMIP6). Two experiments for the large-scale Greenland ice sheet have been designed to allow intercomparison between participating models of 1) the initial present-day state of the ice sheet and 2) the response in two schematic forward experiments. The forward experiments serve to evaluate the initialisation in terms of model drift (forward run without any forcing) and response to a large perturbation (prescribed surface mass balance anomaly). We present and discuss final results of the intercomparison and highlight important uncertainties with respect to projections of the Greenland ice sheet sea-level contribution.

Clouds enhance Greenland ice sheet meltwater runoff

PubMed Central

Van Tricht, K.; Lhermitte, S.; Lenaerts, J. T. M.; Gorodetskaya, I. V.; L'Ecuyer, T. S.; Noël, B.; van den Broeke, M. R.; Turner, D. D.; van Lipzig, N. P. M.

2016-01-01

The Greenland ice sheet has become one of the main contributors to global sea level rise, predominantly through increased meltwater runoff. The main drivers of Greenland ice sheet runoff, however, remain poorly understood. Here we show that clouds enhance meltwater runoff by about one-third relative to clear skies, using a unique combination of active satellite observations, climate model data and snow model simulations. This impact results from a cloud radiative effect of 29.5 (±5.2) W m−2. Contrary to conventional wisdom, however, the Greenland ice sheet responds to this energy through a new pathway by which clouds reduce meltwater refreezing as opposed to increasing surface melt directly, thereby accelerating bare-ice exposure and enhancing meltwater runoff. The high sensitivity of the Greenland ice sheet to both ice-only and liquid-bearing clouds highlights the need for accurate cloud representations in climate models, to better predict future contributions of the Greenland ice sheet to global sea level rise. PMID:26756470

Clouds enhance Greenland ice sheet meltwater runoff.

PubMed

Van Tricht, K; Lhermitte, S; Lenaerts, J T M; Gorodetskaya, I V; L'Ecuyer, T S; Noël, B; van den Broeke, M R; Turner, D D; van Lipzig, N P M

2016-01-12

The Greenland ice sheet has become one of the main contributors to global sea level rise, predominantly through increased meltwater runoff. The main drivers of Greenland ice sheet runoff, however, remain poorly understood. Here we show that clouds enhance meltwater runoff by about one-third relative to clear skies, using a unique combination of active satellite observations, climate model data and snow model simulations. This impact results from a cloud radiative effect of 29.5 (±5.2) W m(-2). Contrary to conventional wisdom, however, the Greenland ice sheet responds to this energy through a new pathway by which clouds reduce meltwater refreezing as opposed to increasing surface melt directly, thereby accelerating bare-ice exposure and enhancing meltwater runoff. The high sensitivity of the Greenland ice sheet to both ice-only and liquid-bearing clouds highlights the need for accurate cloud representations in climate models, to better predict future contributions of the Greenland ice sheet to global sea level rise.

21 CFR 102.57 - Greenland turbot (Reinhardtius hippoglossoides).

Code of Federal Regulations, 2010 CFR

2010-04-01

...). 102.57 Section 102.57 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION COMMON OR USUAL NAME FOR NONSTANDARDIZED FOODS Requirements... Pleuronectidae right-eye flounders. The term “halibut” may be associated only with Atlantic halibut (Hippoglossus...

Crustal structure of the Central-Eastern Greenland: results from the TopoGreenland refraction profile

NASA Astrophysics Data System (ADS)

Shulgin, Alexey; Thybo, Hans

2014-05-01

Until present, seismic surveys have only been carried out offshore and near the coasts of Greenland, where the crustal structure is affected by oceanic break-up. We present the deep seismic structure of the crust of the interior of Greenland, based on the new and the only existing so far seismic refraction/wide-angle reflection profile. The seismic data was acquired by a team of six people during a two-month long experiment in summer of 2011 on the ice cap in the interior of central-eastern Greenland. The presence of an up to 3.4 km thick ice sheet, permanently covering most of the land mass, made acquisition of geophysical data logistically complicated. The profile extends 310 km inland in E-W direction from the approximate edge of the stable ice cap near the Scoresby Sund across the center of the ice cap. 350 Reftek Texan receivers recorded high-quality seismic data from 8 equidistant shots along the profile. Explosive charge sizes were 1 ton at the ends and ca. 500 kg along the profile, loaded with about 125 kg at 35-85 m depth in individual boreholes. Given that the data acquisition was affected by the thick ice sheet, we questioned the quality of seismic records in such experiment setup. We have developed an automatic routine to check the amplitudes and spectra of the selected seismic phases and to check the differences/challenges in making seismic experiments on ice and the effects of ice on data interpretation. Using tomographic inversion and forward ray tracing modelling we have obtained the two-dimensional velocity model down to a 50 km depth. The model shows a decrease of crustal thickness from 47 km below the centre of Greenland in the western part of the profile to 40 km in its eastern part. Relatively high lower crustal velocities (Vp 6.8 - 7.3 km/s) in the western part of the TopoGreenland profile may result from past collision tectonics or, alternatively, may be related to the speculated passage of the Iceland mantle plume. Comparison of our results

Modelling Greenland icebergs

NASA Astrophysics Data System (ADS)

Marson, Juliana M.; Myers, Paul G.; Hu, Xianmin

2017-04-01

The Atlantic Meridional Overturning Circulation (AMOC) is well known for carrying heat from low to high latitudes, moderating local temperatures. Numerical studies have examined the AMOC's variability under the influence of freshwater input to subduction and deep convections sites. However, an important source of freshwater has often been overlooked or misrepresented: icebergs. While liquid runoff decreases the ocean salinity near the coast, icebergs are a gradual and remote source of freshwater - a difference that affects sea ice cover, temperature, and salinity distribution in ocean models. Icebergs originated from the Greenland ice sheet, in particular, can affect the subduction process in Labrador Sea by decreasing surface water density. Our study aims to evaluate the distribution of icebergs originated from Greenland and their contribution to freshwater input in the North Atlantic. To do that, we use an interactive iceberg module coupled with the Nucleus for European Modelling of the Ocean (NEMO v3.4), which will calve icebergs from Greenland according to rates established by Bamber et al. (2012). Details on the distribution and trajectory of icebergs within the model may also be of use for understanding potential navigation threats, as shipping increases in northern waters.

greenland_summer_campaign

NASA Image and Video Library

2015-08-28

Laurence Smith, chair of geography at University of California, Los Angeles, deploys an autonomous drift boat equipped with several sensors in a meltwater river on the surface of the Greenland ice sheet on July 19, 2015. “Surface melting in Greenland has increased recently, and we lacked a rigorous estimate of the water volumes being produced and their transport,” said Tom Wagner, the cryosphere program scientist at NASA Headquarters in Washington. “NASA funds fieldwork like Smith’s because it helps us to interpret satellite data, and to extrapolate measurements from the local field sites to the larger ice sheet." Credit: NASA/Goddard/Jefferson Beck

Cloning and sequence analysis of a full-length cDNA of SmPP1cb encoding turbot protein phosphatase 1 beta catalytic subunit

NASA Astrophysics Data System (ADS)

Qi, Fei; Guo, Huarong; Wang, Jian

2008-02-01

Reversible protein phosphorylation, catalyzed by protein kinases and phosphatases, is an important and versatile mechanism by which eukaryotic cells regulate almost all the signaling processes. Protein phosphatase 1 (PP1) is the first and well-characterized member of the protein serine/threonine phosphatase family. In the present study, a full-length cDNA encoding the beta isoform of the catalytic subunit of protein phosphatase 1(PP1cb), was for the first time isolated and sequenced from the skin tissue of flatfish turbot Scophthalmus maximus, designated SmPP1cb, by the rapid amplification of cDNA ends (RACE) technique. The cDNA sequence of SmPP1cb we obtained contains a 984 bp open reading frame (ORF), flanked by a complete 39 bp 5' untranslated region and 462 bp 3' untranslated region. The ORF encodes a putative 327 amino acid protein, and the N-terminal section of this protein is highly acidic, Met-Ala-Glu-Gly-Glu-Leu-Asp-Val-Asp, a common feature for PP1 catalytic subunit but absent in protein phosphatase 2B (PP2B). And its calculated molecular mass is 37 193 Da and pI 5.8. Sequence analysis indicated that, SmPP1cb is extremely conserved in both amino acid and nucleotide acid levels compared with the PP1cb of other vertebrates and invertebrates, and its Kozak motif contained in the 5'UTR around ATG start codon is GXXAXXGXX ATGG, which is different from mammalian in two positions A-6 and G-3, indicating the possibility of different initiation of translation in turbot, and also the 3'UTR of SmPP1cb is highly diverse in the sequence similarity and length compared with other animals, especially zebrafish. The cloning and sequencing of SmPP1cb gene lays a good foundation for the future work on the biological functions of PP1 in the flatfish turbot.

Recent Changes in Arctic Glaciers, Ice Caps, and the Greenland Ice Sheet: Cold Facts About Warm Ice

NASA Astrophysics Data System (ADS)

Abdalati, W.

2005-12-01

One of the major manifestations of Arctic change can be observed in the state of balance of Arctic glaciers and ice caps and the Greenland ice sheet. These ice masses are estimated to contain nearly 3 million cubic kilometers of ice, which is more than six times greater than all the water stored in the Earth's lakes, rivers, and snow combined and is the equivalent of over 7 meters of sea level. Most of these ice masses have been shrinking in recent in years, but their mass balance is highly variable on a wide range of spatial and temporal scales. On the Greenland ice sheet most of the coastal regions have thinned substantially as melt has increased and some of its outlet glaciers have accelerated. Near the equilibrium line in West Greenland, we have seen evidence of summer acceleration that is linked to surface meltwater production, suggesting a relatively rapid response mechanism of the ice sheet change to a warming climate. At the same time, however, the vast interior regions of the Greenland ice sheet have shown little change or slight growth, as accumulation in these areas may have increased. Throughout much of the rest of the Arctic, many glaciers and ice caps have been shrinking in the past few decades, and in Canada and Alaska, the rate of ice loss seems to have accelerated during the late 1990s. These recent observations offer only a snapshot in time of the long-term behavior, but they are providing crucial information about the current state of ice mass balance and the mechanisms that control it in one of the most climatically sensitive regions on Earth. As we continue to learn more through a combination of remote sensing observations, in situ measurements and improved modeling capabilities, it is important that we coordinate and integrate these approaches effectively in order to predict future changes and their impact on sea level, freshwater discharge, and ocean circulation.

Adventure Learning @ Greenland

NASA Astrophysics Data System (ADS)

Miller, B. G.; Cox, C. J.; Hougham, J.; Walden, V. P.; Eitel, K.; Albano, A.

2013-12-01

Teaching the general public and K-12 communities about scientific research has taken on greater importance as climate change increasingly impacts the world we live in. Science researchers and the educational community have a widening responsibility to produce and deliver curriculum and content that is timely, scientifically sound and engaging. To address this challenge, in the summer of 2012 the Adventure Learning @ Greenland (AL@GL) project, a United States' National Science Foundation (NSF) funded initiative, used hands-on and web-based climate science experiences for high school students to promote climate and science literacy. This presentation will report on an innovative approach to education and outreach for environmental science research known as Adventure Learning (AL). The purpose of AL@GL was to engage high school students in the US, and in Greenland, in atmospheric research that is being conducted in the Arctic to enhance climate and science literacy. Climate and science literacy was explored via three fundamental concepts: radiation, the greenhouse effect, and climate vs. weather. Over the course of the project, students in each location engaged in activities and conducted experiments through the use of scientific instrumentation. Students were taught science research principles associated with an atmospheric observatory at Summit Station, Greenland with the objective of connecting climate science in the Arctic to student's local environments. Summit Station is located on the Greenland Ice Sheet [72°N, 38°W, 3200 m] and was the primary location of interest. Approximately 35 students at multiple locations in Idaho, USA, and Greenland participated in the hybrid learning environments as part of this project. The AL@GL project engaged students in an inquiry-based curriculum with content that highlighted a cutting-edge geophysical research initiative at Summit: the Integrated Characterization of Energy, Clouds, Atmospheric state, and Precipitation at

Vegetation Greenness and Its Drivers across Ice-free Greenland

NASA Astrophysics Data System (ADS)

Pedersen, S. H.; Liston, G. E.; Tamstorf, M. P.; Schmidt, N. M.

2017-12-01

The coastal and mountain areas surrounding the Greenland Ice Sheet cover one-fifth of Greenland. This ice-free area spans more than 20 degrees latitude and includes high-, low-, and sub-Arctic climate zones and the terrain varies from sea level to 3700 m elevation. Hence, this area contains a wide range of vegetation growing conditions associated with precipitation, temperature, and incoming solar radiation found across these latitudinal, elevational, and coast-inland gradients. In this study, we mapped the spatial distribution of vegetation at 300-m spatial resolution across ice-free Greenland using the annual maximum vegetation greenness (MaxNDVI) and the timing of MaxNDVI derived from daily Moderate Resolution Imaging Spectroradiometer (MODIS) reflectance data from 2000-2015. Further, we investigated the drivers of the annual MaxNDVI and its timing across the diverse vegetation growing conditions in Greenland using modeled climatic variables, including snow quantity and timing, at the same temporal and spatial resolutions. The annual average MaxNDVI varied between 0.3 and 0.5 in North Greenland, and 0.6 and 0.9 in South Greenland. The timing of MaxNDVI differed more than two weeks between North and South Greenland. The potential growing season, e.g., the period with no snow on the ground, was as short as one month in North Greenland (mainly August), and four to five times longer in South Greenland (typically starting in mid-May). The snow-free date varied with elevation, from valley bottoms to the mountain tops, having the same range that existed from South to North Greenland. Our results show that MaxNDVI and its timing are significantly driven by the timing of snow-free ground and the amount of meltwater available from the snowpack during spring snowmelt.

First Younger Dryas moraines in Greenland

NASA Astrophysics Data System (ADS)

Funder, Svend; Larsen, Nicolaj K.; Linge, Henriette; Möller, Per; Schomacker, Anders; Fabel, Derek; Kjær, Kurt H.; Xu, Sheng

2016-04-01

Over the Greenland ice sheet the Younger Dryas (YD) cold climate oscillation (12.9-11.7 kaBP) began with up to 10°C drop in temperatures and ended with up to 12°C abrupt warming. In the light of the present warming and melting of the ice sheet, and its importance for future climate change, the ice sheet's response to these dramatic changes in the past is of great interest. However, even though much effort has gone into charting YD ice margin behaviour around Greenland in recent years, no clear-cut signal of response to the oscillation has been uncovered. Here we show evidence to suggest that three major outlets from a local ice cap at Greenland's north coast advanced and retreated synchronously during YD. The evidence comprises OSL (optically stimulated luminescence) dates from a marine transgression of the coastal valleys that preceded the advance, and exposure ages from boulders on the moraines, formed by glaciers that overrode the marine sediment. The OSL ages suggest a maximum age of 12.4 ±0.6 kaBP for the marine incursion, and 10 exposure ages on boulders from the three moraines provide an average minimum age of 12.5 ±0.7 kaBP for the moraines, implying that the moraines were formed within the interval 11.8-13.0 kaBP. Elsewhere in Greenland evidence for readvance has been recorded in two areas. Most notably, in the East Greenland fjord zone outlet glaciers over a stretch of 800 km coast advanced through the fjords. In Scoresby Sund, where the moraines form a wide belt, an extensive 14C and exposure dating programme has shown that the readvance here probably culminated before YD, while cessation of moraine formation and rapid retreat from the moraine belt did not commence until c. 11.5 kaBP, but no moraines have so far been dated to YD. Readvance is also seen in Disko Bugt, the largest ice sheet outlet in West Greenland. However, here the advance and retreat of the ice stream took place in mid YD times, and lasted only a few hundred years, while YD in

Bacterial and primary production in the Greenland Sea

NASA Astrophysics Data System (ADS)

Børsheim, Knut Yngve

2017-12-01

Bacterial production rates were measured in water profiles collected in the Greenland Sea and adjacent areas. Hydrography and nutrients throughout the water column were measured along 75°N from 12°W to 10°E at 20 km distance intervals. Net primary production rates from satellite sensed data were compared with literature values from 14C incubations and used for regional and seasonal comparisons. Maximum bacterial production rates were associated with the region close to the edge of the East Greenland current, and the rates decreased gradually towards the center of the Greenland Sea central gyre. Integrated over the upper 20 m the maximum bacterial production rate was 17.9 mmol C m- 2 day- 1, and east of the center of the gyre the average integrated rate was 4.6 mmol C m- 2 day- 1. It is hypothesized that high bacterial production rates in the western Greenland Sea were sustained by organic material carried from the Arctic Ocean by the East Greenland Current. The depth profiles of nitrate and phosphate were very similar both sides of the Arctic front, with 2% higher values between 500 m and 2000 m in the Arctic domain, and a N/P ratio of 13.6. The N/Si ratio varied by depth and region, with increasing silicate depletion from 1500 m depth to the surface. The rate of depletion from 1500 m depth to surface in the Atlantic domain was twice as high as in the Arctic domain. Net primary production rates in the area between the edge of the East Greenland current and the center of the Greenland Sea gyre was 96 mmol C m- 2 day- 1 at the time of the expedition in 2006, and 78 mmol C m- 2 day- 1 east of the center including the Atlantic domain. Annual net primary production estimated from satellite data in the Greenland Sea increased substantially in the period between 2003 and 2016, and the rate of increase was lowest close to the East Greenland Current.

High-Resolution Rayleigh Wave Group Velocity Variation Beneath Greenland

NASA Astrophysics Data System (ADS)

Pourpoint, Maeva; Anandakrishnan, Sridhar; Ammon, Charles J.

2018-02-01

We present a high-resolution group velocity model of Greenland from the analysis of fundamental mode Rayleigh waves. Regional and teleseismic events recorded by the Greenland Ice Sheet Monitoring Network seismic network were used and we developed a group velocity correction method to estimate the dispersion within our region of study. The global dispersion model GDM52 from Ekström (2011, https://doi.org/10.1111/j.1365-246X.2011.05225.x) was used to calculate group delays from the earthquake to the boundaries of our study area. An iterative reweighted generalized least squares approach was then used to invert for the regional group velocity variations between periods of 25 s and 180 s. The group delay correction method helps alleviate the limitations of the sparse Greenland seismic network in a region with poor seismicity. Both the ray coverage and resolution of our model are significantly better than similar studies of Greenland using two-station methods. Spike tests suggest that features as small as 200 km can be resolved across Greenland. Our dispersion maps are consistent with previous studies and reveal many signatures of known geologic features including known sedimentary basins in Baffin Bay, the West and East Greenland flood basalt provinces, the East and South Greenland Archean blocks. Our model also contains two prominent features: a deep high-velocity anomaly extending from northwestern to southwestern Greenland that could be the signature of a cratonic root and a low-velocity anomaly in central eastern Greenland that correlates with the Icelandic plume track and could be associated with lithospheric thinning and upwelling of hot asthenosphere material.

Palatability of water-soluble extracts of protein sources and replacement of fishmeal by a selected mixture of protein sources for juvenile turbot ( Scophthalmus maximus)

NASA Astrophysics Data System (ADS)

Dong, Chun; He, Gen; Mai, Kangsen; Zhou, Huihui; Xu, Wei

2016-06-01

Poor palatability is a limiting factor for replacing fishmeal with other protein sources in aquaculture. The water-soluble molecules with low molecular weights are the major determinants of the palatability of diets. The present study was conducted to investigate the palatability of water-soluble extracts from single protein source (single extract pellets) and the mixture of these extracts with different proportions (blended extract pellets) in juvenile turbot ( Scophthalmus maximus). Then according to the palatability of blended extract pellets, an optimal mixture proportion was selected, and a new protein source made from raw protein materials with the selected proportion was formulated to replace fishmeal. Summarily, the palatability of single extract pellets for turbot was descendent from fishmeal to pet-food grade poultry by-product meal, wheat gluten meal, soybean meal, peanut meal, meat and bone meal, and corn gluten meal. Subsequently, according to the palatability of single extract pellets, 52 kinds of blended extract pellets were designed to test their palatability. The results showed that the pellets presented remarkably different palatability, and the optimal one was diet 52 (wheat gluten meal: pet-food grade poultry by-product meal: meat and bone meal: corn gluten meal = 1:6:1:2). The highest ingestion ratio (the number of pellets ingested/the number of pellets fed) was 0.73 ± 0.03, which was observed in Diet 52. Then five isonitrogenous (52% crude protein) and isocaloric (20 kJ g-1 gross energy) diets were formulated by replacing 0 (control), 35%, 50%, 65% and 80% of fishmeal with No.52 blending proportion. After a 10-weeks feeding trial, a consistent feed intake was found among all replacement treatments. Replacement level of fishmeal up to 35% did not significantly influence final body weight, specific growth rate, feed efficiency ratio, and protein efficiency ratio of turbot. Therefore, the water-soluble extracts of protein sources play an

Earthquake Activity in the North Greenland Region

NASA Astrophysics Data System (ADS)

Larsen, Tine B.; Dahl-Jensen, Trine; Voss, Peter H.

2017-04-01

Many local and regional earthquakes are recorded on a daily basis in northern Greenland. The majority of the earthquakes originate at the Arctic plate boundary between the Eurasian and the North American plates. Particularly active regions away from the plate boundary are found in NE Greenland and in northern Baffin Bay. The seismograph coverage in the region is sparse with the main seismograph stations located at the military outpost, Stations Nord (NOR), the weather station outpost Danmarkshavn (DAG), Thule Airbase (TULEG), and the former ice core drilling camp (NEEM) in the middle of the Greenland ice sheet. Furthermore, data is available from Alert (ALE), Resolute (RES), and other seismographs in northern Canada as well as from a temporary deployment of BroadBand seismographs along the north coast of Greenland from 2004 to 2007. The recorded earthquakes range in magnitude from less than 2 to a 4.8 event, the largest in NE Greenland, and a 5.7 event, the largest recorded in northern Baffin Bay. The larger events are recorded widely in the region allowing for focal mechanisms to be calculated. Only a few existing focal mechanisms for the region can be found in the ISC bulletin. Two in NE Greenland representing primarily normal faulting and one in Baffin Bay resulting from reverse faulting. New calculations of focal mechanisms for the region will be presented as well as improved hypocenters resulting from analysis involving temporary stations and regional stations that are not included in routine processing.

Resolving bathymetry from airborne gravity along Greenland fjords

USGS Publications Warehouse

Boghosian, Alexandra; Tinto, Kirsty; Cochran, James R.; Porter, David; Elieff, Stefan; Burton, Bethany L.; Bell, Robin E.

2015-01-01

Recent glacier mass loss in Greenland has been attributed to encroaching warming waters, but knowledge of fjord bathymetry is required to investigate this mechanism. The bathymetry in many Greenland fjords is unmapped and difficult to measure. From 2010 to 2012, National Aeronautics and Space Administration's Operation IceBridge collected a unique set of airborne gravity, magnetic, radar, and lidar data along the major outlet glaciers and fjords in Greenland. We applied a consistent technique using the IceBridge gravity data to create 90 bathymetric profiles along 54 Greenland fjords. We also used this technique to recover subice topography where warm or crevassed ice prevents the radar system from imaging the bed. Here we discuss our methodology, basic assumptions and error analysis. We present the new bathymetry data and discuss observations in six major regions of Greenland covered by IceBridge. The gravity models provide a total of 1950 line kilometers of bathymetry, 875 line kilometers of subice topography, and 12 new grounding line depths.

Nuuk, Greenland

NASA Technical Reports Server (NTRS)

2008-01-01

Nuuk (or Gadthab) is the capital and largest city of Greenland. It is located at the mouth of the Nuup Kangerlua inlet on the west coast of Greenland. It has a population of about 15,000. The site has a long history of different inhabitation: first by the Inuit people around 2000 B.C., later by Viking explorers in the 10th century. Inuit and Vikings lived together for about 500 years until about 1500, when human habitation suddenly stopped, most likely due to change in climate and vegetation.

The image was acquired August 2, 2004, covers an area of 22.7 x 26 km, and is located at 64.2 degrees north latitude, 51.8 degrees west longitude.

The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

Malaspina Glacier, Alaska

NASA Image and Video Library

2017-12-08

The ice of a piedmont glacier spills from a steep valley onto a relatively flat plain, where it spreads out unconstrained like pancake batter. Elephant Foot Glacier in northeastern Greenland is an excellent example; it is particularly noted for its symmetry. But the largest piedmont glacier in North America (and possibly the world) is Malaspina in southeastern Alaska. On September 24, 2014, the Operational Land Imager (OLI) on Landsat 8 acquired this image of Malaspina Glacier. The main source of ice comes from Seward Glacier, located at the top-center of this image. The Agassiz and Libbey glaciers are visible on the left side, and the Hayden and Marvine glaciers are on the right. The brown lines on the ice are moraines—areas where soil, rock, and other debris have been scraped up by the glacier and deposited at its sides. Where two glaciers flow together, the moraines merge to form a medial moraine. Glaciers that flow at a steady speed tend to have moraines that are relatively straight. But what causes the dizzying pattern of curves, zigzags, and loops of Malaspina’s moraines? Glaciers in this area of Alaska periodically “surge,”meaning they lurch forward quickly for one to several years. As a result of this irregular flow, the moraines at the edges and between glaciers can become folded, compressed, and sheared to form the characteristic loops seen on Malaspina. For instance, a surge in 1986 displaced moraines on the east side of Malaspina by as much as 5 kilometers (3 miles). NASA Earth Observatory image by Jesse Allen, using Landsat data from the U.S. Geological Survey. Caption by Kathryn Hansen. Credit: NASA Earth Observatory NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission

Distribution of Alexandrium fundyense (Dinophyceae) cysts in Greenland and Iceland, with an emphasis on viability and growth in the Arctic

PubMed Central

Richlen, Mindy L.; Zielinski, Oliver; Holinde, Lars; Tillmann, Urban; Cembella, Allan; Lyu, Yihua; Anderson, Donald M.

2016-01-01

The bloom-forming dinoflagellate Alexandrium fundyense has been extensively studied due its toxin-producing capabilities and consequent impacts to human health and economies. This study investigated the prevalence of resting cysts of A. fundyense in western Greenland and Iceland to assess the historical presence and magnitude of bloom populations in the region, and to characterize environmental conditions during summer, when bloom development may occur. Analysis of sediments collected from these locations showed that Alexandrium cysts were present at low to moderate densities in most areas surveyed, with highest densities observed in western Iceland. Additionally, laboratory experiments were conducted on clonal cultures established from isolated cysts or vegetative cells from Greenland, Iceland, and the Chukchi Sea (near Alaska) to examine the effects of photoperiod interval and irradiance levels on growth. Growth rates in response to the experimental treatments varied among isolates, but were generally highest under conditions that included both the shortest photoperiod interval (16h:8h light:dark) and higher irradiance levels (~146–366 μmol photons m−2 s−1), followed by growth under an extended photoperiod interval and low irradiance level (~37 μmol photons m−2 s−1). Based on field and laboratory data, we hypothesize that blooms in Greenland are primarily derived from advected Alexandrium populations, as low bottom temperatures and limited light availability would likely preclude in situ bloom development. In contrast, the bays and fjords in Iceland may provide more favorable habitat for germling cell survival and growth, and therefore may support indigenous, self-seeding blooms. PMID:27721528

Greenland ice cores tell tales on past sea level changes

NASA Astrophysics Data System (ADS)

Dahl-Jensen, D.

2017-12-01

All the deep ice cores drilled to the base of the Greenland ice sheet contain ice from the previous warm climate period, the Eemian 130-115 thousand years before present. This demonstrates the resilience of the Greenland ice sheet to a warming of 5 oC. Studies of basal material further reveal the presence of boreal forest over Greenland before ice covered Greenland. Conditions for Boreal forest implies temperatures at this time has been more than 10 oC warmer than the present. To compare the paleo-behavior of the Greenland ice sheet to the present in relation to sea level rise knowledge gabs include the reaction of ice streams to climate changes. To address this the international EGRIP-project is drilling an ice core in the center of the North East Greenland Ice Stream (NEGIS). The first results will be presented.

Earthshots: Satellite images of environmental change – Petermann Glacier, Greenland

USGS Publications Warehouse

Adamson, Thomas

2016-01-01

This calving is normal, but it’s worth watching Petermann and other Greenland glaciers closely. Petermann is one of the major marine-terminating glaciers of Greenland. Ice loss from the Greenland Ice Sheet has increased recently. An article in Nature concluded that climate change may cause Petermann and other Greenland glaciers to contribute to sea level rise. Landsat helps glaciologists keep a close eye on this remote but significant glacier.

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SIMPL/AVIRIS-NG Greenland 2015: Flight Report

NASA Technical Reports Server (NTRS)

Brunt, Kelly M.; Neumann, Thomas A.; Markus, Thorsten

2015-01-01

In August 2015, NASA conducted a two-­aircraft, coordinated campaign based out of Thule Air Base, Greenland, in support of Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) algorithm development. The survey targeted the Greenland Ice Sheet and sea ice in the Arctic Ocean during the summer melt season. The survey was conducted with a photon-counting laser altimeter in one aircraft and an imaging spectrometer in the second aircraft. Ultimately, the mission, SIMPL/AVIRIS-NG Greenland 2015, conducted nine coordinated science flights, for a total of 37 flight hours over the ice sheet and sea ice.

SeaWinds - Greenland

NASA Image and Video Library

2000-05-08

The frequent coverage provided by NASA SeaWinds instrument on the QuikScat satellite in 1999 provided unprecedented capability to monitor daily and seasonal changes in the key melt zones of Greenland.

Polar continental margins: Studies off East Greenland

NASA Astrophysics Data System (ADS)

Mienert, J.; Thiede, J.; Kenyon, N. H.; Hollender, F.-J.

The passive continental margin off east Greenland has been shaped by tectonic and sedimentary processes, and typical physiographic patterns have evolved over the past few million years under the influence of the late Cenozoic Northern Hemisphere glaciations. The Greenland ice shield has been particularly affected.GLORIA (Geological Long Range Inclined Asdic), the Institute of Oceanographic Sciences' (IOS) long-range, side-scan sonar, was used on a 1992 RV Livonia cruise to map large-scale changes in sedimentary patterns along the east Greenland continental margin. The overall objective of this research program was to determine the variety of large-scale seafloor processes to improve our understanding of the interaction between ice sheets, current regimes, and sedimentary processes. In cooperation with IOS and the RV Livonia, a high-quality set of seafloor data has been produced. GLORIA'S first survey of east Greenland's continental margin covered several 1000- × 50-km-wide swaths (Figure 1) and yielded an impressive sidescan sonar image of the complete Greenland Basin and margin (about 250,000 km2). A mosaic of the data was made at a scale of 1:375,000. The base map was prepared with a polar stereographic projection having a standard parallel of 71°.

Pathways of warm water to the Northeast Greenland outlet glaciers

NASA Astrophysics Data System (ADS)

Schaffer, Janin; Timmermann, Ralph; Kanzow, Torsten; Arndt, Jan Erik; Mayer, Christoph; Schauer, Ursula

2015-04-01

The ocean plays an important role in modulating the mass balance of the Greenland Ice Sheet by delivering heat to the marine-terminating outlet glaciers surrounding the Greenland coast. The warming and accumulation of Atlantic Water in the subpolar North Atlantic has been suggested to be a potential driver of the glaciers' retreat over the last decades. The shelf regions thus play a critical role for the transport of Atlantic Water towards the glaciers, but also for the transfer of freshwater towards the deep ocean. A key region for the mass balance of the Greenland Ice Sheet is the Northeast Greenland Ice Stream. This large ice stream drains the second-largest basin of the Greenland Ice Sheet and feeds three outlet glaciers. The largest one is Nioghalvfjerdsfjorden (79°N-Glacier) featuring an 80 km long floating ice tongue. Both the ocean circulation on the continental shelf off Northeast Greenland and the circulation in the cavity below the ice tongue are weakly constrained so far. In order to study the relevant processes of glacier-ocean interaction we combine observations and model work. Here we focus on historic and recent hydrographic observations and on the complex bathymetry in the Northeast Greenland shelf region, which is thought to steer the flux of warm Atlantic water onto the continental shelf and into the sub-ice cavity beneath the 79°N-Glacier. We present a new global topography data set, RTopo-2, which includes the most recent surveys on the Northeast Greenland continental shelf and provides a detailed bathymetry for all around Greenland. In addition, RTopo-2 contains ice and bedrock surface topographies for Greenland and Antarctica. Based on the updated ocean bathymetry and a variety of hydrographic observations we show the water mass distribution on the continental shelf off Northeast Greenland. These maps enable us to discuss possible supply pathways of warm modified Atlantic waters on the continental shelf and thus potential ways of heat

South Greenland, North Atlantic Ocean

NASA Technical Reports Server (NTRS)

1992-01-01

This spectacular north looking view of south Greenland (62.0N, 46.0W) shows numerous indentations along the coastline, many of which contain small settlements. These indentations are fiords carved by glaciers of the last ice age. Even today, ice in the center of Greenland is as much as 10,000 ft. thick and great rivers of ice continuously flow toward the sea, where they melt or break off as icebergs - some of which may be seen floating offshore.

South Greenland, North Atlantic Ocean

NASA Image and Video Library

1992-04-02

This spectacular north looking view of south Greenland (62.0N, 46.0W) shows numerous indentations along the coastline, many of which contain small settlements. These indentations are fiords carved by glaciers of the last ice age. Even today, ice in the center of Greenland is as much as 10,000 ft. thick and great rivers of ice continuously flow toward the sea, where they melt or break off as icebergs - some of which may be seen floating offshore.

State of Alaska

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Role of Greenland meltwater in the changing Arctic

NASA Astrophysics Data System (ADS)

Dukhovskoy, Dmitry; Proshutinsky, Andrey; Timmermans, Mary-Louise; Myers, Paul; Platov, Gennady; Bamber, Jonathan; Curry, Beth; Somavilla, Raquel

2016-04-01

Observational data show that the Arctic ocean-ice-atmosphere system has been changing over the last two decades. Arctic change is manifest in the atypical behavior of the climate indices in the 21st century. Before the 2000s, these indices characterized the quasi-decadal variability of the Arctic climate related to different circulation regimes. Between 1948 and 1996, the Arctic atmospheric circulation alternated between anticyclonic circulation regimes and cyclonic circulation regimes with a period of 10-15 years. Since 1997, however, the Arctic has been dominated by an anticyclonic regime. Previous studies indicate that in the 20th century, freshwater and heat exchange between the Arctic Ocean and the sub-Arctic seas were self-regulated and their interactions were realized via quasi-decadal climate oscillations. What physical processes in the Arctic Ocean - sub-Arctic ocean-ice-atmosphere system are responsible for the observed changes in Arctic climate variability? The presented work is motivated by our hypothesis that in the 21st century, these quasi-decadal oscillations have been interrupted as a result of an additional freshwater source associated with Greenland Ice Sheet melt. Accelerating since the early 1990s, the Greenland Ice Sheet mass loss exerts a significant impact on thermohaline processes in the sub-Arctic seas. Surplus Greenland freshwater, the amount of which is about a third of the freshwater volume fluxed into the region during the 1970s Great Salinity Anomaly event, can spread and accumulate in the sub-Arctic seas influencing convective processes there. It is not clear, however, whether Greenland freshwater can propagate into the interior convective regions in the Labrador Sea and the Nordic Seas. In order to investigate the fate and pathways of Greenland freshwater in the sub-Arctic seas and to determine how and at what rate Greenland freshwater propagates into the convective regions, several numerical experiments using a passive tracer to

Balance Velocities of the Greenland Ice Sheet

NASA Technical Reports Server (NTRS)

Joughin, Ian; Fahnestock, Mark; Ekholm, Simon; Kwok, Ron

1997-01-01

We present a map of balance velocities for the Greenland ice sheet. The resolution of the underlying DEM, which was derived primarily from radar altimetry data, yields far greater detail than earlier balance velocity estimates for Greenland. The velocity contours reveal in striking detail the location of an ice stream in northeastern Greenland, which was only recently discovered using satellite imagery. Enhanced flow associated with all of the major outlets is clearly visible, although small errors in the source data result in less accurate estimates of the absolute flow speeds. Nevertheless, the balance map is useful for ice-sheet modelling, mass balance studies, and field planning.

Results and Error Estimates from GRACE Forward Modeling over Greenland, Canada, and Alaska

NASA Astrophysics Data System (ADS)

Bonin, J. A.; Chambers, D. P.

2012-12-01

Forward modeling using a weighted least squares technique allows GRACE information to be projected onto a pre-determined collection of local basins. This decreases the impact of spatial leakage, allowing estimates of mass change to be better localized. The technique is especially valuable where models of current-day mass change are poor, such as over Greenland and Antarctica. However, the accuracy of the forward model technique has not been determined, nor is it known how the distribution of the local basins affects the results. We use a "truth" model composed of hydrology and ice-melt slopes as an example case, to estimate the uncertainties of this forward modeling method and expose those design parameters which may result in an incorrect high-resolution mass distribution. We then apply these optimal parameters in a forward model estimate created from RL05 GRACE data. We compare the resulting mass slopes with the expected systematic errors from the simulation, as well as GIA and basic trend-fitting uncertainties. We also consider whether specific regions (such as Ellesmere Island and Baffin Island) can be estimated reliably using our optimal basin layout.

GeoFORCE Alaska, A Successful Summer Exploring Alaska's Geology

NASA Astrophysics Data System (ADS)

Wartes, D.

2012-12-01

Thirty years old this summer, RAHI, the Rural Alaska Honors Institute is a statewide, six-week, summer college-preparatory bridge program at the University of Alaska Fairbanks for Alaska Native and rural high school juniors and seniors. This summer, in collaboration with the University of Texas Austin, the Rural Alaska Honors Institute launched a new program, GeoFORCE Alaska. This outreach initiative is designed to increase the number and diversity of students pursuing STEM degree programs and entering the future high-tech workforce. It uses Earth science to entice kids to get excited about dinosaurs, volcanoes and earthquakes, and includes physics, chemistry, math, biology and other sciences. Students were recruited from the Alaska's Arctic North Slope schools, in 8th grade to begin the annual program of approximately 8 days, the summer before their 9th grade year and then remain in the program for all four years of high school. They must maintain a B or better grade average and participate in all GeoFORCE events. The culmination is an exciting field event each summer. Over the four-year period, events will include trips to Fairbanks and Anchorage, Arizona, Oregon and the Appalachians. All trips focus on Earth science and include a 100+ page guidebook, with tests every night culminating with a final exam. GeoFORCE Alaska was begun by the University of Alaska Fairbanks in partnership with the University of Texas at Austin, which has had tremendous success with GeoFORCE Texas. GeoFORCE Alaska is managed by UAF's long-standing Rural Alaska Honors Institute, that has been successfully providing intense STEM educational opportunities for Alaskan high school students for over 30 years. The program will add a new cohort of 9th graders each year for the next four years. By the summer of 2015, GeoFORCE Alaska is targeting a capacity of 160 students in grades 9th through 12th. Join us to find out more about this exciting new initiative, which is enticing young Alaska Native

Insight into the heat resistance of fish via blood: Effects of heat stress on metabolism, oxidative stress and antioxidant response of olive flounder Paralichthys olivaceus and turbot Scophthalmus maximus.

PubMed

Lu, Yunliang; Wu, Zhihao; Song, Zongcheng; Xiao, Peng; Liu, Ying; Zhang, Peijun; You, Feng

2016-11-01

High temperature has direct confinement on fish survival and growth, especially under the background of global warming. Selection of fish line with heat resistance is an important means to address this problem. In the present study, we analyzed the difference in heat resistance between families of olive flounder Paralichthys olivaceus and turbot Scophthalmus maximus, two flatfish species occupying slightly different thermal niches. Then the chosen families were tested to determine their differential response to heat stress (ΔT = +8 °C and +12 °C) in blood, including anaerobic metabolism (lactate), oxidative stress (lipid peroxidation and protein carbonylation) and antioxidant enzymes. Results showed a difference in heat resistance between families of the two species. Among the chosen parameters, growth traits had a significant effect on contents of lactate and malondialdehyd (MDA), and activities of catalase (CAT) and glutathione S-transferase in flounder (P < 0.05), and on MDA content and CAT activity in turbot (P < 0.05). In comparison with heat-sensitive family of each species, levels of all studied parameters were lower and more stable in heat-resistant families after heat stress. What's more, heat resistance of fish significantly influenced contents of lactate and MDA and activity of CAT in flounder (P < 0.05), as well as contents of lactate, MDA and carbonyl and activity of superoxide dismutate (SOD) in turbot (P < 0.05). These results demonstrated that such physiological phenotypes as anaerobic metabolism, oxidative stress and antioxidant enzymes are good biomarkers of fish heat-resistance, being potentially valuable in fish breeding. However, these markers should be applied with more caution when there is a growth discrepancy between fish families. Copyright © 2016 Elsevier Ltd. All rights reserved.

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Atmospheric Circulation and West Greenland Precipitation

NASA Astrophysics Data System (ADS)

Auger, J.; Birkel, S. D.; Maasch, K. A.; Schuenemann, K. C.; Mayewski, P. A.; Osterberg, E. C.; Hawley, R. L.; Marshall, H. P.

2016-12-01

The surface mass balance of the Greenland Ice Sheet has declined substantially in recent decades across West Greenland with important implications for global sea level and freshwater resources. Here, we investigate changes in heat and moisture delivery to West Greenland through changes in atmospheric circulation in order to gain insight into possible future climate. Particular focus is placed on the role of known climate variability, including the North Atlantic Oscillation (NAO) and Atlantic Multidecadal Oscillation (AMO), in influencing the intensity, frequency, and track of cyclones across the North Atlantic. This study utilizes multiple daily climate reanalysis models (CFSR, ERA-Interim, JRA-55) in addition to observational data. Preliminary results indicate a primary influence from the NAO, with a secondary influence from the low frequency oscillation connected to the AMO. Work is ongoing, and a complete synthesis will be presented at the fall meeting.

Alaska Tidal Datum Portal - Alaska Tidal Datum Calculator | Alaska Division

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Coastal Hazards Program Guide to Geologic Hazards in Alaska MAPTEACH Tsunami Inundation Mapping Energy Portal main content Alaska Tidal Datum Portal Unambiguous vertical datums in the coastal environment are projects to ensure protection of human life, property, and the coastal environment. January 2017 - Update

Greenland coastal air temperatures linked to Baffin Bay and Greenland Sea ice conditions during autumn through regional blocking patterns

NASA Astrophysics Data System (ADS)

Ballinger, Thomas J.; Hanna, Edward; Hall, Richard J.; Miller, Jeffrey; Ribergaard, Mads H.; Høyer, Jacob L.

2018-01-01

Variations in sea ice freeze onset and regional sea surface temperatures (SSTs) in Baffin Bay and Greenland Sea are linked to autumn surface air temperatures (SATs) around coastal Greenland through 500 hPa blocking patterns, 1979-2014. We find strong, statistically significant correlations between Baffin Bay freeze onset and SSTs and SATs across the western and southernmost coastal areas, while weaker and fewer significant correlations are found between eastern SATs, SSTs, and freeze periods observed in the neighboring Greenland Sea. Autumn Greenland Blocking Index values and the incidence of meridional circulation patterns have increased over the modern sea ice monitoring era. Increased anticyclonic blocking patterns promote poleward transport of warm air from lower latitudes and local warm air advection onshore from ocean-atmosphere sensible heat exchange through ice-free or thin ice-covered seas bordering the coastal stations. Temperature composites by years of extreme late freeze conditions, occurring since 2006 in Baffin Bay, reveal positive monthly SAT departures that often exceed 1 standard deviation from the 1981-2010 climate normal over coastal areas that exhibit a similar spatial pattern as the peak correlations.

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How much can Greenland melt? An upper bound on mass loss from the Greenland Ice Sheet through surface melting

NASA Astrophysics Data System (ADS)

Liu, X.; Bassis, J. N.

2015-12-01

With observations showing accelerated mass loss from the Greenland Ice Sheet due to surface melt, the Greenland Ice Sheet is becoming one of the most significant contributors to sea level rise. The contribution of the Greenland Ice Sheet o sea level rise is likely to accelerate in the coming decade and centuries as atmospheric temperatures continue to rise, potentially triggering ever larger surface melt rates. However, at present considerable uncertainty remains in projecting the contribution to sea level of the Greenland Ice Sheet both due to uncertainty in atmospheric forcing and the ice sheet response to climate forcing. Here we seek an upper bound on the contribution of surface melt from the Greenland to sea level rise in the coming century using a surface energy balance model coupled to an englacial model. We use IPCC Representative Concentration Pathways (RCP8.5, RCP6, RCP4.5, RCP2.6) climate scenarios from an ensemble of global climate models in our simulations to project the maximum rate of ice volume loss and related sea-level rise associated with surface melting. To estimate the upper bound, we assume the Greenland Ice Sheet is perpetually covered in thick clouds, which maximize longwave radiation to the ice sheet. We further assume that deposition of black carbon darkens the ice substantially turning it nearly black, substantially reducing its albedo. Although assuming that all melt water not stored in the snow/firn is instantaneously transported off the ice sheet increases mass loss in the short term, refreezing of retained water warms the ice and may lead to more melt in the long term. Hence we examine both assumptions and use the scenario that leads to the most surface melt by 2100. Preliminary models results suggest that under the most aggressive climate forcing, surface melt from the Greenland Ice Sheet contributes ~1 m to sea level by the year 2100. This is a significant contribution and ignores dynamic effects. We also examined a lower bound

Earthquakes in Alaska

USGS Publications Warehouse

Haeussler, Peter J.; Plafker, George

1995-01-01

Earthquake risk is high in much of the southern half of Alaska, but it is not the same everywhere. This map shows the overall geologic setting in Alaska that produces earthquakes. The Pacific plate (darker blue) is sliding northwestward past southeastern Alaska and then dives beneath the North American plate (light blue, green, and brown) in southern Alaska, the Alaska Peninsula, and the Aleutian Islands. Most earthquakes are produced where these two plates come into contact and slide past each other. Major earthquakes also occur throughout much of interior Alaska as a result of collision of a piece of crust with the southern margin.

Fatal outbreak of botulism in Greenland.

PubMed

Hammer, Tóra Hedinsdottir; Jespersen, Sanne; Kanstrup, Jakob; Ballegaard, Vibe Cecilie; Kjerulf, Anne; Gelvan, Allan

2015-03-01

Botulism commonly occurs when the anaerobic, gram-positive bacterium Clostridium botulinum, under suitable conditions, produces botulinum neurotoxins. Named A-F, these toxins are the immediate causative agent of the clinical symptoms of symmetrical, descending neurological deficits, including respiratory muscle paralysis. We present five cases of foodborne botulism occurring in Greenland, two with fatal outcome, caused by ingestion of tradionally preserved eider fowl. In the cases of the survivors, antitoxin and supportive care, including mechanical ventilation, were administered. In these cases recovery was complete. Microbiological assays, including toxin neutralization bioassay, demonstrated the presence of neurotoxin E in two survivors. The third survivor was shown by PCR to have the BoNT type E gene in faeces. This is the first report of cases of fatal botulism in Greenland. It underscores the importance of prompt coordinated case management effort in a geographically isolated area such as Greenland.

Predicting the Geothermal Heat Flux in Greenland: A Machine Learning Approach

NASA Astrophysics Data System (ADS)

Rezvanbehbahani, Soroush; Stearns, Leigh A.; Kadivar, Amir; Walker, J. Doug; van der Veen, C. J.

2017-12-01

Geothermal heat flux (GHF) is a crucial boundary condition for making accurate predictions of ice sheet mass loss, yet it is poorly known in Greenland due to inaccessibility of the bedrock. Here we use a machine learning algorithm on a large collection of relevant geologic features and global GHF measurements and produce a GHF map of Greenland that we argue is within ˜15% accuracy. The main features of our predicted GHF map include a large region with high GHF in central-north Greenland surrounding the NorthGRIP ice core site, and hot spots in the Jakobshavn Isbræ catchment, upstream of Petermann Gletscher, and near the terminus of Nioghalvfjerdsfjorden glacier. Our model also captures the trajectory of Greenland movement over the Icelandic plume by predicting a stripe of elevated GHF in central-east Greenland. Finally, we show that our model can produce substantially more accurate predictions if additional measurements of GHF in Greenland are provided.

Oxidants and anti-oxidants in turbot seminal plasma and their effects on sperm quality

NASA Astrophysics Data System (ADS)

Han, Mingming; Ding, Fuhong; Meng, Zhen; Lei, Jilin

2015-08-01

In this research, the concentration and activity of oxidants and anti-oxidants in turbot semen, and their effects on sperm quality were studied. The results showed that superoxide dismutase (SOD), catalase, glutathione reductase (GR), uric acid, vitamin E (VE) and vitamin C (VC) were more abundant in seminal plasma than in spermatozoa. The variation for each of them was specific. In seminal plasma, the activity of SOD and GR increased from November 15, November 30 to December 15, and then decreased on December 30. The concentrations of both VC and uric acid decreased during the first 3 sampling times and increased on December 30. The oxidants in seminal plasma accumulated to the highest on December 30. Lactic acid (LA) and ATP levels decreased to the lowest on December 30. The correlation analysis showed that GR had the significant positive relevance to sperm motility and VSL/VCL, while ·OH had negative relevance to them.

Greenland-Wide Seasonal Temperatures During the Last Deglaciation

NASA Astrophysics Data System (ADS)

Buizert, C.; Keisling, B. A.; Box, J. E.; He, F.; Carlson, A. E.; Sinclair, G.; DeConto, R. M.

2018-02-01

The sensitivity of the Greenland ice sheet to climate forcing is of key importance in assessing its contribution to past and future sea level rise. Surface mass loss occurs during summer, and accounting for temperature seasonality is critical in simulating ice sheet evolution and in interpreting glacial landforms and chronologies. Ice core records constrain the timing and magnitude of climate change but are largely limited to annual mean estimates from the ice sheet interior. Here we merge ice core reconstructions with transient climate model simulations to generate Greenland-wide and seasonally resolved surface air temperature fields during the last deglaciation. Greenland summer temperatures peak in the early Holocene, consistent with records of ice core melt layers. We perform deglacial Greenland ice sheet model simulations to demonstrate that accounting for realistic temperature seasonality decreases simulated glacial ice volume, expedites the deglacial margin retreat, mutes the impact of abrupt climate warming, and gives rise to a clear Holocene ice volume minimum.

Frozen Greenland Meltpond

NASA Image and Video Library

2017-12-08

Frozen meltwater lake along the northeast Greenland coast, as seen from NASA's P-3B aircraft on May 7, 2012. Credit: NASA/Jim Yungel =========== IceBridge, a six-year NASA mission, is the largest airborne survey of Earth's polar ice ever flown. It will yield an unprecedented three-dimensional view of Arctic and Antarctic ice sheets, ice shelves and sea ice. These flights will provide a yearly, multi-instrument look at the behavior of the rapidly changing features of the Greenland and Antarctic ice. Data collected during IceBridge will help scientists bridge the gap in polar observations between NASA's Ice, Cloud and Land Elevation Satellite (ICESat) -- in orbit since 2003 -- and ICESat-2, planned for early 2016. ICESat stopped collecting science data in 2009, making IceBridge critical for ensuring a continuous series of observations. IceBridge will use airborne instruments to map Arctic and Antarctic areas once a year. IceBridge flights are conducted in March-May over Greenland and in October-November over Antarctica. Other smaller airborne surveys around the world are also part of the IceBridge campaign. To read more about IceBridge - Arctic 2012 go to: www.nasa.gov/mission_pages/icebridge/index.html NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Alaska and the Alaska Federal Health Care Partnership

DTIC Science & Technology

2002-08-01

SUPPLEMENTARY NOTES The original document contains color images. 14. ABSTRACT The intent of the Alaska Federal Healthcare Partnership is to expand clinical and... intent of the Alaska Federal Healthcare Partnership is to expand clinical and support capabilities of the Alaska Native Medical Center (ANMC), Third...the formation of the Partnership. Although lengthy, the information is essential to appreciate the magnitude of the Partnership and the intent behind

Imaging the Iceland Hotspot Track Beneath Greenland with Seismic Noise Correlations

NASA Astrophysics Data System (ADS)

Mordret, A.

2017-12-01

During the past 65 million years, the Greenland craton drifted over the Iceland hotspot; however, uncertainties in geodynamic modeling and a lack of geophysical evidence prevent an accurate reconstruction of the hotspot track. I image the Greenland lithosphere down to 300 km depth with seismic noise tomography. The hotspot track is observed as a linear high-velocity anomaly in the middle crust associated with magmatic intrusions. In the upper mantle, the remnant thermal signature of the hotspot manifests as low velocity and low viscosity bodies. This new detailed picture of the Greenland lithosphere will drive more accurate geodynamic reconstructions of tectonic plate motions and prediction of Greenland heat flow, which in turn will enable more precise estimations of the Greenland ice-sheet mass balance.

Instrumentation for single-dish observations with The Greenland Telescope

NASA Astrophysics Data System (ADS)

Grimes, Paul K.; Asada, K.; Blundell, R.; Burgos, R.; Chang, H.-H.; Chen, M. T.; Goldie, D.; Groppi, C.; Han, C. C.; Ho, P. T. P.; Huang, Y. D.; Inoue, M.; Kubo, D.; Koch, P.; Leech, J.; de Lera Acedo, E.; Martin-Cocher, P.; Nishioka, H.; Nakamura, M.; Matsushita, S.; Paine, S. N.; Patel, N.; Raffin, P.; Snow, W.; Sridharan, T. K.; Srinivasan, R.; Thomas, C. N.; Tong, E.; Wang, M.-J.; Wheeler, C.; Withington, S.; Yassin, G.; Zeng, L.-Z.

2014-07-01

The Greenland Telescope project will deploy and operate a 12m sub-millimeter telescope at the highest point of the Greenland i e sheet. The Greenland Telescope project is a joint venture between the Smithsonian As- trophysical Observatory (SAO) and the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA). In this paper we discuss the concepts, specifications, and science goals of the instruments being developed for single-dish observations with the Greenland Telescope, and the coupling optics required to couple both them and the mm-VLBI receivers to antenna. The project will outfit the ALMA North America prototype antenna for Arctic operations and deploy it to Summit Station,1 a NSF operated Arctic station at 3,100m above MSL on the Greenland I e Sheet. This site is exceptionally dry, and promises to be an excellent site for sub-millimeter astronomical observations. The main science goal of the Greenland Telescope is to carry out millimeter VLBI observations alongside other telescopes in Europe and the Americas, with the aim of resolving the event horizon of the super-massive black hole at the enter of M87. The Greenland Telescope will also be outfitted for single-dish observations from the millimeter-wave to Tera-hertz bands. In this paper we will discuss the proposed instruments that are currently in development for the Greenland Telescope - 350 GHz and 650 GHz heterodyne array receivers; 1.4 THz HEB array receivers and a W-band bolometric spectrometer. SAO is leading the development of two heterodyne array instruments for the Greenland Telescope, a 48- pixel, 325-375 GHz SIS array receiver, and a 4 pixel, 1.4 THz HEB array receiver. A key science goal for these instruments is the mapping of ortho and para H2D+ in old protostellar ores, as well as general mapping of CO and other transitions in molecular louds. An 8-pixel prototype module for the 350 GHz array is currently being built for laboratory and operational testing on the Greenland Telescope

Arctic Ocean UNCLOS Article 76 Work for Greenland Starts on Land

NASA Astrophysics Data System (ADS)

Dahl-Jensen, T.; Marcussen, C.; Jackson, R.; Voss, P.

2005-12-01

One of the most lonely and desolate stretches of coastline on the planet has become the target for UNCLOS article 76 related research. The Danish Continental Shelf Project has launched a work program to investigate the possibilities for Greenland to claim an area outside the 200 nm limit in the Arctic Ocean. The role of the Lomonosov Ridge as a Natural Prolongation of Greenland/Canada is an important issue, and in order to better evaluate the connection between Greenland and the Lomonosov Ridge the nature of not only the ridge but also of Northern Greenland is the target of deep crustal investigations. The North Greenland Fold belt covers the ice-free part of North Greenland and continues west in the Canadian Arctic. The foldbelt was formed during the Ellesmerian orogeny, where sediments from the Franklinian Basin where compressed and deformed. The deep structure of basin and its subsequent closure are broadly unknown. Three broad band earthquake seismological stations where installed in North Greenland to supplement the existing stations at Alert (Canada) and Station Nord to the east, and the first data was available summer 2005. Crustal thickness data from these first results are presented. Plans for the spring 2006 consist of wide-angle acquisition on the sea ice from the Greenland-Canadian mainland out onto the Lomonosov Ridge, a joint Danish - Canadian project with a 400 km long profile over difficult ice conditions, 18 tons of explosives, three helicopters, a Twin Otter and about 30 participants.

Determination of internal controls for quantitative real time RT-PCR analysis of the effect of Edwardsiella tarda infection on gene expression in turbot (Scophthalmus maximus).

PubMed

Dang, Wei; Sun, Li

2011-02-01

In recent years, quantitative real time reverse transcriptase-PCR (qRT-PCR) has been used frequently in the study of gene expression in turbot (Scophthalmus maximus) in relation to bacterial infection. However, no investigations on appropriate qRT-PCR reference genes have been documented. In this report, we determined the potential of eight housekeeping genes, i.e. β-actin (ACTB), ribosomal protein L17 (RPL17), α-tubulin (TUBA), elongation factor-1-α(EF1A), β-2-Microglobulin (B2M), RNA polymerase II subunit D (RPSD), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and 18S ribosomal RNA (18S rRNA), as internal standards for qRT-PCR analysis of gene expression in turbot as a function of bacterial infection. For this purpose, the expression of the eight housekeeping genes in seven turbot tissues was determined by qRT-PCR before and after bacterial challenge, and the data were analyzed with the geNorm and NormFinder algorisms. The results showed that the expression of all the examined genes exhibited tissue-dependent variations both before and after bacterial challenge. Before bacterial challenge, geNorm and NormFinder identified RPSD as the gene that showed least tissue specific expression. At 12 h post-bacterial infection, geNorm ranked ACTB/GAPDH, 18S rRNA/ACTB, ACTB/GAPDH, 18S rRNA/ACTB, RPL17/TUBA, RPSD/GAPDH, and RPSD/B2M, respectively, as the most stably expressed genes in liver, spleen, kidney, gill, heart, muscle, and brain. Comparable ranking orders were produced by NormFinder. Similar results were obtained at 24 h post-bacterial infection. Taken together, these results indicate that RPSD is the most stable gene across tissue types under normal physiological conditions and that, during bacterial infection, ACTB might be used as an internal standard for the normalization of gene expression in immune relevant organs; however, no single gene or single pair of genes in the examined set of housekeeping genes can serve as a universal reference across all

Alaska Volcano Observatory

USGS Publications Warehouse

Venezky, Dina Y.; Murray, Tom; Read, Cyrus

2008-01-01

Steam plume from the 2006 eruption of Augustine volcano in Cook Inlet, Alaska. Explosive ash-producing eruptions from Alaska's 40+ historically active volcanoes pose hazards to aviation, including commercial aircraft flying the busy North Pacific routes between North America and Asia. The Alaska Volcano Observatory (AVO) monitors these volcanoes to provide forecasts of eruptive activity. AVO is a joint program of the U.S. Geological Survey (USGS), the Geophysical Institute of the University of Alaska Fairbanks (UAFGI), and the State of Alaska Division of Geological and Geophysical Surveys (ADGGS). AVO is one of five USGS Volcano Hazards Program observatories that monitor U.S. volcanoes for science and public safety. Learn more about Augustine volcano and AVO at http://www.avo.alaska.edu.

Radiation Climatology of the Greenland Ice Sheet Derived from Greenland Climate Network Data

NASA Technical Reports Server (NTRS)

Steffen, Konrad; Box, Jason

2003-01-01

The magnitude of shortwave and longwave dative fluxes are critical to surface energy balance variations over the Greenland ice sheet, affecting many aspects of its climate, including melt rates, the nature of low-level temperature inversions, the katabatic wind regime and buoyant stability of the atmosphere. Nevertheless, reliable measurements of the radiative fluxes over the ice sheet are few in number, and have been of limited duration and areal distribution (e.g. Ambach, 1960; 1963, Konzelmann et al., 1994, Harding et al., 1995, Van den Broeke, 1996). Hourly GC-Net radiation flux measurements spanning 1995-2001 period have been used to produce a monthly dataset of surface radiation balance components. The measurements are distributed widely across Greenland and incorporate multiple sensors

Winter Camp: A Blog from the Greenland Summit

NASA Technical Reports Server (NTRS)

Koenig, Lora

2009-01-01

This article presents the first half of the author's experience living and working at the National Science Foundation's (NSF) Greenland Summit Camp. The author is a remote-sensing glaciologist at NASA's Goddard Space Flight Center. She took measurements that will be used to validate data collected by NASA s Aqua, Terra, and Ice, Clouds, and land Elevation Satellite (ICESat) satellites with ground-truth measurements of the Greenland Ice Sheet she made at Summit Camp from November 2008-February 2009. This article presents excerpts from the second half of her stay and work at the Greenland Summit. The second half of the story is presented in another issue of this journal

Resident, State of Alaska

Science.gov Websites

Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees State of Alaska Search Home Quick Links Departments Commissioners Employee Whitepages State Government Jobs Federal Jobs Starting a Small Business Living Get a Driver License Get a Hunting

Visitor, State of Alaska

Science.gov Websites

Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees State of Alaska Search Home Quick Links Departments Commissioners Employee Whitepages State Government Jobs Federal Jobs Starting a Small Business Living Get a Driver License Get a Hunting

A moderate resolution inventory of small glaciers and ice caps surrounding Greenland and the Antarctic peninsula

NASA Astrophysics Data System (ADS)

Chen, C.; Box, J. E.; Hock, R. M.; Cogley, J. G.

2011-12-01

Current estimates of global Mountain Glacier and Ice Caps (MG&IC) mass changes are subject to large uncertainties due to incomplete inventories and uncertainties in land surface classification. This presentation features mitigative efforts through the creation of a MODIS dependent land ice classification system and its application for glacier inventory. Estimates of total area of mountain glaciers [IPCC, 2007] and ice caps (including those in Greenland and Antarctica) vary 15%, that is, 680 - 785 10e3 sq. km. To date only an estimated 40% of glaciers (by area) is inventoried in the World Glacier Inventory (WGI) and made available through the World Glacier Monitoring System (WGMS) and the National Snow and Ice Data Center [NSIDC, 1999]. Cogley [2009] recently compiled a more complete version of WGI, called WGI-XF, containing records for just over 131,000 glaciers, covering approximately half of the estimated global MG&IC area. The glaciers isolated from the conterminous Antarctic and Greenland ice sheets remain incompletely inventoried in WGI-XF but have been estimated to contribute 35% to the MG&IC sea-level equivalent during 1961-2004 [Hock et al., 2009]. Together with Arctic Canada and Alaska these regions alone make up almost 90% of the area that is missing in the global WGI-XF inventory. Global mass balance projections tend to exclude ice masses in Greenland and Antarctica due to the paucity of data with respect to basic inventory base data such as area, number of glaciers or size distributions. We address the need for an accurate Greenland and Antarctic peninsula land surface classification with a novel glacier surface classification and inventory based on NASA Moderate Resolution Imaging Spectroradiometer (MODIS) data gridded at 250 m pixel resolution. The presentation includes a sensitivity analysis for surface mass balance as it depends on the land surface classification. Works Cited +Cogley, J. G. (2009), A more complete version of the World Glacier

Exploring Greenland: science and technology in Cold War settings.

PubMed

Heymann, Matthias; Knudsen, Henrik; Lolck, Maiken L; Nielsen, Henry; Nielsen, Kristian H; Ries, Christopher J

2010-01-01

This paper explores a vacant spot in the Cold War history of science: the development of research activities in the physical environmental sciences and in nuclear science and technology in Greenland. In the post-war period, scientific exploration of the polar areas became a strategically important element in American and Soviet defence policy. Particularly geophysical fields like meteorology, geology, seismology, oceanography, and others profited greatly from military interest. While Denmark maintained formal sovereignty over Greenland, research activities were strongly dominated by U.S. military interests. This paper sets out to summarize the limited current state of knowledge about activities in the environmental physical sciences in Greenland and their entanglement with military, geopolitical, and colonial interests of both the USA and Denmark. We describe geophysical research in the Cold War in Greenland as a multidimensional colonial endeavour. In a period of decolonization after World War II, Greenland, being a Danish colony, became additionally colonized by the American military. Concurrently, in a period of emerging scientific internationalism, the U.S. military "colonized" geophysical research in the Arctic, which increasingly became subject to military directions, culture, and rules.

Conservation genetics of high-arctic Gull species at risk: I. Diversity in the mtDNA control region of circumpolar populations of the Endangered Ivory Gull (Pagophila eburnea).

PubMed

Royston, Stephanie R; Carr, Steven M

2016-11-01

The high-arctic Ivory Gull (Pagophila eburnea) has recently undergone a sharp decline in numbers, and in Canada it is listed as "Endangered" under the Species-At-Risk Act. To test for circumpolar genetic distinctiveness, we examined 264 bp of the mtDNA Control Region Domain I from 127 museum specimens collected during the breeding season from northern Canada, Greenland, and Norway, and during the non-breeding season from adjacent overwintering grounds in Canada, Greenland, and a disjunct area in Alaska adjacent to the Bering Sea. Partition of genetic variance according to various phylogeographic and breeding ground models indicates no strong population structure, except that Alaska birds are consistently differentiated from other locations, and there are significant temporal shifts in haplotype frequencies. The evidence suggests that Ivory Gulls in Canada, Greenland, and Norway are a single genetic entity, in contrast to Alaska birds, which may represent a distinctive Siberian population.

Influence of immunostimulant polysaccharides, nucleic acids, and Bacillus strains on the innate immune and acute stress response in turbots (Scophthalmus maximus) fed soy bean- and wheat-based diets.

PubMed

Fuchs, V I; Schmidt, J; Slater, M J; Buck, B H; Steinhagen, D

2017-12-01

Immunostimulants are widely applied in aquaculture practice and may have beneficial effects on the immune system and physical functions allowing higher tolerance to stress. In the current study, the impact of four (i-iv) dietary active ingredients on the immune and stress response of turbot was examined in two experiments (I and II). A basal low fish meal (FM; 32%) diet was formulated and supplemented with (i) yeast β-glucan and mannan oligosaccharide (GM), (ii) alginic acid (AC), (iii) yeast nucleotides and RNA (NR), or (iv) Bacillus strains (BS). The basal diet (C-LF) and a high FM (59%) control (C-HF) were maintained. All six diets were fed to juvenile turbots for 84 days in experiment I and for additional 28 days prior to experiment II. Immunological and hematological parameters were determined in experiment I. In experiment II, physical stress response to a typical short-term (<1 day) aquaculture handling procedure (combination of capture, netting/transfer, and crowding) was investigated. For this, turbot blood was sampled before and at 0.5, 1, 4, and 24 h post stress. Plasma lysozyme activity, neutrophil reactive oxygen species (ROS) production, and total plasma protein levels did not significantly differ between treatment groups; however, plasma cholesterol increased significantly in fish fed GM, AC, NR, and C-HF compared to C-LF (I). A significant increase in plasma glucose and triglyceride was observed in GM and NR treatments, while glucose levels were significantly higher in C-HF compared to C-LF. Moreover, the immunostimulant-supplemented diets exhibited significantly lower cortisol levels compared to controls C-LF (at 0.5 h) and C-HF (at 1 h) post stress, respectively (II). According to our findings, FM substitution did not modulate the innate immune response but was associated with reduced levels of cholesterol. Dietary immunostimulants were not effective enough to boost the immune response, but we believe they might be helpful to trigger

Greenland and Its Strategic Importance (Groenland und Seine Strategische Bedeutung),

DTIC Science & Technology

1983-12-22

Common Market assistance. At most places there is now electricty and piped water. The harbor facilities have been expanded, Two airports - S~ndre...occurred inter al. by the fact that for Greenland exports, regardless of the fluctuation of the market price, rather stable prices were paid and...European Common Market . In Greenland the vote was 2.5 : I against entry into the ECM, but since Greenland is an integral part of the Danish state, it

Alcohol in Greenland 1951-2010: consumption, mortality, prices.

PubMed

Aage, Hans

2012-01-01

Fluctuations in alcohol consumption in Greenland have been extreme since alcohol became available to the Greenland Inuit in the 1950s, increasing from low levels in the 1950s to very high levels in the 1980s - about twice as high as alcohol consumption in Denmark. Since then, consumption has declined, and current consumption is slightly below alcohol consumption in Denmark, while alcohol prices are far above Danish prices. Description of historical trends and possible causal connections of alcohol prices, alcohol consumption and alcohol-related mortality in Greenland 1951-2010 as a background for the evaluation of the impact of various types of policy. Time series for Greenland 1951-2010 for alcohol prices, consumption and mortality are compiled, and variation and correlations are discussed in relation to various policies aimed at limiting alcohol consumption. Corresponding time series for Denmark 1906-2010 are presented for comparison. The trends in alcohol prices and consumption followed each other rather closely until the 1990s in Greenland and the 1980s in Denmark. At this time, consumption stabilised while prices decreased further, but the effect of prices upon consumption is strong, also in recent years. A trend in Greenlandic mortality similar to consumption is discernible, but not significant. Among alcohol-related deaths cirrhosis of the liver is less prevalent whilst accidents are more prevalent than in Denmark. The effect of alcohol excise taxes and rationing upon consumption is evident. The stabilisation and subsequent decline in consumption since the mid-1990s, while alcohol prices decreased persistently, does not preclude continued effects of prices. On the contrary, price effects have been neutralised by other stronger causes. Whether these are government anti-alcohol campaigns or a cultural change is not clear.

Trace element concentrations in livers of polar bears from two populations in Northern and Western Alaska.

PubMed

Kannan, Kurunthachalam; Agusa, Tetsuro; Evans, Thomas J; Tanabe, Shinsuke

2007-10-01

Concentrations of 20 trace elements (V, Cr, Mn, Co, Cu, Zn, Rb, Sr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, Hg, Tl, Pb, and Bi) were measured in livers of polar bears (Ursus maritimus) collected from Northern and Western Alaska from 1993 to 2002 to examine differences in the profiles of trace metals between the Beaufort Sea (Northern Alaska) and the Chukchi Sea (Western Alaska) subpopulations in Alaska. Among the trace elements analyzed, concentrations of Cu (50-290 microg/g, dry wt) in polar bear livers were in the higher range of values that have been reported for marine mammals. Concentrations of Hg in polar bears varied widely, from 3.5 to 99 microg/g dry wt, and the mean concentrations in polar bears were comparable to concentrations reported previously for several other species of marine mammals. Mean concentrations of Pb and Cd were 0.67 and 1.0 microg/g dry wt, respectively; these concentrations were lower than levels reported elsewhere for polar bears from Greenland and Canada. Age- and gender-related variations in the concentrations of trace elements in our polar bears were minimal. Concentrations of Hg decreased slowly in samples collected during 1993-2002, whereas Cd and Pb concentrations were found to be stable or slowly increasing, in the livers of Alaskan polar bears. Concentrations of Ag, Bi, Ba, Cu, and Sn were significantly higher in the Chukchi Sea subpopulation than in the Beaufort Sea subpopulation. Concentrations of Hg were significantly higher in the Beaufort Sea subpopulation than in the Chukchi Sea subpopulation. Differences in the profiles and concentrations of Hg, Ag, Bi, Ba, Cu, and Sn suggest that the sources of exposure to these trace elements between Western and Northern Alaskan polar bears are different, in agreement with findings reported earlier for several organic contaminants.

Characterization of household waste in Greenland

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eisted, Rasmus, E-mail: raei@env.dtu.dk; Christensen, Thomas H.

2011-07-15

The composition of household waste in Greenland was investigated for the first time. About 2 tonnes of household waste was sampled as every 7th bag collected during 1 week along the scheduled collection routes in Sisimiut, the second largest town in Greenland with about 5400 inhabitants. The collection bags were sorted manually into 10 material fractions. The household waste composition consisted primarily of biowaste (43%) and the combustible fraction (30%), including anything combustible that did not belong to other clean fractions as paper, cardboard and plastic. Paper (8%) (dominated by magazine type paper) and glass (7%) were other important materialmore » fractions of the household waste. The remaining approximately 10% constituted of steel (1.5%), aluminum (0.5%), plastic (2.4%), wood (1.0%), non-combustible waste (1.8%) and household hazardous waste (1.2%). The high content of biowaste and the low content of paper make Greenlandic waste much different from Danish household waste. The moisture content, calorific value and chemical composition (55 elements, of which 22 were below detection limits) were determined for each material fraction. These characteristics were similar to what has been found for material fractions in Danish household waste. The chemical composition and the calorific value of the plastic fraction revealed that this fraction was not clean but contained a lot of biowaste. The established waste composition is useful in assessing alternative waste management schemes for household waste in Greenland.« less

Alaska Seismic Hazards Safety Commission

Science.gov Websites

State Employees ASHSC State of Alaska search Alaska Seismic Hazards Safety Commission View of Anchorage and Commissions Alaska Seismic Hazards Safety Commission (ASHSC) main contant Alaska Seismic Hazards Safety Commission logo Alaska Seismic Hazards Safety Commission (ASHSC) - Mission The Alaska Seismic

Otitis media in Greenland. Studies on historical, epidemiological, microbiological, and immunological aspects.

PubMed

Homøe, P

2001-01-01

This thesis describes the different aspects of otitis media (OM) in the population of Greenland viewed in a historical and modern clinical perspective. Chapter 1 outlines the addressed problems and aims while chapters 2 and 3 deal with historical studies and an evaluation of the present knowledge based on the literature. Physical anthropological studies, using skeletal samples of adult Eskimo crania from before and after the colonization of Greenland in 1721 and information about modern living Eskimos (Inuit), have shown that OM sequelae of the temporal bones were significantly less common in pre-colonization Eskimos and that the mean area size of the pneumatized cell system in the temporal bone was significantly larger in pre-colonization Eskimos. These findings indicated an increase in OM after the colonization most likely caused by the social, cultural, habitary, and dietary changes due to increased contact with the outside world. Historical reports after the colonization confirm a high prevalence of OM especially in children. Modern epidemiological studies from the 1960's to 1980's in the Arctic region of Alaska, Canada, and Greenland along with reports from visiting consultant otologists in Greenland almost uniformly mention prevalent OM problems in children as well as in adults. The aim was therefore to further describe the epidemiological pattern of the different OM disease entities (acute OM (AOM), chronic OM (COM), COM with suppuration (CSOM), secretory OM (SOM), and cholesteatoma) and investigate the potentially associated risk factors in especially Greenlandic children because these diseases are primarily established and problematical in childhood. Chapter 4 describes the definitions used in the thesis and chapter 5 describes the studies included. Section 5.1 describes a study of cholesteatoma in Greenlanders. The study revealed an almost similar incidence of hospital treated children with cholesteatoma (6.6 per 100,000) as seen in comparable studies

Glacial Earthquakes: Monitoring Greenland's Glaciers Using Broadband Seismic Data

NASA Astrophysics Data System (ADS)

Olsen, K.; Nettles, M.

2017-12-01

The Greenland ice sheet currently loses 400 Gt of ice per year, and up to half of that mass loss comes from icebergs calving from marine-terminating glaciers (Enderlin et al., 2014). Some of the largest icebergs produced by Greenland's glaciers generate magnitude 5 seismic signals when they calve. These glacial earthquakes are recorded by seismic stations around the world. Full-waveform inversion and analysis of glacial earthquakes provides a low-cost tool to identify where and when gigaton-sized icebergs calve, and to track this important mass-loss mechanism in near-real-time. Fifteen glaciers in Greenland are known to have produced glacial earthquakes, and the annual number of these events has increased by a factor of six over the past two decades (e.g., Ekström et al., 2006; Olsen and Nettles, 2017). Since 2000, the number of glacial earthquakes on Greenland's west coast has increased dramatically. Our analysis of three recent years of data shows that more glacial earthquakes occurred on Greenland's west coast from 2011 - 2013 than ever before. In some cases, glacial-earthquake force orientations allow us to identify which section of a glacier terminus produced the iceberg associated with a particular event. We are able to track the timing of major changes in calving-front orientation at several glaciers around Greenland, as well as progressive failure along a single calving front over the course of hours to days. Additionally, the presence of glacial earthquakes resolves a glacier's grounded state, as glacial earthquakes occur only when a glacier terminates close to its grounding line.

Evidence of Influence of Human Activities and Volcanic Eruptions on Environmental Perchlorate from a 300-Year Greenland Ice Core Record.

PubMed

Cole-Dai, Jihong; Peterson, Kari Marie; Kennedy, Joshua Andrew; Cox, Thomas S; Ferris, David G

2018-06-26

A 300-year (1700-2007) chronological record of environmental perchlorate, reconstructed from high-resolution analysis of a central Greenland ice core, shows that perchlorate levels in the post-1980 atmosphere were two-to-three times those of the pre-1980 environment. While this confirms recent reports of increased perchlorate in Arctic snow since 1980 compared with the levels for the prior decades (1930-1980), the longer Greenland record demonstrates that the Industrial Revolution and other human activities, which emitted large quantities of pollutants and contaminants, did not significantly impact environmental perchlorate, as perchlorate levels remained stable throughout the eighteenth, nineteenth, and much of the twentieth centuries. The increased levels since 1980 likely result from enhanced atmospheric perchlorate production, rather than from direct release from perchlorate manufacturing and applications. The enhancement is probably influenced by the emission of organic chlorine compounds in the last several decades. Prior to 1980, no significant long-term temporal trends in perchlorate concentration are observed. Brief (a few years) high concentration episodes appear frequently over an apparently stable and low background (~1 ng kg‒1). Several such episodes coincide in time with large explosive volcanic eruptions including the 1912 Novarupta/Katmai eruption in Alaska. It appears that atmospheric perchlorate production is impacted by large eruptions in both high and low latitudes, but not by small eruptions and non-explosive degassing.

Alaska exceptionality hypothesis: Is Alaska wilderness really different?

Treesearch

Gregory Brown

2002-01-01

The common idiom of Alaska as “The Last Frontier” suggests that the relative remoteness and unsettled character of Alaska create a unique Alaskan identity, one that is both a “frontier” and the “last” of its kind. The frontier idiom portrays the place and people of Alaska as exceptional or different from the places and people who reside in the Lower Forty- Eight States...

Climate Change and Baleen Whale Trophic Cascades in Greenland

DTIC Science & Technology

2009-09-30

DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited. Climate Change and Baleen Whale Trophic Cascades in Greenland...SUBTITLE Climate Change And Baleen Whale Trophic Cascades In Greenland 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S

Contrasting temperature trends across the ice-free part of Greenland.

PubMed

Westergaard-Nielsen, Andreas; Karami, Mojtaba; Hansen, Birger Ulf; Westermann, Sebastian; Elberling, Bo

2018-01-25

Temperature changes in the Arctic have notable impacts on ecosystem structure and functioning, on soil carbon dynamics, and on the stability of permafrost, thus affecting ecosystem functions and putting man-built infrastructure at risk. Future warming in the Arctic could accelerate important feedbacks in permafrost degradation processes. Therefore it is important to map vulnerable areas most likely to be impacted by temperature changes and at higher risk of degradation, particularly near communities, to assist adaptation to climate change. Currently, these areas are poorly assessed, especially in Greenland. Here we quantify trends in satellite-derived land surface temperatures and modelled air temperatures, validated against observations, across the entire ice-free Greenland. Focus is on the past 30 years, to characterize significant changes and potentially vulnerable regions at a 1 km resolution. We show that recent temperature trends in Greenland vary significantly between seasons and regions and that data with resolutions down to single km 2 are critical to map temperature changes for guidance of further local studies and decision-making. Only a fraction of the ice-free Greenland seems vulnerable due to warming when analyzing year 2001-2015, but the most pronounced changes are found in the most populated parts of Greenland. As Greenland represents important gradients of north/south coast/inland/distance to large ice sheets, the conclusions are also relevant in an upscaling to greater Arctic areas.

Holocene relative sea level changes in Greenland: a review

NASA Astrophysics Data System (ADS)

Bennike, O.

2010-12-01

During the Holocene marked relative sea-level changes have taken place in the ice-free parts of Greenland. Already in 1776 it was reported that Thule winter houses and Norse ruins were partly inundated by the sea, and in 1962 the first emergence curve from Greenland was published. This has been followed by reconstruction of many other emergence curves. During the last ice age, large volumes of water were stored in the ice sheets. When the ice melted global sea level rose. In Greenland the ice sheet shrank in size, and the following emergence of the land surpassed the global sea level rise. Raised beach ridges, deltas and marine deposits are widespread in Greenland, and the uppermost form the marine limit, above which fresh-looking till deposits and perched boulders can be found. The marine limit has been mapped at numerous sites in Greenland, and the highest is at about 140 metres above the present sea level. In general, the marine limit is highest in those areas that were released from the largest load of ice. In other Arctic regions, well-constrained sea level curves have been constructed from dated drift-wood samples or whale bones from raised beaches. However, both driftwood and whale bones are rare in Greenland, and most curves have been developed from dated shells of bivalves. In the past years, isolation basins have increasingly been used to reconstruct sea level changes after the last deglaciation. Isolation basins are formed when the threshold of marine basins are lifted up above sea level. The use of this method requires that a series of lakes can be sampled at different elevations below the marine limit. Sampling of marine basins in shallow waters has also shown that many lakes have been inundated by the sea, and by dating the transgression horizons in the sediment sequences and by determining the depth of the sill, it is possible to work out curves for relative sea level rises during the past millennia. The global sea level has been fairly stable during

Alaska telemedicine: growth through collaboration.

PubMed

Patricoski, Chris

2004-12-01

The last thirty years have brought the introduction and expansion of telecommunications to rural and remote Alaska. The intellectual and financial investment of earlier projects, the more recent AFHCAN Project and the Universal Service Administrative Company Rural Health Care Division (RHCD) has sparked a new era in telemedicine and telecommunication across Alaska. This spark has been flamed by the dedication and collaboration of leaders at he highest levels of organizations such as: AFHCAN member organizations, AFHCAN Office, Alaska Clinical Engineering Services, Alaska Federal Health Care Partnership, Alaska Federal Health Care Partnership Office, Alaska Native health Board, Alaska Native Tribal health Consortium, Alaska Telehealth Advisory Council, AT&T Alascom, GCI Inc., Health care providers throughout the state of Alaska, Indian Health Service, U.S. Department of Health and Human Services, Office of U.S. Senator Ted Steens, State of Alaska, U.S. Department of Homeland Security--United States Coast Guard, United States Department of Agriculture, United States Department of Defense--Air Force and Army, United States Department of Veterans Affairs, University of Alaska, and University of Alaska Anchorage. Alaska now has one of the largest telemedicine programs in the world. As Alaska moves system now in place become self-sustaining, and 2) collaborating with all stakeholders in promoting the growth of an integrated, state-wide telemedicine network.

Towards Greenland Glaciation: cumulative or abrupt transition?

NASA Astrophysics Data System (ADS)

Ramstein, Gilles; Tan, Ning; Ladant, Jean-baptiste; Dumas, Christophe; Contoux, Camille

2017-04-01

During the mid-Pliocene warming period (3-3.3 Ma BP), the global annual mean temperatures inferred by data and model studies were 2-3° warmer than pre-industrial values. Accordingly, Greenland ice sheet volume is supposed to reach at the most, only half of that of present-day [Haywood et al. 2010]. Around 2.7-2.6 Ma BP, just ˜ 500 kyr after the warming peak of mid-Pliocene, the Greenland ice sheet has reached its full size [Lunt et al. 2008]. A crucial question concerns the evolution of the Greenland ice sheet from half to full size during the 3 - 2.5 Ma period. Data show a decreasing trend of atmospheric CO2 concentration from 3 Ma to 2.5 Ma [Seki et al.2010; Bartoli et al. 2011; Martinez et al. 2015]. However, a recent study [Contoux et al. 2015] suggests that a lowering of CO2 is not sufficient to initiate a perennial glaciation on Greenland and must be combined with low summer insolation to preserve the ice sheet during insolation maxima. This suggests rather a cumulative process than an abrupt event. In order to diagnose the evolution of the ice sheet build-up, we carry on, for the first time, a transient simulation of climate and ice sheet evolutions from 3 Ma to 2.5 Ma. This strategy enables us to investigate the waxing and waning of the ice sheet during several orbital cycles. We use a tri-dimensional interpolation method designed by Ladant et al. (2014), which allows the evolution of CO2 concentration and of orbital parameters, and the evolution of the Greenland ice sheet size to be taken into account. By interpolating climatic snapshot simulations ran with various possible combinations of CO2, orbits and ice sheet sizes, we can build a continuous climatic forcing that is then used to provide 500 kyrs-long ice sheet simulations. With such a tool, we may offer a physically based answer to different CO2 reconstructions scenarios and analyse which one is the most consistent with Greenland ice sheet buildup.

Assessment of Glacial Isostatic Adjustment in Greenland using GPS

NASA Astrophysics Data System (ADS)

Khan, S. A.; Bevis, M. G.; Sasgen, I.; van Dam, T. M.; Wahr, J. M.; Wouters, B.; Bamber, J. L.; Willis, M. J.; Knudsen, P.; Helm, V.; Kuipers Munneke, P.; Muresan, I. S.

2015-12-01

The Greenland GPS network (GNET) was constructed to provide a new means to assess viscoelastic and elastic adjustments driven by past and present-day changes in ice mass. Here we assess existing glacial isostatic adjustments (GIA) predictions by analysing 1995-2015 data from 61 continuous GPS receivers located along the margin of the Greenland ice sheet. Since GPS receivers measure both the GIA and elastic signals, we isolate GIA, by removing the elastic adjustments of the lithosphere due to present-day mass changes using high-resolution fields of ice surface elevation change derived from satellite and airborne altimetry measurements (ERS1/2, ICESat, ATM, ENVISAT, and CryoSat-2). For most GPS stations, our observed GIA rates contradict GIA predictions; particularly, we find huge uplift rates in southeast Greenland of up to 14 mm/yr while models predict rates of 0-2 mm/yr. Our results suggest possible improvements of GIA predictions, and hence of the poorly constrained ice load history and Earth structure models for Greenland.

Greenland's Biggest Losers

NASA Astrophysics Data System (ADS)

Box, J. E.; Hubbard, A.; Howat, I. M.; Csatho, B. M.; Decker, D. T.; Bates, R.; Tulaczyk, S. M.

2010-12-01

On 4 August, 2010, 275 square km of the front of the floating Petermann Glacier, far northwest Greenland, broke away. The glacier effectively retreated 15 km. Petermann has retreated 21 km since year 2000. Consulting available imagery, publications, and maps spanning the past century, we conclude that this is a retreat to a minimum extent in the observational record. This glacier is not the only ice are loser in Greenland. GRACE observations verify the concern of increased mass budget deficit. Retreat is ongoing at the 110 km wide Humboldt glacier and at the 23 km wide Zachariae ice stream. Humboldt, Zachariae, and Petermann (16 km wide) are among a handful of large marine-terminating outlets that have bedrock trenches that lead inland below sea level to the thick, interior reservoir of the ice sheet. Sleeping giants are awakening. Our area change survey of the 35 widest Greenland outlets indicates an annual marine-terminating glacier area loss rate in excess of 130 sq km per year. Here, we evaluate in this context the mechanisms for marine-terminating glacier retreat, dynamical responses to calving, and the apparent climate forcings. The work thus consults a suite of data sets, including: long-term meteorological station records; satellite-derived sea and land surface temperatures; satellite-derived sea ice extent; regional climate model output; oceanographic casts; time lapse cameras, surface elevation change, and tidal records. Cumulative area change at Greenland’s glacier top 5 “losers”. 2010 areas are measured ~1 month prior to the end of summer melt when the survey usually is made . We do not expect 2010 area changes to be much different using the future data. If anything, we expect the losses to be larger. Click here for a full resolution graphic.

One million years of glaciation and denudation history in west Greenland

PubMed Central

Strunk, Astrid; Knudsen, Mads Faurschou; Egholm, David L.; Jansen, John D.; Levy, Laura B.; Jacobsen, Bo H.; Larsen, Nicolaj K.

2017-01-01

The influence of major Quaternary climatic changes on growth and decay of the Greenland Ice Sheet, and associated erosional impact on the landscapes, is virtually unknown beyond the last deglaciation. Here we quantify exposure and denudation histories in west Greenland by applying a novel Markov-Chain Monte Carlo modelling approach to all available paired cosmogenic 10Be-26Al bedrock data from Greenland. We find that long-term denudation rates in west Greenland range from >50 m Myr−1 in low-lying areas to ∼2 m Myr−1 at high elevations, hereby quantifying systematic variations in denudation rate among different glacial landforms caused by variations in ice thickness across the landscape. We furthermore show that the present day ice-free areas only were ice covered ca. 45% of the past 1 million years, and even less at high-elevation sites, implying that the Greenland Ice Sheet for much of the time was of similar size or even smaller than today. PMID:28098141

78 FR 53137 - Flint Hills Resources Alaska, LLC, BP Pipelines (Alaska) Inc., ConocoPhillips Transportation...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-28

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket Nos. OR13-31-000] Flint Hills Resources Alaska, LLC, BP Pipelines (Alaska) Inc., ConocoPhillips Transportation Alaska, Inc., ExxonMobil... (Alaska) Inc., ConocoPhillips Transportation Alaska, Inc., and ExxonMobil Pipeline Company (collectively...

A Resilient Greenland Ice Sheet More Than 900,000 Years Old.

NASA Astrophysics Data System (ADS)

Dahl-Jensen, D.; Funder, S.; Schmidt, A. Z. M.; Solgaard, A.; Steffensen, J. P.; Willerslev, E.

2014-12-01

The Greenland Ice Sheet (GRIS) has the potential of causing a 7.36 m global sea level rise (GSLR) if it were to melt away. To properly assess risk of future melting, it is crucial to understand the formation and growth of the GRIS during past climate regimes. However, despite decades of research, it remains debated when and in what environment GRIS got established and to what extent GRIS changed in size during past warm interglacials, such as MIS 5e some 130 kyr BP. Here, we present results from analyses of environmental DNA, 10Be/36Cl, 234U/238U, single grain optically stimulated luminescence (OSL), palaeomagnetics, macrofossils and molecular clock dating of basal ice from the Camp Century ice core in north western Greenland and the Kap København Formation in North Greenland. We combine these with results from the DYE 3 and GRIP ice cores from southern and central Greenland to evaluate the evolution of the GRIS. We find evidence that the present GRIS formed quickly some time before 900 kyr BP in a largely forested Greenland and that it has changed by only 30-40% of its present volume since it was established. Our DNA findings of boreal forest imply that warming of more than 10oC is needed to have an ice-free Greenland. This threshold is higher than earlier predictions and the corresponding palaeo-calibration of the GRIS contribution to sea level changes suggests a sensitivity of 0.3-0.5 m GSLR per degree Celsius of warming over Greenland. Ice core data from the deep Greenland ice cores can be used to reconstruct the size of the ice sheet during the present interglacial (the Holocene) and the last interglacial (the Eemian). Reconstructions based on stable water isotopes and gas content is used to validate the resilience of the GRIS.

Greenland Ice Sheet: High-Elevation Balance and Peripheral Thinning.

PubMed

Krabill; Abdalati; Frederick; Manizade; Martin; Sonntag; Swift; Thomas; Wright; Yungel

2000-07-21

Aircraft laser-altimeter surveys over northern Greenland in 1994 and 1999 have been coupled with previously reported data from southern Greenland to analyze the recent mass-balance of the Greenland Ice Sheet. Above 2000 meters elevation, the ice sheet is in balance on average but has some regions of local thickening or thinning. Thinning predominates at lower elevations, with rates exceeding 1 meter per year close to the coast. Interpolation of our results between flight lines indicates a net loss of about 51 cubic kilometers of ice per year from the entire ice sheet, sufficient to raise sea level by 0.13 millimeter per year-approximately 7% of the observed rise.

Growth measures among preschool-age Inuit children living in Canada and Greenland.

PubMed

Galloway, Tracey; Niclasen, Birgit V L; Muckle, Gina; Young, Kue; Egeland, Grace M

2012-12-01

The present study reports findings from a study of preschool-age Inuit children living in the Arctic regions of Canada and Greenland. We compare stature and obesity measures using cutoffs from the Centers for Disease Control and the International Obesity Task Force references. The sample is comprised of 1121 Inuit children (554 boys and 567 girls) aged 3-5 years living in Nunavut (n=376) and Nunavik (n=87), Canada, in the capital city of Nuuk, Greenland (n=86), and in Greenland's remaining towns and villages (n=572). Greenland Inuit children were significantly taller than their Canadian counterparts, with greatest height and weight observed among children from Nuuk. Overall prevalence of stunting was low with the three cutoffs yielding similar values for height-for-age z-scores. Obesity prevalence was higher among Canadian Inuit children than their Greenland counterparts. Inuit children have stature values consistent with those of the Centers for Disease Control reference and low prevalence of stunting, though geographic variability in mean stature values between Canadian and Greenlandic samples likely reflects differences in both socioeconomic status and genetic admixture. Obesity prevalence is high among both Canadian and Greenland Inuit preschoolers, with children living in the city of Nuuk exhibiting lower obesity prevalence than children living in either Nunavut or Nunavik, Canada or Greenland's towns and villages. Varying obesity prevalence may reflect varying degrees of food security in remote locations as well as the influence of stature and sitting height which have not been well studied in young Inuit children.

Eemian interglacial reconstructed from a Greenland folded ice core.

PubMed

2013-01-24

Efforts to extract a Greenland ice core with a complete record of the Eemian interglacial (130,000 to 115,000 years ago) have until now been unsuccessful. The response of the Greenland ice sheet to the warmer-than-present climate of the Eemian has thus remained unclear. Here we present the new North Greenland Eemian Ice Drilling ('NEEM') ice core and show only a modest ice-sheet response to the strong warming in the early Eemian. We reconstructed the Eemian record from folded ice using globally homogeneous parameters known from dated Greenland and Antarctic ice-core records. On the basis of water stable isotopes, NEEM surface temperatures after the onset of the Eemian (126,000 years ago) peaked at 8 ± 4 degrees Celsius above the mean of the past millennium, followed by a gradual cooling that was probably driven by the decreasing summer insolation. Between 128,000 and 122,000 years ago, the thickness of the northwest Greenland ice sheet decreased by 400 ± 250 metres, reaching surface elevations 122,000 years ago of 130 ± 300 metres lower than the present. Extensive surface melt occurred at the NEEM site during the Eemian, a phenomenon witnessed when melt layers formed again at NEEM during the exceptional heat of July 2012. With additional warming, surface melt might become more common in the future.

Alaska Energy Inventory Project: Consolidating Alaska's Energy Resources

NASA Astrophysics Data System (ADS)

Papp, K.; Clough, J.; Swenson, R.; Crimp, P.; Hanson, D.; Parker, P.

2007-12-01

Alaska has considerable energy resources distributed throughout the state including conventional oil, gas, and coal, and unconventional coalbed and shalebed methane, gas hydrates, geothermal, wind, hydro, and biomass. While much of the known large oil and gas resources are concentrated on the North Slope and in the Cook Inlet regions, the other potential sources of energy are dispersed across a varied landscape from frozen tundra to coastal settings. Despite the presence of these potential energy sources, rural Alaska is mostly dependent upon diesel fuel for both electrical power generation and space heating needs. At considerable cost, large quantities of diesel fuel are transported to more than 150 roadless communities by barge or airplane and stored in large bulk fuel tank farms for winter months when electricity and heat are at peak demands. Recent increases in the price of oil have severely impacted the price of energy throughout Alaska, and especially hard hit are rural communities and remote mines that are off the road system and isolated from integrated electrical power grids. Even though the state has significant conventional gas resources in restricted areas, few communities are located near enough to these resources to directly use natural gas to meet their energy needs. To address this problem, the Alaska Energy Inventory project will (1) inventory and compile all available Alaska energy resource data suitable for electrical power generation and space heating needs including natural gas, coal, coalbed and shalebed methane, gas hydrates, geothermal, wind, hydro, and biomass and (2) identify locations or regions where the most economic energy resource or combination of energy resources can be developed to meet local needs. This data will be accessible through a user-friendly web-based interactive map, based on the Alaska Department of Natural Resources, Land Records Information Section's (LRIS) Alaska Mapper, Google Earth, and Terrago Technologies' Geo

Absolute gravimetry for monitoring geodynamics in Greenland.

NASA Astrophysics Data System (ADS)

Nielsen, E.; Strykowski, G.; Forsberg, R.

2015-12-01

Here are presented the preliminary results of the absolute gravity measurements done in Greenland by DTU Space with their A10 absolute gravimeter (the A10-019). The purpose, besides establishing and maintaining a national gravity network, is to study geodynamics.The absolute gravity measurements are juxtaposed with the permanent GNET GNSS stations. The first measurements were conducted in 2009 and a few sites have been re-visited. As of present is there a gravity value at 18 GNET sites.There are challenges in interpreting the measurements from Greenland and several signals has to be taken into account, besides the geodynamical signals originating from the changing load of the ice, there is also a clear signal of direct attraction from different masses. Here are presented the preliminary results of our measurements in Greenland and attempts explain them through modelling of the geodynamical signals and the direct attraction from the ocean and ice.

Geologic framework of the Alaska Peninsula, southwest Alaska, and the Alaska Peninsula terrane

USGS Publications Warehouse

Wilson, Frederic H.; Detterman, Robert L.; DuBois, Gregory D.

2015-01-01

The boundaries separating the Alaska Peninsula terrane from other terranes are commonly indistinct or poorly defined. A few boundaries have been defined at major faults, although the extensions of these faults are speculative through some areas. The west side of the Alaska Peninsula terrane is overlapped by Tertiary sedimentary and volcanic rocks and Quaternary deposits.

Alaskan Exemplary Program The Rural Alaska Honors Institute (RAHI) A Quarter Century of Success of Educating, Nurturing, and Retaining Alaska Native and Rural Students An International Polar Year Adventure in Barrow

NASA Astrophysics Data System (ADS)

Wartes, D.; Owens, G.

2007-12-01

RAHI, the Rural Alaska Honors Institute, began in 1983 after a series of meetings between the Alaska Federation of Natives and the University of Alaska, to discuss the retention rates of Alaska Native and rural students. RAHI is a six-week college-preparatory summer bridge program on the University of Alaska Fairbanks campus for Alaska Native and rural high school juniors and seniors. The student body is approximately 94 percent Alaska Native. RAHI students take classes that earn them seven to ten college credits, thus giving them a head start on college. Courses include: writing, study skills, desk top publishing, Alaska Native dance or swimming, and a choice of geoscience, biochemistry, math, business, rural development, or engineering. A program of rigorous academic activity combines with social, cultural, and recreational activities to make up the RAHI program of early preparation for college. Students are purposely stretched beyond their comfort levels academically and socially to prepare for the big step from home or village to a large culturally western urban campus. They are treated as honors students and are expected to meet all rigorous academic and social standards set by the program. All of this effort and activity support the principal goal of RAHI: promoting academic success for rural students in college. Over 25 years, 1,200 students have attended the program. Sixty percent of the RAHI alumni have entered four-year academic programs. Over 230 have earned a bachelors degree, twenty-nine have earned masters degrees, and seven have graduated with professional degrees (J.D., Ph.D., or M.D.), along with 110 associate degrees and certificates. In looking at the RAHI cohort, removing those students who have not been in college long enough to obtain a degree, 27.3 percent of RAHI alums have received a bachelors degree. An April 2006 report by the American Institutes for Research through the National Science Foundation found that: Rural Native students in the

Alcohol in Greenland 1951–2010: consumption, mortality, prices

PubMed Central

Aage, Hans

2012-01-01

Background Fluctuations in alcohol consumption in Greenland have been extreme since alcohol became available to the Greenland Inuit in the 1950s, increasing from low levels in the 1950s to very high levels in the 1980s – about twice as high as alcohol consumption in Denmark. Since then, consumption has declined, and current consumption is slightly below alcohol consumption in Denmark, while alcohol prices are far above Danish prices. Objective Description of historical trends and possible causal connections of alcohol prices, alcohol consumption and alcohol-related mortality in Greenland 1951–2010 as a background for the evaluation of the impact of various types of policy. Design Time series for Greenland 1951–2010 for alcohol prices, consumption and mortality are compiled, and variation and correlations are discussed in relation to various policies aimed at limiting alcohol consumption. Corresponding time series for Denmark 1906–2010 are presented for comparison. Results The trends in alcohol prices and consumption followed each other rather closely until the 1990s in Greenland and the 1980s in Denmark. At this time, consumption stabilised while prices decreased further, but the effect of prices upon consumption is strong, also in recent years. A trend in Greenlandic mortality similar to consumption is discernible, but not significant. Among alcohol-related deaths cirrhosis of the liver is less prevalent whilst accidents are more prevalent than in Denmark. Conclusions The effect of alcohol excise taxes and rationing upon consumption is evident. The stabilisation and subsequent decline in consumption since the mid-1990s, while alcohol prices decreased persistently, does not preclude continued effects of prices. On the contrary, price effects have been neutralised by other stronger causes. Whether these are government anti-alcohol campaigns or a cultural change is not clear. PMID:23256091

High export of dissolved silica from the Greenland Ice Sheet

NASA Astrophysics Data System (ADS)

Meire, L.; Meire, P.; Struyf, E.; Krawczyk, D. W.; Arendt, K. E.; Yde, J. C.; Juul Pedersen, T.; Hopwood, M. J.; Rysgaard, S.; Meysman, F. J. R.

2016-09-01

Silica is an essential element for marine life and plays a key role in the biogeochemistry of the ocean. Glacial activity stimulates rock weathering, generating dissolved silica that is exported to coastal areas along with meltwater. The magnitude of the dissolved silica export from large glacial areas such as the Greenland Ice Sheet is presently poorly quantified and not accounted for in global budgets. Here we present data from two fjord systems adjacent to the Greenland Ice Sheet which reveal a large export of dissolved silica by glacial meltwater relative to other macronutrients. Upscaled to the entire Greenland Ice Sheet, the export of dissolved silica equals 22 ± 10 Gmol Si yr-1. When the silicate-rich meltwater mixes with upwelled deep water, either inside or outside Greenland's fjords, primary production takes place at increased silicate to nitrate ratios. This likely stimulates the growth of diatoms relative to other phytoplankton groups.

MIS-11 duration key to disappearance of the Greenland ice sheet

NASA Astrophysics Data System (ADS)

Robinson, Alexander; Alvarez-Solas, Jorge; Calov, Reinhard; Ganopolski, Andrey; Montoya, Marisa

2017-07-01

Palaeo data suggest that Greenland must have been largely ice free during Marine Isotope Stage 11 (MIS-11). However, regional summer insolation anomalies were modest during this time compared to MIS-5e, when the Greenland ice sheet likely lost less volume. Thus it remains unclear how such conditions led to an almost complete disappearance of the ice sheet. Here we use transient climate-ice sheet simulations to simultaneously constrain estimates of regional temperature anomalies and Greenland's contribution to the MIS-11 sea-level highstand. We find that Greenland contributed 6.1 m (3.9-7.0 m, 95% credible interval) to sea level, ~7 kyr after the peak in regional summer temperature anomalies of 2.8 °C (2.1-3.4 °C). The moderate warming produced a mean rate of mass loss in sea-level equivalent of only around 0.4 m per kyr, which means the long duration of MIS-11 interglacial conditions around Greenland was a necessary condition for the ice sheet to disappear almost completely.

MIS-11 duration key to disappearance of the Greenland ice sheet.

PubMed

Robinson, Alexander; Alvarez-Solas, Jorge; Calov, Reinhard; Ganopolski, Andrey; Montoya, Marisa

2017-07-06

Palaeo data suggest that Greenland must have been largely ice free during Marine Isotope Stage 11 (MIS-11). However, regional summer insolation anomalies were modest during this time compared to MIS-5e, when the Greenland ice sheet likely lost less volume. Thus it remains unclear how such conditions led to an almost complete disappearance of the ice sheet. Here we use transient climate-ice sheet simulations to simultaneously constrain estimates of regional temperature anomalies and Greenland's contribution to the MIS-11 sea-level highstand. We find that Greenland contributed 6.1 m (3.9-7.0 m, 95% credible interval) to sea level, ∼7 kyr after the peak in regional summer temperature anomalies of 2.8 °C (2.1-3.4 °C). The moderate warming produced a mean rate of mass loss in sea-level equivalent of only around 0.4 m per kyr, which means the long duration of MIS-11 interglacial conditions around Greenland was a necessary condition for the ice sheet to disappear almost completely.

NASA OMG Mission Maps Sea Floor Depth off Greenland Coast

NASA Image and Video Library

2016-03-08

This image shows a region of the sea floor off the coast of northwest Greenland mapped as part of NASA Oceans Melting Greenland OMG mission. The data shown here will be used to understand the pathways by which warm water can reach glacier edges.

Winter Camp: A Blog from the Greenland Summit, Part II

NASA Technical Reports Server (NTRS)

Koenig, Lora

2009-01-01

An earlier issue presents the first half of the author's experience living and working at the National Science Foundation's (NSF) Greenland Summit Camp. The author is a remote-sensing glaciologist at NASA s Goddard Space Flight Center. She took measurements that will be used to validate data collected by NASA s Aqua, Terra, and Ice, Clouds, and land Elevation Satellite (ICESat) satellites with ground-truth measurements of the Greenland Ice Sheet she made at Summit Camp from November 2008-February 2009. This article presents excerpts from the second half of her stay and work at the Greenland Summit.

High-resolution Greenland ice core data show abrupt climate change happens in few years.

PubMed

Steffensen, Jørgen Peder; Andersen, Katrine K; Bigler, Matthias; Clausen, Henrik B; Dahl-Jensen, Dorthe; Fischer, Hubertus; Goto-Azuma, Kumiko; Hansson, Margareta; Johnsen, Sigfús J; Jouzel, Jean; Masson-Delmotte, Valérie; Popp, Trevor; Rasmussen, Sune O; Röthlisberger, Regine; Ruth, Urs; Stauffer, Bernhard; Siggaard-Andersen, Marie-Louise; Sveinbjörnsdóttir, Arny E; Svensson, Anders; White, James W C

2008-08-01

The last two abrupt warmings at the onset of our present warm interglacial period, interrupted by the Younger Dryas cooling event, were investigated at high temporal resolution from the North Greenland Ice Core Project ice core. The deuterium excess, a proxy of Greenland precipitation moisture source, switched mode within 1 to 3 years over these transitions and initiated a more gradual change (over 50 years) of the Greenland air temperature, as recorded by stable water isotopes. The onsets of both abrupt Greenland warmings were slightly preceded by decreasing Greenland dust deposition, reflecting the wetting of Asian deserts. A northern shift of the Intertropical Convergence Zone could be the trigger of these abrupt shifts of Northern Hemisphere atmospheric circulation, resulting in changes of 2 to 4 kelvin in Greenland moisture source temperature from one year to the next.

Volcanic influence on centennial to millennial Holocene Greenland temperature change.

PubMed

Kobashi, Takuro; Menviel, Laurie; Jeltsch-Thömmes, Aurich; Vinther, Bo M; Box, Jason E; Muscheler, Raimund; Nakaegawa, Toshiyuki; Pfister, Patrik L; Döring, Michael; Leuenberger, Markus; Wanner, Heinz; Ohmura, Atsumu

2017-05-03

Solar variability has been hypothesized to be a major driver of North Atlantic millennial-scale climate variations through the Holocene along with orbitally induced insolation change. However, another important climate driver, volcanic forcing has generally been underestimated prior to the past 2,500 years partly owing to the lack of proper proxy temperature records. Here, we reconstruct seasonally unbiased and physically constrained Greenland Summit temperatures over the Holocene using argon and nitrogen isotopes within trapped air in a Greenland ice core (GISP2). We show that a series of volcanic eruptions through the Holocene played an important role in driving centennial to millennial-scale temperature changes in Greenland. The reconstructed Greenland temperature exhibits significant millennial correlations with K + and Na + ions in the GISP2 ice core (proxies for atmospheric circulation patterns), and δ 18 O of Oman and Chinese Dongge cave stalagmites (proxies for monsoon activity), indicating that the reconstructed temperature contains hemispheric signals. Climate model simulations forced with the volcanic forcing further suggest that a series of large volcanic eruptions induced hemispheric-wide centennial to millennial-scale variability through ocean/sea-ice feedbacks. Therefore, we conclude that volcanic activity played a critical role in driving centennial to millennial-scale Holocene temperature variability in Greenland and likely beyond.

Alaska GeoFORCE, A New Geologic Adventure in Alaska

NASA Astrophysics Data System (ADS)

Wartes, D.

2011-12-01

RAHI, the Rural Alaska Honors Institute is a statewide, six-week, summer college-preparatory bridge program at the University of Alaska Fairbanks for Alaska Native and rural high school juniors and seniors. A program of rigorous academic activity combines with social, cultural, and recreational activities. Students are purposely stretched beyond their comfort levels academically and socially to prepare for the big step from home or village to a large culturally western urban campus. This summer RAHI is launching a new program, GeoFORCE Alaska. This outreach initiative is designed to increase the number and diversity of students pursuing STEM degree programs and entering the future high-tech workforce. It uses Earth science as the hook because most kids get excited about dinosaurs, volcanoes and earthquakes, but it includes physics, chemistry, math, biology and other sciences. Students will be recruited, initially from the Arctic North Slope schools, in the 8th grade to begin the annual program of approximately 8 days, the summer before their 9th grade year and then remain in the program for all four years of high school. They must maintain a B or better grade average and participate in all GeoFORCE events. The carrot on the end of the stick is an exciting field event each summer. Over the four-year period, events will include trips to Fairbanks, Arizona, Oregon and the Appalachians. All trips are focused on Earth science and include a 100+ page guidebook, with tests every night culminating with a final exam. GeoFORCE Alaska is being launched by UAF in partnership with the University of Texas at Austin, which has had tremendous success with GeoFORCE Texas. GeoFORCE Alaska will be managed by UAF's long-standing Rural Alaska Honors Insitute (RAHI) that has been successfully providing intense STEM educational opportunities for Alaskan high school students for almost 30 years. The Texas program, with adjustments for differences in culture and environment, will be

Greenland Coast in Holiday Colors

NASA Image and Video Library

2003-12-23

Vibrant reds, emerald greens, brilliant whites, and pastel blues adorn this view of the area surrounding the Jakobshavn Glacier on the western coast of Greenland captured by NASA Terra spacecraft on June 18, 2003.

On the origin of multi-decadal to centennial Greenland temperature anomalies over the past 800 yr

NASA Astrophysics Data System (ADS)

Kobashi, T.; Shindell, D. T.; Kodera, K.; Box, J. E.; Nakaegawa, T.; Kawamura, K.

2012-11-01

The surface temperature of the Greenland ice sheet is among the most important climate variables for assessing how climate change may impact human societies associated with accelerating sea level rise. However, the causes of multi-decadal-to-centennial temperature changes in Greenland are not well understood, largely owing to short observational records. To examine the causes of the Greenland temperature variability, we calculated the Greenland temperature anomalies (GTA(G-NH)) over the past 800 yr by subtracting the standardised NH temperature from the standardised Greenland temperature. It decomposes the Greenland temperature variation into background climate (NH); Polar amplification; and Regional variability (GTA(G-NH)). The Central Greenland polar amplification factor as expressed by the variance ratio = Greenland/NH is 2.6 over the past 161 yr, and 3.3-4.2 over the past 800 yr. The GTA explains 31-35% of the variation of Greenland temperature in the multi-decadal-to-centennial time scale over the past 800 yr. Another orthogonal component of the Greenland and NH temperatures, GTP(G+NH) (Greenland temperature plus = standardized Greenland temperature + standardized NH temperature) exhibited the multi-decadal variations that were likely induced by large volcanic eruptions, increasing greenhouse gasses, and internal variation of climate. We found that the GTA(G-NH) has been influenced by solar-induced changes in atmospheric circulation patterns such as those produced by North Atlantic Oscillation/Arctic Oscillation (NAO/AO). Climate modelling indicates that the anomaly is also likely linked to solar-paced changes in the Atlantic meridional overturning circulation (AMOC) and to associated changes in northward oceanic heat transport.

Bathymetry and retreat of Southeast Greenland glaciers from Operation IceBridge and Ocean Melting Greenland data

NASA Astrophysics Data System (ADS)

Millan, R.; Rignot, E. J.; Morlighem, M.; Bjork, A. A.; Mouginot, J.; Wood, M.

2017-12-01

Southeast Greenland has been one of the largest contributors to ice mass loss in Greenland in part because of significant changes in glacier dynamics. The leading hypothesis for the changes in glacier dynamics is that enhanced thermal forcing from the ocean has dislodged a number of glaciers from their anchoring positions and some of them retreated rapidly along a reverse bed. The glaciers response has been observed to vary significantly from one fjord to the next, but until now there was not enough data to understand or interpret these changes. In particular, there was no data on glacier bed topography and seafloor bathymetry in the fjords. Here we present the results of new fjord mapping by the NASA Ocean Melting Greenland mission combined with a recent high-resolution airborne gravity survey by NASA Operation IceBridge. We combine these data with a reconstruction of the bed using a mass conservation approach upstream extending into the glacial fjords for the first time. In the fjord and along the ice-ocean transition, we employ a 3D inversion of gravity data to infer the bed elevation along a set of 9 survey boxes spanning south of Helheim Glacier to the southern tip of Southeast Greenland. We combine the results with an analysis of the glacier front history since the 1930's and Conductivity Temperature Depth data obtained in the fjord by OMG in 2016. The data reveals bed elevations several 100-m deeper than previously thought, for almost all the glaciers, up to 500 m for some of them. For many glaciers, the bed profiles help to completely understand the history of retreat of the glaciers. For instance, glaciers stranded on sills have been stable; glaciers on a reverse slope have retreated rapidly; and glaciers with a normal slope have retreated slowly. The mapping also helps document the extent of the marine portion of the glacier basins. In many of the fjords, we document the presence of warm, salty Atlantic Water which fuels large melt rates. We employ

Linkages between Icelandic Low position and SE Greenland winter precipitation

NASA Astrophysics Data System (ADS)

Berdahl, M.; Rennermalm, A. K.; Hammann, A. C.; Mioduszewski, J.; Hameed, S.; Tedesco, M.; Stroeve, J. C.; Mote, T. L.

2015-12-01

Greenland's largest flux of precipitation occurs in its Southeast (SE) region. An understanding of the mechanisms controlling precipitation in this region is lacking despite its disproportionate importance in the mass balance of Greenland and the consequent contributions to sea level rise. We use weather station data from the Danish Meteorological Institute to reveal the governing influences on precipitation in SE Greenland during the winter and fall. We find that precipitation in the fall is significantly correlated to the longitude of the Icelandic Low and the NAO. Winter precipitation is correlated with the strength and longitude of the Icelandic Low, as well as the NAO. We show that in years of extreme high precipitation, onshore winds dominate, thereby advecting more moisture inland. In low precipitation years, winds are more westerly, approaching the stations from land. Understanding the controls of SE Greenland precipitation will help us predict how future precipitation in this key region may change in a warming climate.

The Mitotic and Metabolic Effects of Phosphatidic Acid in the Primary Muscle Cells of Turbot (Scophthalmus maximus).

PubMed

Wang, Tingting; Wang, Xuan; Zhou, Huihui; Jiang, Haowen; Mai, Kangsen; He, Gen

2018-01-01

Searching for nutraceuticals and understanding the underlying mechanism that promote fish growth is at high demand for aquaculture industry. In this study, the modulatory effects of soy phosphatidic acids (PA) on cell proliferation, nutrient sensing, and metabolic pathways were systematically examined in primary muscle cells of turbot ( Scophthalmus maximus ). PA was found to stimulate cell proliferation and promote G1/S phase transition through activation of target of rapamycin signaling pathway. The expression of myogenic regulatory factors, including myoD and follistatin , was upregulated, while that of myogenin and myostatin was downregulated by PA. Furthermore, PA increased intracellular free amino acid levels and enhanced protein synthesis, lipogenesis, and glycolysis, while suppressed amino acid degradation and lipolysis. PA also was found to increased cellular energy production through stimulated tricarboxylic acid cycle and oxidative phosphorylation. Our results identified PA as a potential nutraceutical that stimulates muscle cell proliferation and anabolism in fish.

Sea ice in the Greenland Sea

NASA Image and Video Library

2017-12-08

As the northern hemisphere experiences the heat of summer, ice moves and melts in the Arctic waters and the far northern lands surrounding it. The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Aqua satellite captured this true-color image of sea ice off Greenland on July 16, 2015. Large chunks of melting sea ice can be seen in the sea ice off the coast, and to the south spirals of ice have been shaped by the winds and currents that move across the Greenland Sea. Along the Greenland coast, cold, fresh melt water from the glaciers flows out to the sea, as do newly calved icebergs. Frigid air from interior Greenland pushes the ice away from the shoreline, and the mixing of cold water and air allows some sea ice to be sustained even at the height of summer. According to observations from satellites, 2015 is on track to be another low year for arctic summer sea ice cover. The past ten years have included nine of the lowest ice extents on record. The annual minimum typically occurs in late August or early September. The amount of Arctic sea ice cover has been dropping as global temperatures rise. The Arctic is two to three times more sensitive to temperature changes as the Earth as a whole. Credit: NASA/GSFC/Jeff Schmaltz/MODIS Land Rapid Response Team NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Subannual layer variability in Greenland firn cores

NASA Astrophysics Data System (ADS)

Kjær, Helle Astrid; Vallelonga, Paul; Vinther, Bo; Winstrup, Mai; Simonsen, Marius; Maffezzoli, Niccoló; Jensen, Camilla Marie

2017-04-01

Ice cores are used to infer information about the past and modern techniques allow for high resolution (< cm) continuous flow analysis (CFA) of the ice. Such analysis is often used to inform on annual layers to constrain dating of ice cores, but can also be extended to provide information on sub-annual deposition patterns. In this study we use available high resolution data from multiple shallow cores around Greenland to investigate the seasonality and trends in the most often continuously measured components sodium, insoluble dust, calcium, ammonium and conductivity (or acidity) from 1800 AD to today. We evaluate the similarities and differences between the records and discuss the causes from different sources and transport to deposition and post-deposition effects over differences in measurement set up. Further we add to the array of cores already published with measurements from the newly drilled ReCAP ice core from a coastal ice cap in eastern Greenland and from a shallow core drilled at the high accumulation site at the Greenland South Dome.

Retaining Quality Teachers for Alaska.

ERIC Educational Resources Information Center

McDiarmid, G. Williamson; Larson, Eric; Hill, Alexandra

This report examines the demand for teachers, teacher turnover, and teacher education in Alaska. Surveys were conducted with school district personnel directors, directors of Alaska teacher education programs, teachers who exited Alaska schools in 2001, and rural and urban instructional aides. Alaska is facing teacher shortages, but these are…

Fisheries Education in Alaska. Conference Report. Alaska Sea Grant Report 82-4.

ERIC Educational Resources Information Center

Smoker, William W., Ed.

This conference was an attempt to have the fishing industry join the state of Alaska in building fisheries education programs. Topics addressed in papers presented at the conference include: (1) fisheries as a part of life in Alaska, addressing participation of Alaska natives in commercial fisheries and national efforts; (2) the international…

Secret Science: Exploring Cold War Greenland

NASA Astrophysics Data System (ADS)

Harper, K.

2013-12-01

During the early Cold War - from the immediate postwar period through the 1960s - the United States military carried out extensive scientific studies and pursued technological developments in Greenland. With few exceptions, most of these were classified - sometimes because new scientific knowledge was born classified, but mostly because the reasons behind the scientific explorations were. Meteorological and climatological, ionospheric, glaciological, seismological, and geological studies were among the geophysical undertakings carried out by military and civilian scientists--some in collaboration with the Danish government, and some carried out without their knowledge. This poster will present some of the results of the Exploring Greenland Project that is coming to a conclusion at Denmark's Aarhus University.

Substantial export of suspended sediment to the global oceans from glacial erosion in Greenland

NASA Astrophysics Data System (ADS)

Overeem, I.; Hudson, B. D.; Syvitski, J. P. M.; Mikkelsen, A. B.; Hasholt, B.; van den Broeke, M. R.; Noël, B. P. Y.; Morlighem, M.

2017-11-01

Limited measurements along Greenland's remote coastline hamper quantification of the sediment and associated nutrients draining the Greenland ice sheet, despite the potential influence of river-transported suspended sediment on phytoplankton blooms and carbon sequestration. Here we calibrate satellite imagery to estimate suspended sediment concentration for 160 proglacial rivers across Greenland. Combining these suspended sediment reconstructions with numerical calculations of meltwater runoff, we quantify the amount and spatial pattern of sediment export from the ice sheet. We find that, although runoff from Greenland represents only 1.1% of the Earth's freshwater flux, the Greenland ice sheet produces approximately 8% of the modern fluvial export of suspended sediment to the global ocean. Sediment loads are highly variable between rivers, consistent with observed differences in ice dynamics and thus with control by glacial erosion. Rivers that originate from deeply incised, fast-moving glacial tongues form distinct sediment-export hotspots: just 15% of Greenland's rivers transport 80% of the total sediment load of the ice sheet. We conclude that future acceleration of melt and ice sheet flow may increase sediment delivery from Greenland to its fjords and the nearby ocean.

Greenland meltwater experiments

NASA Astrophysics Data System (ADS)

Olsen, S. M.; Schmith, T.

2012-04-01

We explore the climatic response to additional Greenland Ice Sheet melting in the EC-EARTH coupled climate model. As reference runs, we use an ensemble of two simulations from 1850 to present with historic forcing. For each of these we pick the years 1935,1950 and 1965, respectively as initial conditions for perturbed experiments with an additional freshwater forcing of 0.1 Sv distributed uniformly around Greenland , a plausible value in the upper end of future Greenland ice sheet melt estimates. We find give no evidence for abrupt transitions associated with tipping points in the Atlantic overturning circulation and mid-latitude heat transport. In fact, modelled decline in overturning in response to the additional forcing does not project onto a comparable reduction in the mid latitude (36N) ocean heat transport. This result points to an ongoing watermass transformation in the subpolar region and Arctic Mediterranean as a whole and a continued thermal mode of operation of the overturning. At the northern boundary of the subpolar region (60N) the response in overturning shows a contrasting increase in intensity along with an increase in heat transport. Whereas the latter may be expected as a result of freshwater capping and subsurface warming in the subpolar region, the increased overturning at 60N is more difficult to explain. In order to assess this in more detail we have quantified the individual thermohaline exchange components of light and dense water masses across the Greenland-Scotland Ridge. We find that the intensified overturning at 60N is reflected in increased transports of light Atlantic Water to the Nordic Seas. However, the vertical, thermohalinie overturning loop is not equally strengthened. On the contrary, we model a decline in the denser parts of the outflow, the overflows in the Denmark Strait and Faroe Bank Channel and a strong increase in the polar outflow in the Denmark Strait. We observe a gradual transition from a vertical mode of operation

Lively Earthquake Activity in North-Eastern Greenland

NASA Astrophysics Data System (ADS)

Larsen, Tine B.; Dahl-Jensen, Trine; Voss, Peter H.

2016-04-01

The seismograph at the Danish military outpost, Station Nord (NOR) in North East Greenland, records many regional/local earthquakes every day. Most of these events originate at the Arctic plate boundary between the Eurasian and the North American plates. The plate boundary has a particularly active segment approximately 200 km from the seismograph. Additionally we find a seismically very active region 20-30 km from NOR on the Kronprins Christian Land peninsula. The BB seismograph at NOR was installed in 2002 and later upgraded with real-time telemetry as part of the GLISN-project. Since late 2013 data from NOR have been included in routine processing at GEUS. Phase readings on some of the older data, primarily 2002-2003, have been carried out previously in connection with other projects. As a result, phase readings for more than 6000 local events, recorded exclusively at NOR, were found in the GEUS data base. During the years 2004 to 2007 four locations were occupied by temporary BB seismographs on the North coast of Greenland as part of the Law of the Sea preparatory work. Data from these stations have not previously been analyzed for local and regional events. In this study we combine the recordings from NOR with phase readings from the temporary seismographs in Northern Greenland. The local events on Kronprins Christian Land range in magnitude from less than 2 to a 4.8 event widely recorded in the region and felt by the personnel at Station Nord on August 30, 2005. Station Nord is located in the seismically most active region of Greenland.

CNS infections in Greenland: A nationwide register-based cohort study

PubMed Central

Nordholm, Anne Christine; Søborg, Bolette; Andersson, Mikael; Hoffmann, Steen; Skinhøj, Peter; Koch, Anders

2017-01-01

Background Indigenous Arctic people suffer from high rates of infectious diseases. However, the burden of central nervous system (CNS) infections is poorly documented. This study aimed to estimate incidence rates and mortality of CNS infections among Inuits and non-Inuits in Greenland and in Denmark. Methods We conducted a nationwide cohort study using the populations of Greenland and Denmark 1990–2012. Information on CNS infection hospitalizations and pathogens was retrieved from national registries and laboratories. Incidence rates were estimated as cases per 100,000 person-years. Incidence rate ratios were calculated using log-linear Poisson-regression. Mortality was estimated using Kaplan-Meier curves and Log Rank test. Results The incidence rate of CNS infections was twice as high in Greenland (35.6 per 100,000 person years) as in Denmark (17.7 per 100,000 person years), but equally high among Inuits in Greenland and Denmark (38.2 and 35.4, respectively). Mortality from CNS infections was 2 fold higher among Inuits (10.5%) than among non-Inuits (4.8%) with a fivefold higher case fatality rate in Inuit toddlers. Conclusion Overall, Inuits living in Greenland and Denmark suffer from twice the rate of CNS infections compared with non-Inuits, and Inuit toddlers carried the highest risk of mortality. Further studies regarding risk factors such as genetic susceptibility, life style and socioeconomic factors are warranted. PMID:28158207

Alaska Mental Health Board

Science.gov Websites

State Employees Alaska Mental Health Board DHSS State of Alaska Home Divisions and Agencies Alaska Pioneer Homes Behavioral Health Office of Children's Services Office of the Commissioner Office of Substance Misuse and Addiction Prevention Finance & Management Services Health Care Services Juvenile

Publications - STATEMAP Project | Alaska Division of Geological &

Science.gov Websites

., 2008, Surficial-geologic map of the Salcha River-Pogo area, Big Delta Quadrangle, Alaska: Alaska , Engineering - geologic map, Alaska Highway corridor, Delta Junction to Dot Lake, Alaska: Alaska Division of geologic map of the Salcha River-Pogo area, Big Delta Quadrangle, Alaska: Alaska Division of Geological

Modeled Variations of Precipitation over the Greenland Ice Sheet.

NASA Astrophysics Data System (ADS)

Bromwich, David H.; Robasky, Frank M.; Keen, Richard A.; Bolzan, John F.

1993-07-01

A parameterization of the synoptic activity at 500 hPa and a simple orographic scheme are used to model the spatial and temporal variations of precipitation over the Greenland Ice Sheet for 1963-88 from analyzed geopotential height fields produced by the National Meteorological Center (NMC). Model coefficients are fitted to observed accumulation data, primarily from the summit area of the ice sheet. All major spatial characteristics of the observed accumulation distribution are reproduced apart from the orographic accumulation maximum over the northwestern coastal slopes. The modeled time-averaged total precipitation amount over Greenland is within the range of values determined by other investigators from surface-based observations. A realistic degree of interannual variability in precipitation is also simulated.A downward trend in simulated ice sheet precipitation over the 26 years is found. This is supported by a number of lines of evidence. It matches the accumulation trends during this period from ice cores drilled in south-central Greenland. The lower tropospheric specific humidifies at two south coastal radiosonde stations also decrease over this interval. A systematic shift away from Greenland and a decrease in activity of the dominant storm track are found for relatively low precipitation periods as compared to relatively high precipitation periods. This negative precipitation trend would mean that the Greenland Ice Sheet, depending on its 1963 mass balance state, has over the 1963-88 period either decreased its negative, or increased its positive, contribution to recently observed global sea level rise.Superimposed on the declining simulated precipitation rate for the entire ice sheet is a pronounced 3-5-yr periodicity. This is prominent in the observed and modeled precipitation time series from Summit, Greenland. This cycle shows some aspects in common with the Southern Oscillation.Some deficiencies in the NMC analysts were highlighted by this work. A

Brief communication: Improved simulation of the present-day Greenland firn layer (1960-2016)

NASA Astrophysics Data System (ADS)

Ligtenberg, Stefan R. M.; Kuipers Munneke, Peter; Noël, Brice P. Y.; van den Broeke, Michiel R.

2018-05-01

By providing pore space for storage or refreezing of meltwater, the Greenland ice sheet firn layer strongly modulates runoff. Correctly representing the firn layer is therefore crucial for Greenland (surface) mass balance studies. Here, we present a simulation of the Greenland firn layer with the firn model IMAU-FDM forced by the latest output of the regional climate model RACMO2, version 2.3p2. In the percolation zone, much improved agreement is found with firn density and temperature observations. A full simulation of Greenland firn at high temporal (10 days) and spatial (11 km) resolution is available for the period 1960-2016.

Export of Strongly Diluted Greenland Meltwater From a Major Glacial Fjord

NASA Astrophysics Data System (ADS)

Beaird, Nicholas L.; Straneo, Fiammetta; Jenkins, William

2018-05-01

The Greenland Ice Sheet has been, and will continue, losing mass at an accelerating rate. The influence of this anomalous meltwater discharge on the regional and large-scale ocean could be considerable but remains poorly understood. This uncertainty is in part a consequence of challenges in observing water mass transformation and meltwater spreading in coastal Greenland. Here we use tracer observations that enable unprecedented quantification of the export, mixing, and vertical distribution of meltwaters leaving one of Greenland's major glacial fjords. We find that the primarily subsurface meltwater input results in the upwelling of the deep fjord waters and an export of a meltwater/deepwater mixture that is 30 times larger than the initial meltwater release. Using these tracer data, the vertical structure of Greenland's summer meltwater export is defined for the first time showing that half the meltwater export occurs below 65 m.

Greenland Glacier Albedo Variability

NASA Technical Reports Server (NTRS)

2004-01-01

The program for Arctic Regional Climate Assessment (PARCA) is a NASA-funded project with the prime goal of addressing the mass balance of the Greenland ice sheet. Since the formal initiation of the program in 1995, there has been a significant improvement in the estimates of the mass balance of the ice sheet. Results from this program reveal that the high-elevation regions of the ice sheet are approximately in balance, but the margins are thinning. Laser surveys reveal significant thinning along 70 percent of the ice sheet periphery below 2000 m elevations, and in at least one outlet glacier, Kangerdlugssuaq in southeast Greenland, thinning has been as much as 10 m/yr. This study examines the albedo variability in four outlet glaciers to help separate out the relative contributions of surface melting versus ice dynamics to the recent mass balance changes. Analysis of AVHRR Polar Pathfinder albedo shows that at the Petermann and Jakobshavn glaciers, there has been a negative trend in albedo at the glacier terminus from 1981 to 2000, whereas the Stor+strommen and Kangerdlugssuaq glaciers show slightly positive trends in albedo. These findings are consistent with recent observations of melt extent from passive microwave data which show more melt on the western side of Greenland and slightly less on the eastern side. Significance of albedo trends will depend on where and when the albedo changes occur. Since the majority of surface melt occurs in the shallow sloping western margin of the ice sheet where the shortwave radiation dominates the energy balance in summer (e.g. Jakobshavn region) this region will be more sensitive to changes in albedo than in regions where this is not the case. Near the Jakobshavn glacier, even larger changes in albedo have been observed, with decreases as much as 20 percent per decade.

Influence of the Latitudinal Temperature Gradient on Soil Dust Concentration and Deposition in Greenland

NASA Technical Reports Server (NTRS)

Tegen, Ina; Rind, David

2000-01-01

To investigate the effects of changes in the latitudinal temperature gradient and the global mean temperature on dust concentration in the Northern Hemisphere, experiments with the Goddard Institute for Space Studies General Circulation Model (GISS GCM) are performed. The dust concentration over Greenland is calculated from sources in central and eastern Asia, which are integrated on-line in the model. The results show that an increase in the latitudinal temperature gradient increases both the Asian dust source strength and the concentration over Greenland. The source increase is the result of increased surface winds, and to a minor extent, the increase in Greenland dust is also associated with increased northward transport. Cooling the climate in addition to this increased gradient leads to a decrease in precipitation scavenging, which helps produce a further (slight) increase in Greenland dust in this experiment. Reducing the latitudinal gradient reduces the surface wind and hence the dust source, with a subsequent reduction in Greenland dust concentrations. Warming the climate in addition to this reduced gradient leads to a further reduction in Greenland dust due to enhanced precipitation scavenging. These results can be used to evaluate the relationship of Greenland ice core temperature changes to changes in the latitudinal and global temperatures.

Alaska's Economy: What's Ahead?

ERIC Educational Resources Information Center

Alaska Review of Social and Economic Conditions, 1987

1987-01-01

This review describes Alaska's economic boom of the early 1980s, the current recession, and economic projections for the 1990s. Alaska's economy is largely influenced by oil prices, since petroleum revenues make up 80% of the state government's unrestricted general fund revenues. Expansive state spending was responsible for most of Alaska's…

Cooperative Alaska Forest Inventory

Treesearch

Thomas Malone; Jingjing Liang; Edmond C. Packee

2009-01-01

The Cooperative Alaska Forest Inventory (CAFI) is a comprehensive database of boreal forest conditions and dynamics in Alaska. The CAFI consists of field-gathered information from numerous permanent sample plots distributed across interior and south-central Alaska including the Kenai Peninsula. The CAFI currently has 570 permanent sample plots on 190 sites...

greenland_summer_campaign_1

NASA Image and Video Library

2017-12-08

Laurence Smith, chair of geography at University of California, Los Angeles, deploys an autonomous drift boat equipped with several sensors in a meltwater river on the surface of the Greenland ice sheet on July 19, 2015. “Surface melting in Greenland has increased recently, and we lacked a rigorous estimate of the water volumes being produced and their transport,” said Tom Wagner, the cryosphere program scientist at NASA Headquarters in Washington. “NASA funds fieldwork like Smith’s because it helps us to interpret satellite data, and to extrapolate measurements from the local field sites to the larger ice sheet." Credit: NASA/Goddard/Jefferson Beck Read more: www.nasa.gov/feature/a-summer-of-nasa-research-on-sea-lev... NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Holocene history of North Ice Cap, northwestern Greenland

NASA Astrophysics Data System (ADS)

Corbett, L. B.; Kelly, M. A.; Osterberg, E. C.; Axford, Y.; Bigl, M.; Roy, E. P.; Thompson, J. T.

2013-12-01

Although much research has focused on the past extents of the Greenland Ice Sheet, less is known about the smaller ice caps on Greenland and how they have evolved over time. These small ice caps respond sensitively to summer temperatures and, to a lesser extent, winter precipitation, and provide valuable information about climatic conditions along the Greenland Ice Sheet margins. Here, we investigate the Holocene history of North Ice Cap (76°55'N 68°00'W), located in the Nunatarssuaq region near Thule, northwest Greenland. Our results are based on glacial geomorphic mapping, 10Be dating, and analyses of sediment cores from a glacially fed lake. Fresh, unweathered and unvegetated boulders comprise moraines and drift that mark an extent of North Ice Cap ~25 m outboard of the present ice margin. It is likely that these deposits were formed during late Holocene time and we are currently employing 10Be surface exposure dating to examine this hypothesis. Just outboard of the fresh moraines and drift, boulders and bedrock show significant weathering and are covered with lichen. Based on glacial geomorphic mapping and detailed site investigations, including stone counts, we suggest that the weathered boulders and bedrock were once covered by erosive Greenland Ice Sheet flow from southeast to northwest over the Nunatarssuaq region. Five 10Be ages from the more weathered landscape only 100-200 m outboard of the modern North Ice Cap margin are 52 and 53 ka (bedrock) and 16, 23, and 31 ka (boulders). These ages indicate that recent ice cover has likely been cold-based and non-erosive, failing to remove inherited cosmogenic nuclides from previous periods of exposure, although the youngest boulder may provide a maximum limiting deglaciation age. Sediment cores collected from Delta Sø, a glacially-fed lake ~1.5 km outside of the modern North Ice Cap margin, contain 130 cm of finely laminated sediments overlying coarse sands and glacial till. Radiocarbon ages from just above

Appellate Courts - Alaska Court System

Science.gov Websites

Court Cases Appellate Case Management System Oral Argument Supreme Court Calendar, Court of Appeals , which contains the Alaska cases excerpted from P.2d and P.3d. The Pacific Reporter or the Alaska the Alaska cases excerpted from P.2d and P.3d. The Pacific Reporter or the Alaska Reporter is

Alaska looks HOT!

DOE Office of Scientific and Technical Information (OSTI.GOV)

Belcher, J.

Production in Alaska has been sluggish in recent years, with activity in the Prudhoe Bay region in the North Slope on a steady decline. Alaska North Slope (ANS) production topped out in 1988 at 2.037 MMbo/d, with 1.6 MMbo/d from Prudhoe Bay. This year operators expect to produce 788 Mbo/d from Prudhoe Bay, falling to 739 Mbo/d next year. ANS production as a whole should reach 1.3 MMbo/d this year, sliding to 1.29 MMbo/d in 1998. These declining numbers had industry officials and politicians talking about the early death of the Trans-Alaskan Pipeline System-the vital link between ANS crude andmore » markets. But enhanced drilling technology coupled with a vastly improved relationship between the state government and industry have made development in Alaska more economical and attractive. Alaska`s Democratic Gov. Tommy Knowles is fond of telling industry {open_quotes}we`re open for business.{close_quotes} New discoveries on the North Slope and in the Cook Inlet are bringing a renewed sense of optimism to the Alaska exploration and production industry. Attempts by Congress to lift a moratorium on exploration and production activity in the Arctic National Wildlife Refuge (ANWR) have been thwarted thus far, but momentum appears to be with proponents of ANWR drilling.« less

Alaska Tidal Datum Portal | Alaska Division of Geological & Geophysical

Science.gov Websites

Engineering Geology Alaska Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Portal Unambiguous vertical datums in the coastal environment are critical to the evaluation of natural human life, property, and the coastal environment. January 2017 - Update Summary Alaska Tidal Datum

The formation of Greenland Sea Deep Water: double diffusion or deep convection?

NASA Astrophysics Data System (ADS)

Clarke, R. Allyn; Swift, James H.; Reid, Joseph L.; Koltermann, K. Peter

1990-09-01

An examination of the extensive hydrographic data sets collected by C.S.S. Hudson and F.S. Meteor in the Norwegian and Greenland Seas during February-June 1982 reveals property distributions and circulation patterns broadly similar to those seen in earlier data sets. These data sets, however, reveal the even stronger role played by topography, with evidence of separate circulation patterns and separate water masses in each of the deep basins. The high precision temperature, salinity and oxygen data obtained reveals significant differences in the deep and bottom waters found in the various basins of the Norwegian and Greenland Seas. A comparison of the 1982 data set with earlier sets shows that the renewal of Greenland Sea Deep Water must have taken place sometime over the last decade; however there is no evidence that deep convective renewal of any of the deep and bottom waters in this region was taking place at the time of the observations. The large-scale density fields, however, do suggest that deep convection to the bottom is most likely to occure in the Greenland Basin due to its deep cyclonic circulation. The hypothesis that Greenland Sea Deep Water (GSDW) is formed through dipycnal mixing processes acting on the warm salty core of Atlantic Water entering the Greenland Sea is examined. θ-S correlations and oxygen concentrations suggest that the salinity maxima in the Greenland Sea are the product of at least two separate mixing processes, not the hypothesized single mixing process leading to GSDW. A simple one-dimensional mixed layer model with ice growth and decay demonstrates that convective renewal of GSDW would have occurred within the Greenland Sea had the winter been a little more severe. The new GSDW produced would have only 0.003 less salt and less than 0.04 ml 1 -1 greater oxygen concentration than that already in the basin. Consequently, detection of whether new deep water has been produced following a winter cooling season could be difficult even

High Resolution Shear-Wave Velocity Structure of Greenland from Surface Wave Analysis

NASA Astrophysics Data System (ADS)

Pourpoint, M.; Anandakrishnan, S.; Ammon, C. J.

2016-12-01

We present a high resolution seismic tomography model of Greenland's lithosphere from the analysis of fundamental mode Rayleigh-wave group velocity dispersion measurements. Regional and teleseismic events recorded by the GLISN, GSN and CN seismic networks over the last 20 years were used. In order to better constrain the crustal structure of Greenland, we also collected and processed several years of ambient noise data. We developed a new group velocity correction method that helps to alleviate the limitations of the sparse Greenland station network and the relatively few local events. The global dispersion model GDM52 from Ekström [2011] was used to calculate group delays from the earthquake to the boundaries of our study area. An iterative reweighted generalized least-square approach was used to invert for the group velocity maps between periods of 5 s and 180 s. A Markov chain Monte Carlo technique was then applied to invert for a 3-D shear wave velocity model of Greenland up to a depth of 200 km and estimate the uncertainties in the model. Our method results in relatively uniform azimuthal coverage and high resolution length ( 200 to 400 km) in west and east Greenland. We detect a deep high velocity zone extending from northwestern to southwestern Greenland and a low velocity zone (LVZ) between central-eastern and northeastern Greenland. The location of the LVZ correlates well with a previously measured high geothermal heat flux and could provide valuable information about its source. We expect the results of the ambient noise tomography to cross-validate the earthquake tomography results and give us a better estimate of the spatial extent and amplitude of the LVZ at shallow depths. A refined regional model of Greenland's lithospheric structure should eventually help better understand how underlying geological and geophysical processes may impact the dynamics of the ice sheet and influence its potential contribution to future sea level changes.

The Mitotic and Metabolic Effects of Phosphatidic Acid in the Primary Muscle Cells of Turbot (Scophthalmus maximus)

PubMed Central

Wang, Tingting; Wang, Xuan; Zhou, Huihui; Jiang, Haowen; Mai, Kangsen; He, Gen

2018-01-01

Searching for nutraceuticals and understanding the underlying mechanism that promote fish growth is at high demand for aquaculture industry. In this study, the modulatory effects of soy phosphatidic acids (PA) on cell proliferation, nutrient sensing, and metabolic pathways were systematically examined in primary muscle cells of turbot (Scophthalmus maximus). PA was found to stimulate cell proliferation and promote G1/S phase transition through activation of target of rapamycin signaling pathway. The expression of myogenic regulatory factors, including myoD and follistatin, was upregulated, while that of myogenin and myostatin was downregulated by PA. Furthermore, PA increased intracellular free amino acid levels and enhanced protein synthesis, lipogenesis, and glycolysis, while suppressed amino acid degradation and lipolysis. PA also was found to increased cellular energy production through stimulated tricarboxylic acid cycle and oxidative phosphorylation. Our results identified PA as a potential nutraceutical that stimulates muscle cell proliferation and anabolism in fish. PMID:29780359

Alaska Job Center Network

Science.gov Websites

Job Centers Toll-free in Alaska (877)724-2539 *Workshop Schedules are linked under participating Job : midtown.jobcenter@alaska.gov Employers: anchorage.employers@alaska.gov Toll free Anchorage Employer Phone: 1-888-830 -1149 Phone: 842-5579 Fax: 842-5679, Toll Free: 1-800-478-5579 Job Seekers & Employers

Greenland ice sheet motion insensitive to exceptional meltwater forcing.

PubMed

Tedstone, Andrew J; Nienow, Peter W; Sole, Andrew J; Mair, Douglas W F; Cowton, Thomas R; Bartholomew, Ian D; King, Matt A

2013-12-03

Changes to the dynamics of the Greenland ice sheet can be forced by various mechanisms including surface-melt-induced ice acceleration and oceanic forcing of marine-terminating glaciers. We use observations of ice motion to examine the surface melt-induced dynamic response of a land-terminating outlet glacier in southwest Greenland to the exceptional melting observed in 2012. During summer, meltwater generated on the Greenland ice sheet surface accesses the ice sheet bed, lubricating basal motion and resulting in periods of faster ice flow. However, the net impact of varying meltwater volumes upon seasonal and annual ice flow, and thus sea level rise, remains unclear. We show that two extreme melt events (98.6% of the Greenland ice sheet surface experienced melting on July 12, the most significant melt event since 1889, and 79.2% on July 29) and summer ice sheet runoff ~3.9 σ above the 1958-2011 mean resulted in enhanced summer ice motion relative to the average melt year of 2009. However, despite record summer melting, subsequent reduced winter ice motion resulted in 6% less net annual ice motion in 2012 than in 2009. Our findings suggest that surface melt-induced acceleration of land-terminating regions of the ice sheet will remain insignificant even under extreme melting scenarios.

Audit report from Greenland on nurses' tasks and perceived competency.

PubMed

Nexøe, J; Skifte, E; Niclasen, B; Munck, A

2012-01-01

Despite all efforts, recruitment of healthcare personnel has become increasingly difficult in Greenland as in other remote areas. The aim of this observational study was to describe the extent of health care delivered by nurses in Greenland's healthcare system. Reasons for encounter, diagnostic procedures, treatments and need for a physician's assistance, as well as the nurses' self-perceived competency, were also analysed. A total of 42 nurses registered all patient encounters for 10 days in late autumn 2006 in 14 out of 16 healthcare districts in Greenland. Nurses treated 1117 encounters (60%) singlehandedly. The nurses felt competent in what they were doing in 1415 encounters (76%). In 525 encounters (31%), a physician's advice was sought. Either the physician was asked to come or the physician's advice was obtained by telephone. In four cases the nurses did not feel completely competent, but did not seek advice from the physician on call. Feeling competent did not depend on length of experience in Greenland. In Greenland, nurses independently receive, diagnose and treat a substantial number of primary healthcare patients. The nurses take care of the patients and perform a number of clinical and laboratory procedures with great confidence. There has been speculation that part of the difficulty in recruiting doctors and healthcare personnel in remote areas may be due to uneasiness about professional responsibilities and, to some extent, lack of confidence. At least among the registering nurses in this study, this did not seem to be a problem.

Abdominal Wall Defects in Greenland 1989-2015.

PubMed

Bugge, Merete; Drachmann, Gitte; Kern, Peder; Budtz-Jørgensen, Esben; Eiberg, Hans; Olsen, Britta; Tommerup, Niels; Nielsen, Inge-Merete

2017-07-03

In the last decades, an increasing rate of gastroschisis but not of omphalocele has been reported worldwide. Greenland is the world's largest island, but 80% is covered by an ice cap, it has a small population of around 56,000 peoples (as of 2016). The occurrence of abdominal wall defects has never been investigated in Greenland. The present study is based on data retrieved from three nationwide and two local registries in the Greenlandic health care system over 27 years (1989-2015). We identified 33 infants with abdominal wall defects born in the study time period. All cases were reclassified to 28 cases of gastroschisis, four cases of omphalocele, and there was 1 infant in the indeterminate group. The point prevalence at birth for gastroschisis increased significantly from 8 to 35 (average 10.7) per 10,000 liveborn and -stillborn infants. Mothers below 20 years of age represented 23% of all cases and the prevalence for this group was 17 per 10,000 liveborn and stillborn. Perinatal mortality for infants with gastroschisis was high (18%), and 1 year survival was 71%. For omphalocele, the prevalence varied from 8 to 11 per 10,000 liveborn and stillborn infants. There was no increasing rate in the period, further highlighting an etiological difference between gastroschisis and omphalocele. This study confirms the increasing prevalence of gastroschisis in Greenland in the period from 1989 to 2015. The average was 10.7 per 10,000 liveborn and -stillborn infants and, to the best of our knowledge, this is the highest prevalence ever reported. Birth Defects Research 109:836-842, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Alaska Natives & the Land.

ERIC Educational Resources Information Center

Arnold, Robert D.; And Others

Pursuant to the Native land claims within Alaska, this compilation of background data and interpretive materials relevant to a fair resolution of the Alaska Native problem seeks to record data and information on the Native peoples; the land and resources of Alaska and their uses by the people in the past and present; land ownership; and future…

Alaska Women: A Databook.

ERIC Educational Resources Information Center

White, Karen; Baker, Barbara

This data book uses survey and census information to record social and economic changes of the past three decades and their effects upon the role of Alaska women in society. Results show Alaska women comprise 47% of the state population, an increase of 9% since 1950. Marriage continues as the predominant living arrangement for Alaska women,…

Alaska Board of Forestry

Science.gov Websites

Natural Resources / Division of Forestry Alaska Board of Forestry The nine-member Alaska Board of Forestry advises the state on forest practices issues and provides a forum for discussion and resolution of forest management issues on state land. The board also reviews all proposed changes to the Alaska Forest Resources

On the origin of multidecadal to centennial Greenland temperature anomalies over the past 800 yr

NASA Astrophysics Data System (ADS)

Kobashi, T.; Shindell, D. T.; Kodera, K.; Box, J. E.; Nakaegawa, T.; Kawamura, K.

2013-03-01

The surface temperature of the Greenland ice sheet is among the most important climate variables for assessing how climate change may impact human societies due to its association with sea level rise. However, the causes of multidecadal-to-centennial temperature changes in Greenland temperatures are not well understood, largely owing to short observational records. To examine these, we calculated the Greenland temperature anomalies (GTA[G-NH]) over the past 800 yr by subtracting the standardized northern hemispheric (NH) temperature from the standardized Greenland temperature. This decomposes the Greenland temperature variation into background climate (NH); polar amplification; and regional variability (GTA[G-NH]). The central Greenland polar amplification factor as expressed by the variance ratio Greenland/NH is 2.6 over the past 161 yr, and 3.3-4.2 over the past 800 yr. The GTA[G-NH] explains 31-35% of the variation of Greenland temperature in the multidecadal-to-centennial time scale over the past 800 yr. We found that the GTA[G-NH] has been influenced by solar-induced changes in atmospheric circulation patterns such as those produced by the North Atlantic Oscillation/Arctic Oscillation (NAO/AO). Climate modeling and proxy temperature records indicate that the anomaly is also likely linked to solar-paced changes in the Atlantic meridional overturning circulation (AMOC) and associated changes in northward oceanic heat transport.

On the Origin of Multidecadal to Centennial Greenland Temperature Anomalies Over the Past 800 yr

NASA Technical Reports Server (NTRS)

Kobashi, T.; Shindell, D. T.; Kodera, K.; Box, J. E.; Nakaegawa, T.; Kawamura, K.

2013-01-01

The surface temperature of the Greenland ice sheet is among the most important climate variables for assessing how climate change may impact human societies due to its association with sea level rise. However, the causes of multidecadal-to-centennial temperature changes in Greenland temperatures are not well understood, largely owing to short observational records. To examine these, we calculated the Greenland temperature anomalies (GTA[G-NH]) over the past 800 yr by subtracting the standardized northern hemispheric (NH) temperature from the standardized Greenland temperature. This decomposes the Greenland temperature variation into background climate (NH); polar amplification; and regional variability (GTA[G-NH]). The central Greenland polar amplification factor as expressed by the variance ratio Greenland/NH is 2.6 over the past 161 yr, and 3.3-4.2 over the past 800 yr. The GTA[G-NH] explains 31-35%of the variation of Greenland temperature in the multidecadal-to-centennial time scale over the past 800 yr. We found that the GTA[G-NH] has been influenced by solar-induced changes in atmospheric circulation patterns such as those produced by the North Atlantic Oscillation/Arctic Oscillation (NAO/AO). Climate modeling and proxy temperature records indicate that the anomaly is also likely linked to solar-paced changes in the Atlantic meridional overturning circulation (AMOC) and associated changes in northward oceanic heat transport.

Unnamed Glacial Canyon, Northern Greenland

NASA Image and Video Library

2017-12-08

A glacial canyon in northern Greenland as seen by NASA's P-3B aircraft on May 3, 2012. Credit: Michael Studinger/NASA =========== IceBridge, a six-year NASA mission, is the largest airborne survey of Earth's polar ice ever flown. It will yield an unprecedented three-dimensional view of Arctic and Antarctic ice sheets, ice shelves and sea ice. These flights will provide a yearly, multi-instrument look at the behavior of the rapidly changing features of the Greenland and Antarctic ice. Data collected during IceBridge will help scientists bridge the gap in polar observations between NASA's Ice, Cloud and Land Elevation Satellite (ICESat) -- in orbit since 2003 -- and ICESat-2, planned for early 2016. ICESat stopped collecting science data in 2009, making IceBridge critical for ensuring a continuous series of observations. IceBridge will use airborne instruments to map Arctic and Antarctic areas once a year. IceBridge flights are conducted in March-May over Greenland and in October-November over Antarctica. Other smaller airborne surveys around the world are also part of the IceBridge campaign. To read more about IceBridge - Arctic 2012 go to: www.nasa.gov/mission_pages/icebridge/index.html NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Unnamed Glacial Canyon, Northern Greenland

NASA Image and Video Library

2017-12-08

A northern Greenland glacier as seen by NASA's P-3B aircraft on May 3, 2012. Credit: Michael Studinger/NASA =========== IceBridge, a six-year NASA mission, is the largest airborne survey of Earth's polar ice ever flown. It will yield an unprecedented three-dimensional view of Arctic and Antarctic ice sheets, ice shelves and sea ice. These flights will provide a yearly, multi-instrument look at the behavior of the rapidly changing features of the Greenland and Antarctic ice. Data collected during IceBridge will help scientists bridge the gap in polar observations between NASA's Ice, Cloud and Land Elevation Satellite (ICESat) -- in orbit since 2003 -- and ICESat-2, planned for early 2016. ICESat stopped collecting science data in 2009, making IceBridge critical for ensuring a continuous series of observations. IceBridge will use airborne instruments to map Arctic and Antarctic areas once a year. IceBridge flights are conducted in March-May over Greenland and in October-November over Antarctica. Other smaller airborne surveys around the world are also part of the IceBridge campaign. To read more about IceBridge - Arctic 2012 go to: www.nasa.gov/mission_pages/icebridge/index.html NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Alaska Interagency Ecosystem Health Work Group

USGS Publications Warehouse

Shasby, Mark

2009-01-01

The Alaska Interagency Ecosystem Health Work Group is a community of practice that recognizes the interconnections between the health of ecosystems, wildlife, and humans and meets to facilitate the exchange of ideas, data, and research opportunities. Membership includes the Alaska Native Tribal Health Consortium, U.S. Geological Survey, Alaska Department of Environmental Conservation, Alaska Department of Health and Social Services, Centers for Disease Control and Prevention, U.S. Fish and Wildlife Service, Alaska Sea Life Center, U.S. Environmental Protection Agency, and Alaska Department of Fish and Game.

UNIT, ALASKA.

ERIC Educational Resources Information Center

Louisiana Arts and Science Center, Baton Rouge.

THE UNIT DESCRIBED IN THIS BOOKLET DEALS WITH THE GEOGRAPHY OF ALASKA. THE UNIT IS PRESENTED IN OUTLINE FORM. THE FIRST SECTION DEALS PRINCIPALLY WITH THE PHYSICAL GEOGRAPHY OF ALASKA. DISCUSSED ARE (1) THE SIZE, (2) THE MAJOR LAND REGIONS, (3) THE MOUNTAINS, VOLCANOES, GLACIERS, AND RIVERS, (4) THE NATURAL RESOURCES, AND (5) THE CLIMATE. THE…

Alaska's renewable energy potential.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

2009-02-01

This paper delivers a brief survey of renewable energy technologies applicable to Alaska's climate, latitude, geography, and geology. We first identify Alaska's natural renewable energy resources and which renewable energy technologies would be most productive. e survey the current state of renewable energy technologies and research efforts within the U.S. and, where appropriate, internationally. We also present information on the current state of Alaska's renewable energy assets, incentives, and commercial enterprises. Finally, we escribe places where research efforts at Sandia National Laboratories could assist the state of Alaska with its renewable energy technology investment efforts.

Oceans Melting Greenland (OMG): 2017 Observations and the First Look at Yearly Ocean/Ice Changes

NASA Astrophysics Data System (ADS)

Willis, J. K.; Rignot, E. J.; Fenty, I. G.; Khazendar, A.; Moller, D.; Tinto, K. J.; Morison, J.; Schodlok, M.; Thompson, A. F.; Fukumori, I.; Holland, D.; Forsberg, R.; Jakobsson, M.; Dinardo, S. J.

2017-12-01

Oceans Melting Greenland (OMG) is an airborne NASA Mission to investigate the role of the oceans in ice loss around the margins of the Greenland Ice Sheet. A five-year campaign, OMG will directly measure ocean warming and glacier retreat around all of Greenland. By relating these two, we will explore one of the most pressing open questions about how climate change drives sea level rise: How quickly are the warming oceans melting the Greenland Ice Sheet from the edges? This year, OMG collected its second set of both elevation maps of marine terminating glaciers and ocean temperature and salinity profiles around all of Greenland. This give us our first look at year-to-year changes in both ice volume at the margins, as well as the volume and extent of warm, salty Atlantic water present on the continental shelf. In addition, we will compare recent data in east Greenland waters with historical ocean observations that suggest a long-term warming trend there. Finally, we will briefly review the multi-beam sonar and airborne gravity campaigns—both of which were completed last year—and the dramatic improvement they had on bathymetry maps over the continental shelf around Greenland.

Pathways of Petermann Glacier's Meltwaters, Greenland

NASA Astrophysics Data System (ADS)

Heuzé, C.; Wahlin, A.; Johnson, H. L.; Muenchow, A.

2016-02-01

Radar and satellite observations suggest that the floating ice shelf of Petermann glacier, north Greenland, loses up to 80% of its mass through basal melting, caused by the intrusion of warm Atlantic water into the fjord and under the ice shelf. Although Greenland meltwaters are key to sea level rise projections and can potentially disrupt the whole ocean circulation, the fate of Petermann's glacial meltwater is still largely unknown. It is investigated here, using hydrographic observations collected during a research cruise onboard I/B Oden in August 2015. Two layers are found: one at 200 m (i.e. terminus depth) mostly on the eastern side of the fjord where a calving event occurred this summer, and one around 500 m depth (i.e. the grounding line) on the western side. At the sill, approximately 3 mSv of freshwater leave the fjord around 150 m on the eastern side. On the western side, a more complex circulation occurs as waters intrude in. Outside of the fjord in Hall Basin, only one layer is found, around 300 m, but its oxygen content and T-S properties suggests it is a mixture between Petermann's meltwater, meltwater from the neighbouring glaciers, surface run-off and sea ice. As Atlantic water warms up, it is key to monitor Greenland melting glaciers to properly assess sea level rise.

Perfluorinated alkyl substances (PFAS) in terrestrial environments in Greenland and Faroe Islands.

PubMed

Bossi, Rossana; Dam, Maria; Rigét, Frank F

2015-06-01

Perfluorinated alkylated substances (PFASs) have been measured in liver samples from terrestrial organisms from Greenland and the Faeroe Islands. Samples from ptarmigan (West Greenland), reindeer (southwest-Greenland), muskox (East Greenland), and land-locked Arctic char from southwest Greenland and the Faroe Islands were analyzed. In addition, PFASs levels in land-locked brown trout from Faroese lakes are reported. Of the 17 PFASs analyzed in the samples the following compounds were detected: PFOS, PFNA, PFDA, PFUnA, PFDoA, PFTrA, and PFTeA. PFNA was the compound detected in most samples and in all species. However, the compound detected at highest concentration was dependent on species, with overall highest concentrations of PFTrA and PFUnA being detected in trout liver from Lake á Mýranar (Faroe Islands). In muskox, the PFAS occurring at highest concentrations was PFDA, which was among the PFAS detected at lowest concentrations in freshwater fish, and was only detected in one individual ptarmigan. The concentration of PFOS, PFDoA and PFTrA in Arctic char from Greenland and Faroe Islands were similar, whereas the concentration of PFNA, PFDA and PFUnA were higher in Arctic char than those from Greenland. The opposite was observed for PFTeA. The PFASs occurring at highest concentrations in trout were PFTrA and PFUnA. Arctic char from Lake á Mýranar had much lower concentrations of PFTrA and PFUnA than in trout from the lakes analyzed, but a higher concentration of PFTeA than trout from the same lake. A clear pattern with odd-carbon number homologues concentrations higher than the next lower even homologue was observed in fish samples, which is consistent with the hypothesis of transport of volatile precursors to remote regions. Copyright © 2014 Elsevier Ltd. All rights reserved.

College Persistence of Alaska Native Students: An Assessment of the Rural Alaska Honors Institute, 1983-88.

ERIC Educational Resources Information Center

Gaylord, Thomas A.; Kaul, Gitanjali

Despite efforts by educators, full participation by Alaska native students in the state's colleges and universities has not yet been achieved. Alaska Natives are the state's only racial group that is underrepresented in enrollments at the University of Alaska (UA). This report examines the contribution of the Rural Alaska Honors Institute (RAHI)…

A Synthesis of the Basal Thermal State of the Greenland Ice Sheet

NASA Technical Reports Server (NTRS)

Macgregor, J. A.; Fahnestock, M. A.; Catania, G. A.; Aschwanden, A.; Clow, G. D.; Colgan, W. T.; Gogineni, S. P.; Morlighem, M.; Nowicki, S. M. J.; Paden, J. D.;

Trophic ecology of introduced populations of Alaska blackfish (Dallia pectoralis) in the Cook Inlet Basin, Alaska.

PubMed

Eidam, Dona M; von Hippel, Frank A; Carlson, Matthew L; Lassuy, Dennis R; López, J Andrés

2016-07-01

Introduced non-native fishes have the potential to substantially alter aquatic ecology in the introduced range through competition and predation. The Alaska blackfish ( Dallia pectoralis ) is a freshwater fish endemic to Chukotka and Alaska north of the Alaska Range (Beringia); the species was introduced outside of its native range to the Cook Inlet Basin of Alaska in the 1950s, where it has since become widespread. Here we characterize the diet of Alaska blackfish at three Cook Inlet Basin sites, including a lake, a stream, and a wetland. We analyze stomach plus esophageal contents to assess potential impacts on native species via competition or predation. Alaska blackfish in the Cook Inlet Basin consume a wide range of prey, with major prey consisting of epiphytic/benthic dipteran larvae, gastropods, and ostracods. Diets of the introduced populations of Alaska blackfish are similar in composition to those of native juvenile salmonids and stickleback. Thus, Alaska blackfish may affect native fish populations via competition. Fish ranked third in prey importance for both lake and stream blackfish diets but were of minor importance for wetland blackfish.

Trophic ecology of introduced populations of Alaska blackfish (Dallia pectoralis) in the Cook Inlet Basin, Alaska

PubMed Central

Eidam, Dona M.; Carlson, Matthew L.; Lassuy, Dennis R.; López, J. Andrés

2016-01-01

Introduced non-native fishes have the potential to substantially alter aquatic ecology in the introduced range through competition and predation. The Alaska blackfish (Dallia pectoralis) is a freshwater fish endemic to Chukotka and Alaska north of the Alaska Range (Beringia); the species was introduced outside of its native range to the Cook Inlet Basin of Alaska in the 1950s, where it has since become widespread. Here we characterize the diet of Alaska blackfish at three Cook Inlet Basin sites, including a lake, a stream, and a wetland. We analyze stomach plus esophageal contents to assess potential impacts on native species via competition or predation. Alaska blackfish in the Cook Inlet Basin consume a wide range of prey, with major prey consisting of epiphytic/benthic dipteran larvae, gastropods, and ostracods. Diets of the introduced populations of Alaska blackfish are similar in composition to those of native juvenile salmonids and stickleback. Thus, Alaska blackfish may affect native fish populations via competition. Fish ranked third in prey importance for both lake and stream blackfish diets but were of minor importance for wetland blackfish. PMID:28082763

Electrifying Alaska

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reinemer, V.

Alaska's diverse systems for electric power include only 4% by private utilities. Large distances and small markets make transmission impractical for the most part. Rates are variable, although the state average is low. Energy sources, except nuclear, are abundant: half the US coal reserves are in Alaska. In addition, it has geothermal, tidal, biomass, solar, wind, and hydroelectric power. Energy construction and study programs are centered in the Alaska Power Authority and include using waste heat from village diesel generators. Hydro potential is good, but access, distances, and environmental effects must be considered. The Terror Lake, Tyee Lake, Swan Lake,more » and Susitna projects are described and transmission construction, including the 345-kW Railbelt intertie, is discussed. 1 figure.« less

The extreme melt across the Greenland ice sheet in 2012

NASA Astrophysics Data System (ADS)

Nghiem, S. V.; Hall, D. K.; Mote, T. L.; Tedesco, M.; Albert, M. R.; Keegan, K.; Shuman, C. A.; DiGirolamo, N. E.; Neumann, G.

2012-10-01

The discovery of the 2012 extreme melt event across almost the entire surface of the Greenland ice sheet is presented. Data from three different satellite sensors - including the Oceansat-2 scatterometer, the Moderate-resolution Imaging Spectroradiometer, and the Special Sensor Microwave Imager/Sounder - are combined to obtain composite melt maps, representing the most complete melt conditions detectable across the ice sheet. Satellite observations reveal that melt occurred at or near the surface of the Greenland ice sheet across 98.6% of its entire extent on 12 July 2012, including the usually cold polar areas at high altitudes like Summit in the dry snow facies of the ice sheet. This melt event coincided with an anomalous ridge of warm air that became stagnant over Greenland. As seen in melt occurrences from multiple ice core records at Summit reported in the published literature, such a melt event is rare with the last significant one occurring in 1889 and the next previous one around seven centuries earlier in the Medieval Warm Period. Given its rarity, the 2012 extreme melt across Greenland provides an exceptional opportunity for new studies in broad interdisciplinary geophysical research.

Greenland as seen by the STS-66 shuttle Atlantis

NASA Technical Reports Server (NTRS)

1994-01-01

This north-looking view of southwestern Greenland was taken in November, 1994, and shows numerous indentations, many of which contain small settlements. These fjords were carved by the glaciers of the last ice age 10,000 years ago. Even today, the ice in the center of Greenland is nearly 3,500 meters (11,000 feet) thick and great rivers of ice continuously flow down toward the sea, where they melt or break off as icebergs. Some Icebergs exceed the size of small islands, weigh several million tons, and rise several hundred feet above the sea surface. Cape Farewell is visible toward the bottom right of the view. Julianehab Bay and the Bredev fjord can be seen toward the center of the photograph. Godthab, the main settlement on Greenland, is barely visible to the north of the Frederikeshabs Icefield near the left center of the view.

Greenland as seen by the STS-66 shuttle Atlantis

NASA Image and Video Library

1994-11-14

This north-looking view of southwestern Greenland was taken in November, 1994, and shows numerous indentations, many of which contain small settlements. These fjords were carved by the glaciers of the last ice age 10,000 years ago. Even today, the ice in the center of Greenland is nearly 3,500 meters (11,000 feet) thick and great rivers of ice continuously flow down toward the sea, where they melt or break off as icebergs. Some Icebergs exceed the size of small islands, weigh several million tons, and rise several hundred feet above the sea surface. Cape Farewell is visible toward the bottom right of the view. Julianehab Bay and the Bredev fjord can be seen toward the center of the photograph. Godthab, the main settlement on Greenland, is barely visible to the north of the Frederikeshabs Icefield near the left center of the view.

IGLOO: an Intermediate Complexity Framework to Simulate Greenland Ice-Ocean Interactions

NASA Astrophysics Data System (ADS)

Perrette, M.; Calov, R.; Beckmann, J.; Alexander, D.; Beyer, S.; Ganopolski, A.

2017-12-01

The Greenland ice-sheet is a major contributor to current and future sea level rise associated to climate warming. It is widely believed that over a century time scale, surface melting is the main driver of Greenland ice volume change, in contrast to melting by the ocean. It is due to relatively warmer air and less ice area exposed to melting by ocean water compared to Antarctica, its southern, larger twin. Yet most modeling studies do not have adequate grid resolution to represent fine-scale outlet glaciers and fjords at the margin of the ice sheet, where ice-ocean interaction occurs, and must use rather crude parameterizations to represent this process. Additionally, the ice-sheet area grounded below sea level has been reassessed upwards in the most recent estimates of bedrock elevation under the Greenland ice sheet, revealing a larger potential for marine-mediated melting than previously thought. In this work, we develop an original approach to estimate potential Greenland ice sheet contribution to sea level rise from ocean melting, in an intermediate complexity framework, IGLOO. We use a medium-resolution (5km) ice-sheet model coupled interactively to a number of 1-D flowline models for the individual outlet glaciers. We propose a semi-objective methodology to derive 1-D glacier geometries from 2-D Greenland datasets, as well as preliminary results of coupled ice-sheet-glaciers simulations with IGLOO.

Linking petrology and seismology of the southwest Greenland lithosphere

NASA Astrophysics Data System (ADS)

Lesher, C. E.; Vestergaard, C.; Brown, E.; Schutt, D.

2015-12-01

Mantle xenoliths from late-Proterozoic diamond-bearing kimberlitic dikes in the Kangerlussuaq, Sarfartoq and Maniitsoq areas of southwestern Greenland provide constraints on the composition and thermal state of lithospheric mantle beneath Greenland to depths of ~200 km [1]. Similarly, surface wave tomography studies carried out as part of the GLATIS project use a range of Rayleigh wave periods sensitive to structures at a similar depth interval within southwestern Greenland lithospheric mantle [2]. Here we link petrologic and seismologic constraints on the mantle lithosphere beneath Greenland utilizing methods of [3] that show that inferred chemical and mineralogical stratification inferred from petrology, showing mantle peridotite transitioning from garnet-free harzburgite to garnet lherzolite between ~70 and 180 km, cannot readily be resolved with fundamental mode Rayleigh waves. On the other hand, comparing phase velocities predicted from xenolith compositions, mineralogy and last equilibration temperatures and pressures, defining the continental geotherm during late-Proterozoic time, with those for the present-day mantle lithosphere suggest significant cooling of the cratonic mantle to a modern geotherm characterized by a heat flux of 30 mW/m2 and average crustal heat production of 0.3 mW/m3 [4]. These preliminary findings point to the weak dependence of shear wave velocities on mantle peridotite composition and mineralogy, and further illustrate its strong temperature dependence. Comparison of ancient and modern continental geotherms made possible by combining petrologic and seismological data, as shown here for southwest Greenland, provide additional constraints on secular cooling of cratonic regions linked to large-scale tectonic processes. [1] Bizzarro et al., 2003, CMP, 146; Sand et al., Lithos, 112. [2] Darbyshire et al., 2004, GJI, 158. [3] Schutt and Lesher, 2006, JGR, 111. [4] Meirerbachtol et al., 2015, JGR/ES, 120.

Radiostratigraphy and age structure of the Greenland Ice Sheet

PubMed Central

MacGregor, Joseph A; Fahnestock, Mark A; Catania, Ginny A; Paden, John D; Prasad Gogineni, S; Young, S Keith; Rybarski, Susan C; Mabrey, Alexandria N; Wagman, Benjamin M; Morlighem, Mathieu

2015-01-01

Several decades of ice-penetrating radar surveys of the Greenland and Antarctic ice sheets have observed numerous widespread internal reflections. Analysis of this radiostratigraphy has produced valuable insights into ice sheet dynamics and motivates additional mapping of these reflections. Here we present a comprehensive deep radiostratigraphy of the Greenland Ice Sheet from airborne deep ice-penetrating radar data collected over Greenland by The University of Kansas between 1993 and 2013. To map this radiostratigraphy efficiently, we developed new techniques for predicting reflection slope from the phase recorded by coherent radars. When integrated along track, these slope fields predict the radiostratigraphy and simplify semiautomatic reflection tracing. Core-intersecting reflections were dated using synchronized depth-age relationships for six deep ice cores. Additional reflections were dated by matching reflections between transects and by extending reflection-inferred depth-age relationships using the local effective vertical strain rate. The oldest reflections, dating to the Eemian period, are found mostly in the northern part of the ice sheet. Within the onset regions of several fast-flowing outlet glaciers and ice streams, reflections typically do not conform to the bed topography. Disrupted radiostratigraphy is also observed in a region north of the Northeast Greenland Ice Stream that is not presently flowing rapidly. Dated reflections are used to generate a gridded age volume for most of the ice sheet and also to determine the depths of key climate transitions that were not observed directly. This radiostratigraphy provides a new constraint on the dynamics and history of the Greenland Ice Sheet. Key Points Phase information predicts reflection slope and simplifies reflection tracing Reflections can be dated away from ice cores using a simple ice flow model Radiostratigraphy is often disrupted near the onset of fast ice flow PMID:26213664

Measured and modelled absolute gravity in Greenland

NASA Astrophysics Data System (ADS)

Nielsen, E.; Forsberg, R.; Strykowski, G.

2012-12-01

Present day changes in the ice volume in glaciated areas like Greenland will change the load on the Earth and to this change the lithosphere will respond elastically. The Earth also responds to changes in the ice volume over a millennial time scale. This response is due to the viscous properties of the mantle and is known as Glaical Isostatic Adjustment (GIA). Both signals are present in GPS and absolute gravity (AG) measurements and they will give an uncertainty in mass balance estimates calculated from these data types. It is possible to separate the two signals if both gravity and Global Positioning System (GPS) time series are available. DTU Space acquired an A10 absolute gravimeter in 2008. One purpose of this instrument is to establish AG time series in Greenland and the first measurements were conducted in 2009. Since then are 18 different Greenland GPS Network (GNET) stations visited and six of these are visited more then once. The gravity signal consists of three signals; the elastic signal, the viscous signal and the direct attraction from the ice masses. All of these signals can be modelled using various techniques. The viscous signal is modelled by solving the Sea Level Equation with an appropriate ice history and Earth model. The free code SELEN is used for this. The elastic signal is modelled as a convolution of the elastic Greens function for gravity and a model of present day ice mass changes. The direct attraction is the same as the Newtonian attraction and is calculated as this. Here we will present the preliminary results of the AG measurements in Greenland. We will also present modelled estimates of the direct attraction, the elastic and the viscous signals.

Leakage of the Greenland Ice Sheet through accelerated ice flow

NASA Astrophysics Data System (ADS)

Rignot, E.

2005-12-01

A map of coastal velocities of the Greenland ice sheet was produced from Radarsat-1 acquired during the background mission of 2000 and combined with radio echo sounding data to estimate the ice discharge from the ice sheet. On individual glaciers, ice discharge was compared with snow input from the interior and melt above the flux gate to determine the glacier mass balance. Time series of velocities on several glaciers at different latitudes reveal seasonal fluctuations of only 7-8 percent so that winter velocities are only 2 percent less than the yearly mean. The results show the northern Greenland glaciers to be close to balance yet losing mass. No change in ice flow is detected on Petermann, 79north and Zachariae Isstrom in 2000-2004. East Greenland glaciers are in balance and flowing steadily north of Kangerdlussuaq, but Kangerdlussuaq, Helheim and all the southeastern glaciers are thinning dramatically. All these glaciers accelerated, Kangerdlussuaq in 2000, Helheim prior to 2004, and southeast Greenland glaciers accelerated 10 to 50 percent in 2000-2004. Glacier acceleration is generally brutal, probably once the glacier reached a threshold, and sustained. In the northwest, most glaciers are largely out of balance. Jakobshavn accelerated significantly in 2002, and glaciers in its immediate vicinity accelerated more than 50 percent in 2000-2004. Less is known about southwest Greenland glaciers due to a lack of ice thickness data but the glaciers have accelerated there as well and are likely to be strongly out of balance despite thickening of the interior. Overall, I estimate the mass balance of the Greenland ice sheet to be about -80 +/-10 cubic km of ice per year in 2000 and -110 +/-15 cubic km of ice per year in 2004, i.e. more negative than based on partial altimetry surveys of the outlet glaciers. As climate continues to warm, more glaciers will accelerate, and the mass balance will become increasingly negative, regardless of the evolution of the ice sheet

Lithospheric Structure of Greenland from Ambient Noise and Earthquake Surface Wave Tomography

NASA Astrophysics Data System (ADS)

Pourpoint, M.; Anandakrishnan, S.; Ammon, C. J.

2017-12-01

We present a high resolution seismic tomography model of Greenland's lithosphere from surface wave analysis. Regional and teleseismic events recorded by GLISN over the last 20 years were used. We developed a new group velocity correction method to alleviate the limitations of the sparse network and the relatively few local events. The global dispersion model GDM52 was used to calculate group delays from the earthquake to the boundaries of our study area. To better constrain the crustal structure of Greenland and cross-validate our group velocity correction approach, we also collected and processed several years of ambient noise data. An iterative reweighted generalized least-square scheme was used to invert for the group velocity maps and a Markov chain Monte Carlo technique was applied to invert for a 3-D shear wave velocity model of Greenland up to a depth of 200 km. Our shear wave velocity model is consistent with previous studies but of higher resolution and we show that in regions with limited station coverage and local seismicity, we can rely on global models to construct relatively large local data sets that can provide some important constraints on regional structures. Our model contains the signature of known geological features and reveals three prominent anomalies: a shallow low-velocity anomaly between central-eastern and northeastern Greenland that correlates well with a previously measured high geothermal heat flux; a deep high-velocity anomaly extending from southwestern to northwestern Greenland that could be interpreted as the signature of a thick Archean keel; and a deep low-velocity anomaly in central-eastern Greenland that could be associated with lithospheric thinning and upwelling of hot asthenosphere material from the rifting of the Atlantic Ocean around 60 Ma and the passage of the Icelandic mantle plume beneath Greenland between 70 and 30 Ma. Upper mantle temperature and heat flux distribution beneath Greenland are further derived from our

Publications - GMC 193 | Alaska Division of Geological & Geophysical

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Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical materials: Alaska State F #1, washed cuttings (13,980' - 13,990'); West Mikkelsen State #1, Canning River

Ice Core Records of Recent Northwest Greenland Climate

NASA Astrophysics Data System (ADS)

Osterberg, E. C.; Wong, G. J.; Ferris, D.; Lutz, E.; Howley, J. A.; Kelly, M. A.; Axford, Y.; Hawley, R. L.

2014-12-01

Meteorological station data from NW Greenland indicate a 3oC temperature rise since 1990, with most of the warming occurring in fall and winter. According to remote sensing data, the NW Greenland ice sheet (GIS) and coastal ice caps are responding with ice mass loss and margin retreat, but the cryosphere's response to previous climate variability is poorly constrained in this region. We are developing multi-proxy records (lake sediment cores, ice cores, glacial geologic data, glaciological models) of Holocene climate change and cryospheric response in NW Greenland to improve projections of future ice loss and sea level rise in a warming climate. As part of our efforts to develop a millennial-length ice core paleoclimate record from the Thule region, we collected and analyzed snow pit samples and short firn cores (up to 21 m) from the coastal region of the GIS (2Barrel site; 76.9317o N, 63.1467o W, 1685 m el.) and the summit of North Ice Cap (76.938o N, 67.671o W, 1273 m el.) in 2011, 2012 and 2014. The 2Barrel ice core record has statistically significant relationships with regional spring and fall Baffin Bay sea ice extent, summertime temperature, and annual precipitation. Here we evaluate relationships between the 2014 North Ice Cap firn core glaciochemical record and climate variability from regional instrumental stations and reanalysis datasets. We compare the coastal North Ice Cap record to more inland records from 2Barrel, Camp Century and NEEM to evaluate spatial and elevational gradients in recent NW Greenland climate change.

Surface-atmosphere decoupling limits accumulation at Summit, Greenland

PubMed Central

Berkelhammer, Max; Noone, David C.; Steen-Larsen, Hans Christian; Bailey, Adriana; Cox, Christopher J.; O’Neill, Michael S.; Schneider, David; Steffen, Konrad; White, James W. C.

2016-01-01

Despite rapid melting in the coastal regions of the Greenland Ice Sheet, a significant area (~40%) of the ice sheet rarely experiences surface melting. In these regions, the controls on annual accumulation are poorly constrained owing to surface conditions (for example, surface clouds, blowing snow, and surface inversions), which render moisture flux estimates from myriad approaches (that is, eddy covariance, remote sensing, and direct observations) highly uncertain. Accumulation is partially determined by the temperature dependence of saturation vapor pressure, which influences the maximum humidity of air parcels reaching the ice sheet interior. However, independent proxies for surface temperature and accumulation from ice cores show that the response of accumulation to temperature is variable and not generally consistent with a purely thermodynamic control. Using three years of stable water vapor isotope profiles from a high altitude site on the Greenland Ice Sheet, we show that as the boundary layer becomes increasingly stable, a decoupling between the ice sheet and atmosphere occurs. The limited interaction between the ice sheet surface and free tropospheric air reduces the capacity for surface condensation to achieve the rate set by the humidity of the air parcels reaching interior Greenland. The isolation of the surface also acts to recycle sublimated moisture by recondensing it onto fog particles, which returns the moisture back to the surface through gravitational settling. The observations highlight a unique mechanism by which ice sheet mass is conserved, which has implications for understanding both past and future changes in accumulation rate and the isotopic signal in ice cores from Greenland. PMID:27386509

Surface-atmosphere decoupling limits accumulation at Summit, Greenland.

PubMed

Berkelhammer, Max; Noone, David C; Steen-Larsen, Hans Christian; Bailey, Adriana; Cox, Christopher J; O'Neill, Michael S; Schneider, David; Steffen, Konrad; White, James W C

2016-04-01

Despite rapid melting in the coastal regions of the Greenland Ice Sheet, a significant area (~40%) of the ice sheet rarely experiences surface melting. In these regions, the controls on annual accumulation are poorly constrained owing to surface conditions (for example, surface clouds, blowing snow, and surface inversions), which render moisture flux estimates from myriad approaches (that is, eddy covariance, remote sensing, and direct observations) highly uncertain. Accumulation is partially determined by the temperature dependence of saturation vapor pressure, which influences the maximum humidity of air parcels reaching the ice sheet interior. However, independent proxies for surface temperature and accumulation from ice cores show that the response of accumulation to temperature is variable and not generally consistent with a purely thermodynamic control. Using three years of stable water vapor isotope profiles from a high altitude site on the Greenland Ice Sheet, we show that as the boundary layer becomes increasingly stable, a decoupling between the ice sheet and atmosphere occurs. The limited interaction between the ice sheet surface and free tropospheric air reduces the capacity for surface condensation to achieve the rate set by the humidity of the air parcels reaching interior Greenland. The isolation of the surface also acts to recycle sublimated moisture by recondensing it onto fog particles, which returns the moisture back to the surface through gravitational settling. The observations highlight a unique mechanism by which ice sheet mass is conserved, which has implications for understanding both past and future changes in accumulation rate and the isotopic signal in ice cores from Greenland.

Abrupt shift in the observed runoff from the southwestern Greenland ice sheet

PubMed Central

Ahlstrøm, Andreas P.; Petersen, Dorthe; Langen, Peter L.; Citterio, Michele; Box, Jason E.

2017-01-01

The recent decades of accelerating mass loss of the Greenland ice sheet have arisen from an increase in both surface meltwater runoff and ice flow discharge from tidewater glaciers. Despite the role of the Greenland ice sheet as the dominant individual cryospheric contributor to sea level rise in recent decades, no observational record of its mass loss spans the 30-year period needed to assess its climatological state. We present for the first time a 40-year (1975–2014) time series of observed meltwater discharge from a >6500-km2 catchment of the southwestern Greenland ice sheet. We find that an abrupt 80% increase in runoff occurring between the 1976–2002 and 2003–2014 periods is due to a shift in atmospheric circulation, with meridional exchange events occurring more frequently over Greenland, establishing the first observation-based connection between ice sheet runoff and climate change. PMID:29242827

Joint Science Education Project: Learning about polar science in Greenland

NASA Astrophysics Data System (ADS)

Foshee Reed, Lynn

2014-05-01

The Joint Science Education Project (JSEP) is a successful summer science and culture opportunity in which students and teachers from the United States, Denmark, and Greenland come together to learn about the research conducted in Greenland and the logistics involved in supporting the research. They conduct experiments first-hand and participate in inquiry-based educational activities alongside scientists and graduate students at a variety of locations in and around Kangerlussuaq, Greenland, and on the top of the ice sheet at Summit Station. The Joint Committee, a high-level forum involving the Greenlandic, Danish and U.S. governments, established the Joint Science Education Project in 2007, as a collaborative diplomatic effort during the International Polar Year to: • Educate and inspire the next generation of polar scientists; • Build strong networks of students and teachers among the three countries; and • Provide an opportunity to practice language and communication skills Since its inception, JSEP has had 82 student and 22 teacher participants and has involved numerous scientists and field researchers. The JSEP format has evolved over the years into its current state, which consists of two field-based subprograms on site in Greenland: the Greenland-led Kangerlussuaq Science Field School and the U.S.-led Arctic Science Education Week. All travel, transportation, accommodations, and meals are provided to the participants at no cost. During the 2013 Kangerlussuaq Science Field School, students and teachers gathered data in a biodiversity study, created and set geo- and EarthCaches, calculated glacial discharge at a melt-water stream and river, examined microbes and tested for chemical differences in a variety of lakes, measured ablation at the edge of the Greenland Ice Sheet, and learned about fossils, plants, animals, minerals and rocks of Greenland. In addition, the students planned and led cultural nights, sharing food, games, stories, and traditions of

Forty years of research concerning children and youth in Greenland: a mapping review

PubMed Central

Glendøs, Mia; Berliner, Peter

2017-01-01

ABSTRACT Objective: This study undertakes a mapping review of mainly concerning children and youth in Greenland in the period 1976–2016 and reflects on how the research has been conducted and knowledge thereby created about children and youth in Greenland, as well as how the research has been developed over time. Design: 16 online databases; five journals; publication lists originating from seven organisations and ten prominent researchers; and local network and references were used in the search and subsequently screened through the scoping criteria. 342 publications were included, encompassing knowledge based on empirical research on children and youth in Greenland within the broader field of psychology. Results: The majority of studies, 71%, were conducted through quantitative methods. The qualitative research is represented in 22% of the studies and participatory and action-orientated research is represented in 7% of the studies. The most prominent themes in research concerning children and youth in Greenland were physical problems, which were found in 38% of the studies. Conclusions: The result reflects a consistent objectivity and quantitative methodology in health research in Greenland since 1991.The health research thus represents a united research community with a shared methodological research approach, while the local participatory action research projects all appear differentiated. While health research covers a spectrum of psychology related objectives, the methodology traditions reveal a specific kind of knowledge, which has come to determine how the mental health of the Greenlandic children is perceived. We believe that more qualitative and locally grounded approaches need to be organised in order to produce a more nuanced knowledge of the Greenlandic children and youth. PMID:28661236

Hotspots and key periods of Greenland climate change during the past six decades

NASA Astrophysics Data System (ADS)

Abermann, J.; Hansen, B. U.; Lund, M.; Wacker, S.; Karami, M.; Cappelen, J.

2016-12-01

We investigate spatial gradients of air temperature and pressure and their trends in Greenland and compare these considering varying time window lengths since 1958. Both latitudinal temperature and pressure gradients are strongest during winter. An overall temperature increase of up to 0.15°C yr-1 has been observed for 1996-2014. The strongest warming happened during February at the West Coast (up to 0.6°C/yr), weaker but significant warming occurred during summer months (up to 0.3°C/yr) both in West and in East Greenland. Pressure trends are mainly negative if at all, but largely not significant. We discuss the relevance of these findings in an upscaling context of an extensive ecosystem monitoring program that was established in 1996 in Northeast Greenland (Zackenberg, www.g-e-m.dk). Improving the understanding of the interaction between the individual components of the ecosystem is its core idea, climate being the main driver. A series of studies highlights trends and variability for biotic and abiotic parameters for this period on a point scale. In order to expand trend assessments to a Greenland-wide scale, local climate trends in Zackenberg have to be put into a larger spatio-temporal context. We find that temperature trends in Northeast Greenland and the area around Zackenberg follow the general pattern but are smaller than the average in Greenland. Compared with other time windows in the past 6 decades, the study period 1996 - 2014 marks an above average warming trend; peak warming however occurred half a decade earlier. We therefore conclude that temperature-driven ecosystem changes observed in Zackenberg mark a lower boundary for environmental changes in Greenland.

MIS-11 duration key to disappearance of the Greenland ice sheet

PubMed Central

Robinson, Alexander; Alvarez-Solas, Jorge; Calov, Reinhard; Ganopolski, Andrey; Montoya, Marisa

2017-01-01

Palaeo data suggest that Greenland must have been largely ice free during Marine Isotope Stage 11 (MIS-11). However, regional summer insolation anomalies were modest during this time compared to MIS-5e, when the Greenland ice sheet likely lost less volume. Thus it remains unclear how such conditions led to an almost complete disappearance of the ice sheet. Here we use transient climate–ice sheet simulations to simultaneously constrain estimates of regional temperature anomalies and Greenland’s contribution to the MIS-11 sea-level highstand. We find that Greenland contributed 6.1 m (3.9–7.0 m, 95% credible interval) to sea level, ∼7 kyr after the peak in regional summer temperature anomalies of 2.8 °C (2.1–3.4 °C). The moderate warming produced a mean rate of mass loss in sea-level equivalent of only around 0.4 m per kyr, which means the long duration of MIS-11 interglacial conditions around Greenland was a necessary condition for the ice sheet to disappear almost completely. PMID:28681860

Alaska's State Forests

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Conservation Education Timber Management Wildland Fire & Aviation Burn Permits Firewise Alaska Brochure (PDF) Fire Management Plans Fire Assignments Annual Fire Statistics Fire Terms Glossary Incident Business Management Grants Become an Alaska Firewise Community Community Wildland Fire Protection Plans

How Will Sea Ice Loss Affect the Greenland Ice Sheet? On the Puzzling Features of Greenland Ice-Core Isotopic Composition

NASA Technical Reports Server (NTRS)

Pausata, Francesco S. R.; Legrande, Allegra N.; Roberts, William H. G.

2016-01-01

The modern cryosphere, Earth's frozen water regime, is in fast transition. Greenland ice cores show how fast theses changes can be, presenting evidence of up to 15 C warming events over timescales of less than a decade. These events, called Dansgaard/Oeschger (D/O) events, are believed to be associated with rapid changes in Arctic sea ice, although the underlying mechanisms are still unclear. The modern demise of Arctic sea ice may, in turn, instigate abrupt changes on the Greenland Ice Sheet. The Arctic Sea Ice and Greenland Ice Sheet Sensitivity (Ice2Ice Chttps://ice2ice.b.uib.noD) initiative, sponsored by the European Research Council, seeks to quantify these past rapid changes to improve our understanding of what the future may hold for the Arctic. Twenty scientists gathered in Copenhagen as part of this initiative to discuss the most recent observational, technological, and model developments toward quantifying the mechanisms behind past climate changes in Greenland. Much of the discussion focused on the causes behind the changes in stable water isotopes recorded in ice cores. The participants discussed sources of variability for stable water isotopes and framed ways that new studies could improve understanding of modern climate. The participants also discussed how climate models could provide insights into the relative roles of local and nonlocal processes in affecting stable water isotopes within the Greenland Ice Sheet. Presentations of modeling results showed how a change in the source or seasonality of precipitation could occur not only between glacial and modern climates but also between abrupt events. Recent fieldwork campaigns illustrate an important role of stable isotopes in atmospheric vapor and diffusion in the final stable isotope signal in ice. Further, indications from recent fieldwork campaigns illustrate an important role of stable isotopes in atmospheric vapor and diffusion in the final stable isotope signal in ice. This feature complicates

49 CFR 71.11 - Alaska zone.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false Alaska zone. 71.11 Section 71.11 Transportation Office of the Secretary of Transportation STANDARD TIME ZONE BOUNDARIES § 71.11 Alaska zone. The sixth zone, the Alaska standard time zone, includes the entire State of Alaska, except as provided in § 71.12...

Greenland ice sheet albedo variability and feedback: 2000-2015

NASA Astrophysics Data System (ADS)

Box, J. E.; van As, D.; Fausto, R. S.; Mottram, R.; Langen, P. P.; Steffen, K.

2015-12-01

Absorbed solar irradiance represents the dominant source of surface melt energy for Greenland ice. Surface melting has increased as part of a positive feedback amplifier due to surface darkening. The 16 most recent summers of observations from the NASA MODIS sensor indicate a darkening exceeding 6% in July when most melting occurs. Without the darkening, the increase in surface melting would be roughly half as large. A minority of the albedo decline signal may be from sensor degradation. So, in this study, MOD10A1 and MCD43 albedo products from MODIS are evaluated for sensor degradation and anisotropic reflectance errors. Errors are minimized through calibration to GC-Net and PROMICE Greenland snow and ice ground control data. The seasonal and spatial variability in Greenland snow and ice albedo over a 16 year period is presented, including quantifying changing absorbed solar irradiance and melt enhancement due to albedo feedback using the DMI HIRHAM5 5 km model.

Towards Greenland Glaciation: Cumulative or Abrupt Transition?

NASA Astrophysics Data System (ADS)

Tan, N.; Ramstein, G.; Contoux, C.; Ladant, J. B.; Dumas, C.; Donnadieu, Y.

2014-12-01

The insolation evolution [Laskar 2004] from 4 to 2.5 Ma depicts a series of three summer solstice insolation minima between 2.7 and 2.6 Ma, but there are other more important summer solstice minima notably around 3.82 and 3.05 Ma. On such a time span of more than 1 Ma, data shows that there are variations in the evolution of atmospheric CO2 concentration with a local maximum around 3 Ma [Seki et al.2010; Bartoli et al. 2011], before a decrease between 3 and 2.6 Ma. The latter, suggesting an abrupt ice sheet inception around 2.7 Ma, has been shown to be a major culprit for the full Greenland Glaciation [Lunt et al. 2008]. However, a recent study [Contoux et al. 2014, in review] suggests that a lowering of CO2 is not sufficient to initiate a glaciation on Greenland and must be combined to low summer insolation, with surviving ice during insolation maximum, suggesting a cumulative process in the first place, which could further lead to full glaciation at 2.7 Ma. Through a new tri-dimensional interpolation method implemented within the asynchronous coupling between an atmosphere ocean general circulation model (IPSL-CM5A) and an ice sheet model (GRISLI), we investigate the transient evolution of Greenland ice sheet during the Pliocene to diagnose whether the ice sheet inception is an abrupt event or rather a cumulative process, involving waxing and waning of the ice sheet during several orbital cycles. ReferencesBartoli, G., Hönisch, B., & Zeebe, R. E. (2011). Atmospheric CO2 decline during the Pliocene intensification of Northern Hemisphere glaciations. Paleoceanography, 26(4). Contoux C, Dumas C, Ramstein G, Jost A, Dolan A. M. (2014) Modelling Greenland Ice sheet inception and sustainability during the late Pliocene. (in review for Earth and Planetary Science Letters.).Laskar, J., Robutel, P., Joutel, F., Gastineau, M., Correia, A. C. M., & Levrard, B. (2004). A long-term numerical solution for the insolation quantities of the Earth. Astronomy & Astrophysics, 428

Modelling Greenland Outlet Glaciers

NASA Technical Reports Server (NTRS)

vanderVeen, Cornelis; Abdalati, Waleed (Technical Monitor)

2001-01-01

The objective of this project was to develop simple yet realistic models of Greenland outlet glaciers to better understand ongoing changes and to identify possible causes for these changes. Several approaches can be taken to evaluate the interaction between climate forcing and ice dynamics, and the consequent ice-sheet response, which may involve changes in flow style. To evaluate the icesheet response to mass-balance forcing, Van der Veen (Journal of Geophysical Research, in press) makes the assumption that this response can be considered a perturbation on the reference state and may be evaluated separately from how this reference state evolves over time. Mass-balance forcing has an immediate effect on the ice sheet. Initially, the rate of thickness change as compared to the reference state equals the perturbation in snowfall or ablation. If the forcing persists, the ice sheet responds dynamically, adjusting the rate at which ice is evacuated from the interior to the margins, to achieve a new equilibrium. For large ice sheets, this dynamic adjustment may last for thousands of years, with the magnitude of change decreasing steadily over time as a new equilibrium is approached. This response can be described using kinematic wave theory. This theory, modified to pertain to Greenland drainage basins, was used to evaluate possible ice-sheet responses to perturbations in surface mass balance. The reference state is defined based on measurements along the central flowline of Petermann Glacier in north-west Greenland, and perturbations on this state considered. The advantage of this approach is that the particulars of the dynamical flow regime need not be explicitly known but are incorporated through the parameterization of the reference ice flux or longitudinal velocity profile. The results of the kinematic wave model indicate that significant rates of thickness change can occur immediately after the prescribed change in surface mass balance but adjustments in flow

Insect-Based Holocene (and Last Interglacial?) Paleothermometry from the E and NW Greenland Ice Sheet Margins: A Fly's-Eye View of Warmth on Greenland

NASA Astrophysics Data System (ADS)

Axford, Y.; Bigl, M.; Carrio, C.; Corbett, L. B.; Francis, D. R.; Hall, B. L.; Kelly, M. A.; Levy, L.; Lowell, T. V.; Osterberg, E. C.; Richter, N.; Roy, E.; Schellinger, G. C.

2013-12-01

Here we present new paleotemperature reconstructions based upon insect (Chironomidae) assemblages and other proxies from lake sediment cores recovered in east Greenland at ~71° N near Scoresby Sund and in northwest Greenland at ~77° N near Thule/Qaanaaq. In east Greenland, Last Chance Lake (informal name) is a small, non-glacial lake situated ~90 km east of the Greenland Ice Sheet margin. The lake preserves a sedimentary record of the entire Holocene (Levy et al. 2013). Chironomids from Last Chance Lake record cold summer temperatures (and establishment of a cold-climate fauna including abundant Oliveridia and Pseudodiamesa) during the late Holocene, preceded by summer temperatures estimated to have been 3 to 6°C warmer during the first half of the Holocene (when summer insolation forcing was greater than today). In northwest Greenland, Delta Sø and Wax Lips Lake (informal name) both preserve Holocene sediments. Here we discuss the late Holocene chironomid record from Delta Sø, whereas from Wax Lips Lake (a small, non-glacial lake situated ~2 km west of the ice sheet margin) we present a longer sedimentary and biostratigraphic record. The deeper portions of cores from Wax Lips Lake yield pre-Holocene and nonfinite radiocarbon ages, suggesting that this lake preserves sediments predating the Last Glacial Maximum. Abundant chironomids in the pre-glacial sediments appear to record interglacial conditions, and we infer that these sediments may date to the Last Interglacial (Eemian). The preservation of in situ Last Interglacial lacustrine sediments so close to the modern ice sheet margin suggests a minimally erosive glacierization style throughout the last glacial period, like that inferred for other Arctic locales such as on Baffin Island (Briner et al. 2007), ~750 km southwest of our study site. Our study sites are situated nearby key ice core sites (including NEEM, Camp Century, Agassiz and Renland) and very close to the ice sheet margin. These chironomid

Insect-Based Holocene (and Last Interglacial?) Paleothermometry from the E and NW Greenland Ice Sheet Margins: A Fly's-Eye View of Warmth on Greenland

NASA Astrophysics Data System (ADS)

Axford, Y.; Bigl, M.; Carrio, C.; Corbett, L. B.; Francis, D. R.; Hall, B. L.; Kelly, M. A.; Levy, L.; Lowell, T. V.; Osterberg, E. C.; Richter, N.; Roy, E.; Schellinger, G. C.

2011-12-01

Here we present new paleotemperature reconstructions based upon insect (Chironomidae) assemblages and other proxies from lake sediment cores recovered in east Greenland at ~71° N near Scoresby Sund and in northwest Greenland at ~77° N near Thule/Qaanaaq. In east Greenland, Last Chance Lake (informal name) is a small, non-glacial lake situated ~90 km east of the Greenland Ice Sheet margin. The lake preserves a sedimentary record of the entire Holocene (Levy et al. 2013). Chironomids from Last Chance Lake record cold summer temperatures (and establishment of a cold-climate fauna including abundant Oliveridia and Pseudodiamesa) during the late Holocene, preceded by summer temperatures estimated to have been 3 to 6°C warmer during the first half of the Holocene (when summer insolation forcing was greater than today). In northwest Greenland, Delta Sø and Wax Lips Lake (informal name) both preserve Holocene sediments. Here we discuss the late Holocene chironomid record from Delta Sø, whereas from Wax Lips Lake (a small, non-glacial lake situated ~2 km west of the ice sheet margin) we present a longer sedimentary and biostratigraphic record. The deeper portions of cores from Wax Lips Lake yield pre-Holocene and nonfinite radiocarbon ages, suggesting that this lake preserves sediments predating the Last Glacial Maximum. Abundant chironomids in the pre-glacial sediments appear to record interglacial conditions, and we infer that these sediments may date to the Last Interglacial (Eemian). The preservation of in situ Last Interglacial lacustrine sediments so close to the modern ice sheet margin suggests a minimally erosive glacierization style throughout the last glacial period, like that inferred for other Arctic locales such as on Baffin Island (Briner et al. 2007), ~750 km southwest of our study site. Our study sites are situated nearby key ice core sites (including NEEM, Camp Century, Agassiz and Renland) and very close to the ice sheet margin. These chironomid

Greenland was nearly ice-free for extended periods during the Pleistocene

NASA Astrophysics Data System (ADS)

Schaefer, Joerg M.; Finkel, Robert C.; Balco, Greg; Alley, Richard B.; Caffee, Marc W.; Briner, Jason P.; Young, Nicolas E.; Gow, Anthony J.; Schwartz, Roseanne

2016-12-01

The Greenland Ice Sheet (GIS) contains the equivalent of 7.4 metres of global sea-level rise. Its stability in our warming climate is therefore a pressing concern. However, the sparse proxy evidence of the palaeo-stability of the GIS means that its history is controversial (compare refs 2 and 3 to ref. 4). Here we show that Greenland was deglaciated for extended periods during the Pleistocene epoch (from 2.6 million years ago to 11,700 years ago), based on new measurements of cosmic-ray-produced beryllium and aluminium isotopes (10Be and 26Al) in a bedrock core from beneath an ice core near the GIS summit. Models indicate that when this bedrock site is ice-free, any remaining ice is concentrated in the eastern Greenland highlands and the GIS is reduced to less than ten per cent of its current volume. Our results narrow the spectrum of possible GIS histories: the longest period of stability of the present ice sheet that is consistent with the measurements is 1.1 million years, assuming that this was preceded by more than 280,000 years of ice-free conditions. Other scenarios, in which Greenland was ice-free during any or all Pleistocene interglacials, may be more realistic. Our observations are incompatible with most existing model simulations that present a continuously existing Pleistocene GIS. Future simulations of the GIS should take into account that Greenland was nearly ice-free for extended periods under Pleistocene climate forcing.

Raised BMI cut-off for overweight in Greenland Inuit--a review.

PubMed

Andersen, Stig; Fleischer Rex, Karsten; Noahsen, Paneeraq; Sørensen, Hans Christian Florian; Mulvad, Gert; Laurberg, Peter

2013-01-01

Obesity is associated with increased morbidity and premature death. Obesity rates have increased worldwide and the WHO recommends monitoring. A steep rise in body mass index (BMI), a measure of adiposity, was detected in Greenland from 1963 to 1998. Interestingly, the BMI starting point was in the overweight range. This is not conceivable in a disease-free, physically active, pre-western hunter population. This led us to reconsider the cut-off point for overweight among Inuit in Greenland. We found 3 different approaches to defining the cut-off point of high BMI in Inuit. First, the contribution to the height by the torso compared to the legs is relatively high. This causes relatively more kilograms per centimetre of height that increases the BMI by approximately 10% compared to Caucasian whites. Second, defining the cut-off by the upper 90-percentile of BMI from height and weight in healthy young Inuit surveyed in 1963 estimated the cut-off point to be around 10% higher compared to Caucasians. Third, if similar LDL-cholesterol and triglycerides are assumed for a certain BMI in Caucasians, the corresponding BMI in Inuit in both Greenland and Canada is around 10% higher. However, genetic admixture of Greenland Inuit and Caucasian Danes will influence this difference and hamper a clear distinction with time. Defining overweight according to the WHO cut-off of a BMI above 25 kg/m(2) in Greenland Inuit may overestimate the number of individuals with elevated BMI.

Solitary Waves of Ice Loss Detected in Greenland Crustal Motion

NASA Astrophysics Data System (ADS)

Adhikari, S.; Ivins, E. R.; Larour, E. Y.

2017-12-01

The annual cycle and secular trend of Greenland mass loading are well recorded in measurements of solid Earth deformation. While bedrock vertical displacements are in phase with loading as inferred from space observations, horizontal motions have received almost no attention. The horizontal bedrock displacements can potentially track the spatiotemporal detail of mass changes with great fidelity. Our analysis of Greenland crustal motion data reveals that a significant excitation of horizontal amplitudes occurs during the intense Greenland melting. A suite of space geodetic observations and climate reanalysis data cannot explain these large horizontal displacements. We discover that solitary seasonal waves of substantial mass transport traveled through Rink Glacier in 2010 and 2012. We deduce that intense summer melting enhanced either basal lubrication or shear softening, or both, causing the glacier to thin dynamically. The newly routed upstream sublglacial water was likely to be both retarded and inefficient, thus providing a causal mechanism for the prolonged ice transport to continue well into the winter months. As the climate continues to produce increasingly warmer spring and summer, amplified seasonal waves of mass transport may become ever more present in years of future observations. Increased frequency of amplified seasonal mass transport may ultimately strengthen the Greenland's dynamic ice mass loss, a component of the balance that will have important ramifications for sea level rise. This animation shows a solitary wave passing through Rink Glacier, Greenland, in 2012, recorded by the motion of a GPS station (circle with arrow). Darker blue colors within the flow indicate mass loss, red colors show mass gain. The star marks the center of the wave. Credit: NASA/JPL-Caltech

Publications - RDF 2015-5 | Alaska Division of Geological & Geophysical

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Publications - RI 2009-2 | Alaska Division of Geological & Geophysical

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Publications - RDF 2016-3 | Alaska Division of Geological & Geophysical

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Publications - RDF 2016-5 | Alaska Division of Geological & Geophysical

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Publications - RDF 2014-22 | Alaska Division of Geological & Geophysical

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Publications - RDF 2015-8 | Alaska Division of Geological & Geophysical

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from the Tonsina area, Valdez Quadrangle, Alaska: Alaska Division of Geological & Geophysical Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical

Publications - RDF 2015-16 | Alaska Division of Geological & Geophysical

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rocks collected in 2015 in the Wrangellia mineral assessment area, Alaska: Alaska Division of Geological Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical

Publications - RDF 2015-9 | Alaska Division of Geological & Geophysical

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samples from the Zane Hills, Hughes and Shungnak quadrangles, Alaska: Alaska Division of Geological & Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical

Alaska geology revealed

USGS Publications Warehouse

Wilson, Frederic H.; Labay, Keith A.

2016-11-09

This map shows the generalized geology of Alaska, which helps us to understand where potential mineral deposits and energy resources might be found, define ecosystems, and ultimately, teach us about the earth history of the State. Rock units are grouped in very broad categories on the basis of age and general rock type. A much more detailed and fully referenced presentation of the geology of Alaska is available in the Geologic Map of Alaska (http://dx.doi.org/10.3133/sim3340). This product represents the simplification of thousands of individual rock units into just 39 broad groups. Even with this generalization, the sheer complexity of Alaskan geology remains evident.

Publications - PDF 96-17 | Alaska Division of Geological & Geophysical

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Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska the Fairbanks Mining District, Alaska, scale 1:63,360 (15.0 M) Digital Geospatial Data Digital © 2010 Webmaster State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State

Publications - MP 156 | Alaska Division of Geological & Geophysical Surveys

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Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska /29446 Publication Products Report Report Information mp156.pdf (126.0 K) Digital Geospatial Data Digital State of Alaska © 2010 Webmaster State of Alaska myAlaska My Government Resident Business in Alaska

ICESat Observations of Southern Alaska Glaciers

NASA Technical Reports Server (NTRS)

Sauber, Jeanne; Molnia, Bruce F.; Mitchell, Darius

2003-01-01

In late February and March, 2003, the Ice, Cloud, and land Elevation Satellite (ICESat) measured ice and land elevations along profiles across southern Alaska. During this initial data acquisition stage ICESat observations were made on 8-day repeat tracks to enable calibration and validation of the ICESat data products. Each profile consists of a series of single point values derived from centroid elevations of an $\\approx$70 m diameter laser footprint. The points are s4pakated by $\\approx$172 m along track. Data siets of 8-day observations (an ascending and descending ground track) crossed the Bering and Malaspina Glacier. Following its 1993--1995 surge; the Bering Glacier has undergone major terminus retreat as well as ike thinning in the abtation zone. During the later part of the 20th century, parts of the Malaspina thinned by about 1 m/yr. The multiple observation profiles across the Bering and Malaspina piedmont lobes obtained in February/March are being geolocated on Landsat images and the elevation profiles will be used for a number o scientific objectives. Based on our simulations of ICESat performance over the varied ice surface of the Jakobshavn Glacier of GReenland, 2003, we expect to measure annual, and possibly seasonal, ice elevation changes on the large Alaskan glaciers. Using elevation data obtained from a second laser, we plan to estimate ice elevation changes on the Bering Glacier between March and October 2003.

Alaska Administrative Manual

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Search the Division of Finance site DOF State of Alaska Finance Home Content Area Accounting Charge Cards Administrative Manual Table of Contents Contains State of Alaska accounting/payroll policies and information clarifying accounting and payroll procedures. Policies are carried out through standard statewide procedures

Publications - GMC 410 | Alaska Division of Geological & Geophysical

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) Keywords Geochemistry; Rare Earth Elements Top of Page Department of Natural Resources, Division of Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical

Publications - GMC 409 | Alaska Division of Geological & Geophysical

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) Keywords Geochemistry; Rare Earth Elements Top of Page Department of Natural Resources, Division of Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical

Publications - GMC 183 | Alaska Division of Geological & Geophysical

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Alaska Native Education: Issues in the Nineties. Alaska Native Policy Papers.

ERIC Educational Resources Information Center

Kleinfeld, Judith

This booklet identifies several crucial problems in Alaska Native education, for example: (1) Fetal Alcohol Syndrome (FAS) and Fetal Alcohol Effects (FAE) occur in Alaska Native populations at relatively high rates and can produce mental retardation, hyperactivity, attention deficits, and learning disabilities; (2) while many Native rural school…

Homicide in Greenland 1985-2010.

PubMed

Christensen, Martin R; Thomsen, Asser H; Høyer, Christian B; Gregersen, Markil; Banner, Jytte

2016-03-01

Homicide in Greenland has not often been investigated. The latest published study documented a dramatic rise in the homicide rate from around 1/100,000 inhabitants to more than 23/100,000 inhabitants from 1946 to 1984. The aim of our study was to characterize homicides in Greenland from 1985 to 2010 and to compare trends during this period with those in previous studies and with homicide characteristics in Denmark, northern Europe, and other Arctic regions. We identified a total of 281 homicides by legal definition and 194 by medical definition, the latter from the years 1990 to 2010. We procured case files for a total of 129 victims (71 male, 58 female) and 117 perpetrators (85 male, 32 female). We identified an overall decrease in the homicide rate during our study period. The decrease in the medical homicide rate was significant (p = 0.007). The homicide rate ranged from 25/100,000 inhabitants to 13/100,000 inhabitants when results were grouped within 5-year periods. There were significantly more male perpetrators (p < 0.001) and among female perpetrators there were significantly more male victims (p < 0.001). Sharp force and gunshot-related killings dominated homicide methods (41 and 29% respectively), with sharp force deaths increasing throughout the investigation period. Altercations were the main motive (49%). Alcohol-related homicides decreased in our study period. While the Greenlandic homicide rate has decreased, it is markedly higher compared to that seen in Denmark and northern Europe. However, it resembles the rate seen in the rest of the Arctic. Liberal gun laws do not affect the proportion of gun-related killings. Despite the high homicide rate, women account for almost half the victims.

Alaska Public Offices Commission, Department of Administration, State of

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Vertical motions of passive margins of Greenland: influence of ice sheet, glacial erosion, and sediment transport

NASA Astrophysics Data System (ADS)

Souche, A.; Medvedev, S.; Hartz, E. H.

2009-04-01

The sub-ice topography of Greenland is characterized by a central depression below the sea level and by elevated (in some places significantly) margins. Whereas the central depression may be explained by significant load of the Greenland ice sheet, the origin of the peripheral relief remains unclear. We analyze the influence of formation of the ice sheet and carving by glacial erosion on the evolution of topography along the margins of Greenland. Our analysis shows that: (1) The heavy ice loading in the central part of Greenland and consecutive peripheral bulging has a negligible effect on amplitude of the uplifted Greenland margins. (2) First order estimates of uplift due to isostatic readjustment caused by glacial erosion and unloading in the fjord systems is up to 1.1 km. (3) The increase of accuracy of topographic data (comparing several data sets of resolution with grid size from 5 km to 50 m) results in increase of the isostatic response in the model. (4) The analysis of mass redistribution during erosion-sedimentation process and data on age of offshore sediments allows us to estimate the timing of erosion along the margins of Greenland. This ongoing analysis, however, requires careful account for the link between sources (localized glacial erosion) and sinks (offshore sedimentary basins around Greenland).

Prehistoric Alaska: The land

USGS Publications Warehouse

Wilson, Frederic H.; Weber, Florence R.; Rennick, Penny

1994-01-01

Many Alaskans know the dynamic nature of Alaska’s landscape firsthand. The 1964 earthquake, the 1989 eruption of Mount Redoubt volcano, the frequent earthquakes in the Aleutians and the ever-shifting meanders of the Yukon and Kuskokwim rivers remind them of constant changes to the land. These changes are part of the continuing story of the geologic growth and development of Alaska during hundreds of millions of years. By geologic time, Alaska has only recently come into existence and the dynamic processes that formed it continue to affect it. The landscape we see today has been shaped by glacier and stream erosion or their indirect effects, and to a lesser extent by volcanoes. Most prominently, if less obviously, Alaska has been built by slow movements of the Earth’s crust we call tectonic or mountain-building.During 5 billion years of geologic time, the Earth’s crust has repeatedly broken apart into plates. These plates have recombined, and have shifted positions relative to each other, to the Earth’s rotational axis and to the equator. Large parts of the Earth’s crust, including Alaska, have been built and destroyed by tectonic forces. Alaska is a collage of transported and locally formed fragments of crusts As erosion and deposition reshape the land surface, climatic changes, brought on partly by changing ocean and atmospheric circulation patterns, alter the location and extent of tropical, temperate and arctic environments. We need to understand the results of these processes as they acted upon Alaska to understand the formation of Alaska. Rocks can provide hints of previous environments because they contain traces of ocean floor and lost lands, bits and pieces of ancient history.

Publications - GMC 370 | Alaska Division of Geological & Geophysical

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(249.0 K) Keywords Rare Earth Elements Top of Page Department of Natural Resources, Division of Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical

Publications - GMC 159 | Alaska Division of Geological & Geophysical

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LearnAlaska Portal

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ESS (Employee Self Service) E-Travel Online Login IRIS FIN/PROC Login IRIS HRM Login LearnAlaska SFOA SharePoint Site TRIPS (Traveler Integrated Profile System) Vendor Self Service (VSS) Resources Alaska & Resources Manuals Payment Detail Report Salary Schedules SFOA SharePoint Site (SOA Only) Training

On the possibility of ice on Greenland during the Eocene-Oligocene transition

NASA Astrophysics Data System (ADS)

Langebroek, Petra M.; Nisancioglu, Kerim H.; Lunt, Daniel J.; Kathrine Pedersen, Vivi; Nele Meckler, A.; Gasson, Edward

2017-04-01

The Eocene-Oligocene transition ( 34 Ma) is one of the major climate transitions of the Cenozoic era. Atmospheric CO2 decreased from the high levels of the Greenhouse world (>1000 ppm) to values of about 600-700 ppm in the early Oligocene. High latitude temperatures dropped by several degrees, causing a large-scale expansion of the Antarctic ice sheet. Concurrently, in the Northern Hemisphere, the inception of ice caps on Greenland is suggested by indirect evidence from ice-rafted debris and changes in erosional regime. However, ice sheet models have not been able to simulate extensive ice on Greenland under the warm climate of the Eocene-Oligocene transition. We show that elevated bedrock topography is key in solving this inconsistency. During the late Eocene / early Oligocene, East Greenland bedrock elevations were likely higher than today due to tectonic and deep-Earth processes related to the break-up of the North Atlantic and the position of the Icelandic plume. When allowing for higher initial bedrock topography, we do simulate a large ice cap on Greenland under the still relatively warm climate of the early Oligocene. Ice inception takes place at high elevations in the colder regions of North and Northeast Greenland; with the size of the ice cap being strongly dependent on the climate forcing and the bedrock topography applied.

Deep-seated gravitational slope deformations near the Trans-Alaska Pipeline, east-central Alaska Range, Alaska, USA

NASA Astrophysics Data System (ADS)

Newman, S. D.; Clague, J. J.; Rabus, B.; Stead, D.

2013-12-01

Multiple, active, deep-seated gravitational slope deformations (DSGSD) are present near the Trans-Alaska Pipeline and Richardson Highway in the east-central Alaska Range, Alaska, USA. We documented spatial and temporal variations in rates of surface movement of the DSGSDs between 2003 and 2011 using RADARSAT-1 and RADARSAT-2 D-InSAR images. Deformation rates exceed 10 cm/month over very large areas (>1 km2) of many rock slopes. Recent climatic change and strong seismic shaking, especially during the 2002 M 7.9 Denali Fault earthquake, appear to have exacerbated slope deformation. We also mapped DSGSD geological and morphological characteristics using field- and GIS-based methods, and constructed a conceptual 2D distinct-element numerical model of one of the DSGSDs. Preliminary results indicate that large-scale buckling or kink-band slumping may be occurring. The DSGSDs are capable of generating long-runout landslides that might impact the Trans-Alaska Pipeline and Richardson Highway. They could also block tributary valleys, thereby impounding lakes that might drain suddenly. Wrapped 24-day RADARSAT-2 descending spotlight interferogram showing deformation north of Fels Glacier. The interferogram is partially transparent and is overlaid on a 2009 WorldView-1 panchromatic image. Acquisition interval: August 2 - August 26, 2011. UTM Zone 6N.

Evidence of local and regional freshening of Northeast Greenland coastal waters.

PubMed

Sejr, Mikael K; Stedmon, Colin A; Bendtsen, Jørgen; Abermann, Jakob; Juul-Pedersen, Thomas; Mortensen, John; Rysgaard, Søren

2017-10-13

The supply of freshwater to fjord systems in Greenland is increasing as a result of climate change-induced acceleration in ice sheet melt. However, insight into the marine implications of the melt water is impaired by lack of observations demonstrating the fate of freshwater along the Greenland coast and providing evaluation basis for ocean models. Here we present 13 years of summer measurements along a 120 km transect in Young Sound, Northeast Greenland and show that sub-surface coastal waters are decreasing in salinity with an average rate of 0.12 ± 0.05 per year. This is the first observational evidence of a significant freshening on decadal scale of the waters surrounding the ice sheet and comes from a region where ice sheet melt has been less significant. It implies that ice sheet dynamics in Northeast Greenland could be of key importance as freshwater is retained in southward flowing coastal currents thus reducing density of water masses influencing major deep water formation areas in the Subarctic Atlantic Ocean. Ultimately, the observed freshening could have implications for the Atlantic meridional overturning circulation.

Mapping Greenland's Firn Aquifer using L-band Microwave Radiometry

NASA Astrophysics Data System (ADS)

Miller, J.; Bringer, A.; Jezek, K. C.; Johnson, J. T.; Scambos, T. A.; Long, D. G.

2016-12-01

Greenland's recently discovered firn aquifer is one of the most interesting, yet still mysterious, components of the ice sheet system. Many open questions remain regarding timescales of refreezing and/or englacial drainage of liquid meltwater, and the connections of firn aquifers to the subglacial hydrological system. If liquid meltwater production at the surface of the Greenland ice sheet continues to increase, subsequent increases in the volume of mobile liquid meltwater retained within Greenland's firn aquifer may increase the possibility of crevasse-deepening via hydrofracture. Hydrofracture is an important component of supraglacial lake drainage leading to at least temporary accelerated flow velocities and ice sheet mass balance changes. Firn aquifers may also support hydrofracture-induced drainage and thus are potentially capable of significantly influencing ice sheet mass balance and sea level rise. Spaceborne L-band microwave radiometers provide an innovative tool for ice-sheet wide mapping of the spatiotemporal variability of Greenland's firn aquifer. Both refreezing and englacial drainage may be observable given the sensitivity of the microwave response to the upper surface of liquid meltwater retained within snow and firn pore space as well as the ability of L band instruments to probe the ice sheet from the surface to the firn-ice transition at pore close-off depth. Here we combine L-band (1.4 GHz) brightness temperature observations from multiple sources to demonstrate the potential of mapping firn aquifers on ice sheets using L-band microwave radiometry. Data sources include the interferometric MIRAS instrument aboard ESA's Soil Moisture and Ocean Salinity (SMOS) satellite mission and the radiometer aboard NASA's Soil Moisture Active Passive (SMAP) satellite mission. We will also present mulit-frequency L-band brightness temperature data (0.5-2 GHz) that will be collected over several firn aquifer areas on the Greenland ice sheet by the Ohio State

Seasonal changes in Fe along a glaciated Greenlandic fjord.

NASA Astrophysics Data System (ADS)

Hopwood, Mark; Connelly, Douglas; Arendt, Kristine; Juul-Pedersen, Thomas; Stinchcombe, Mark; Meire, Lorenz; Esposito, Mario; Krishna, Ram

2016-03-01

Greenland's ice sheet is the second largest on Earth, and is under threat from a warming Arctic climate. An increase in freshwater discharge from Greenland has the potential to strongly influence the composition of adjacent water masses with the largest impact on marine ecosystems likely to be found within the glaciated fjords. Here we demonstrate that physical and chemical estuarine processes within a large Greenlandic fjord are critical factors in determining the fate of meltwater derived nutrients and particles, especially for non-conservative elements such as Fe. Concentrations of Fe and macronutrients in surface waters along Godthåbsfjord, a southwest Greenlandic fjord with freshwater input from 6 glaciers, changed markedly between the onset and peak of the meltwater season due to the development of a thin (<10 m), outflowing, low-salinity surface layer. Dissolved (<0.2 µm) Fe concentrations in meltwater entering Godthåbsfjord (200 nM), in freshly melted glacial ice (mean 38 nM) and in surface waters close to a land terminating glacial system (80 nM) all indicated high Fe inputs into the fjord in summer. Total dissolvable (unfiltered at pH <2.0) Fe was similarly high with concentrations always in excess of 100 nM throughout the fjord and reaching up to 5.0 µM close to glacial outflows in summer. Yet, despite the large seasonal freshwater influx into the fjord, Fe concentrations near the fjord mouth in the out-flowing surface layer were similar in summer to those measured before the meltwater season. Furthermore, turbidity profiles indicated that sub-glacial particulate Fe inputs may not actually mix into the outflowing surface layer of this fjord. Emphasis has previously been placed on the possibility of increased Fe export from Greenland as meltwater fluxes increase. Here we suggest that in-fjord processes may be effective at removing Fe from surface waters before it can be exported to coastal seas.

The Greenland Ice Sheet's surface mass balance in a seasonally sea ice-free Arctic

NASA Astrophysics Data System (ADS)

Day, J. J.; Bamber, J. L.; Valdes, P. J.

2013-09-01

General circulation models predict a rapid decrease in sea ice extent with concurrent increases in near-surface air temperature and precipitation in the Arctic over the 21st century. This has led to suggestions that some Arctic land ice masses may experience an increase in accumulation due to enhanced evaporation from a seasonally sea ice-free Arctic Ocean. To investigate the impact of this phenomenon on Greenland Ice Sheet climate and surface mass balance (SMB), a regional climate model, HadRM3, was used to force an insolation-temperature melt SMB model. A set of experiments designed to investigate the role of sea ice independently from sea surface temperature (SST) forcing are described. In the warmer and wetter SI + SST simulation, Greenland experiences a 23% increase in winter SMB but 65% reduced summer SMB, resulting in a net decrease in the annual value. This study shows that sea ice decline contributes to the increased winter balance, causing 25% of the increase in winter accumulation; this is largest in eastern Greenland as the result of increased evaporation in the Greenland Sea. These results indicate that the seasonal cycle of Greenland's SMB will increase dramatically as global temperatures increase, with the largest changes in temperature and precipitation occurring in winter. This demonstrates that the accurate prediction of changes in sea ice cover is important for predicting Greenland SMB and ice sheet evolution.

Publications - MP 142 | Alaska Division of Geological & Geophysical Surveys

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Publications - SR 70 | Alaska Division of Geological & Geophysical Surveys

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Publications - MP 38 | Alaska Division of Geological & Geophysical Surveys

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Publications - SR 45 | Alaska Division of Geological & Geophysical Surveys

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Publications - MP 43 | Alaska Division of Geological & Geophysical Surveys

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Publications - MP 149 | Alaska Division of Geological & Geophysical Surveys

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Presentations - Wypych, Alicja and others, 2015 | Alaska Division of

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Geological & Geophysical Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of (AVO) Mineral Resources Alaska's Mineral Industry Reports AKGeology.info Rare Earth Elements WebGeochem

Simultaneous observations of ice motion, calving and seismicity on the Yahtse Glacier, Alaska. (Invited)

NASA Astrophysics Data System (ADS)

Larsen, C. F.; Bartholomaus, T. C.; O'Neel, S.; West, M. E.

2010-12-01

We observe ice motion, calving and seismicity simultaneously and with high-resolution on an advancing tidewater glacier in Icy Bay, Alaska. Icy Bay’s tidewater glaciers dominate regional glacier-generated seismicity in Alaska. Yahtse emanates from the St. Elias Range near the Bering-Bagley-Seward-Malaspina Icefield system, the most extensive glacier cover outside the polar regions. Rapid rates of change and fast flow (>16 m/d near the terminus) at Yahtse Glacier provide a direct analog to the disintegrating outlet systems in Greenland. Our field experiment co-locates GPS and seismometers on the surface of the glacier, with a greater network of bedrock seismometers surrounding the glacier. Time-lapse photogrammetry, fjord wave height sensors, and optical survey methods monitor iceberg calving and ice velocity near the terminus. This suite of geophysical instrumentation enables us to characterize glacier motion and geometry changes while concurrently listening for seismic energy release. We are performing a close examination of calving as a seismic source, and the associated mechanisms of energy transfer to seismic waves. Detailed observations of ice motion (GPS and optical surveying), glacier geometry and iceberg calving (direct observations and timelapse photogrammetry) have been made in concert with a passive seismic network. Combined, the observations form the basis of a rigorous analysis exploring the relationship between glacier-generated seismic events and motion, glacier-fiord interactions, calving and hydraulics. Our work is designed to demonstrate the applicability and utility of seismology to study the impact of climate forcing on calving glaciers.

Sections | Alaska Division of Geological & Geophysical Surveys

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State Employees DGGS State of Alaska search Department of Natural Resources, Division of Geological & Communications Alaska Geologic Data Index (AGDI) Volcanology Alaska Volcano Observatory (AVO) Mineral Resources Alaska MAPTEACH Tsunami Inundation Mapping Energy Resources Gas Hydrates Sponsors' Proposals STATEMAP

Metabolic syndrome: prevalence among American Indian and Alaska native people living in the southwestern United States and in Alaska.

PubMed

Schumacher, Catherine; Ferucci, Elizabeth D; Lanier, Anne P; Slattery, Martha L; Schraer, Cynthia D; Raymer, Terry W; Dillard, Denise; Murtaugh, Maureen A; Tom-Orme, Lillian

2008-12-01

Metabolic syndrome occurs commonly in the United States. The purpose of this study was to measure the prevalence of metabolic syndrome among American Indian and Alaska Native people. We measured the prevalence rates of metabolic syndrome, as defined by the National Cholesterol Education Program, among four groups of American Indian and Alaska Native people aged 20 years and older. One group was from the southwestern United States (Navajo Nation), and three groups resided within Alaska. Prevalence rates were age-adjusted to the U.S. adult 2000 population and compared to rates for U.S. whites (National Health and Nutrition Examination Survey [NHANES] 1988-1994). Among participants from the southwestern United States, metabolic syndrome was found among 43.2% of men and 47.3% of women. Among Alaska Native people, metabolic syndrome was found among 26.5% of men and 31.2% of women. In Alaska, the prevalence rate varied by region, ranging among men from 18.9% (western Alaska) to 35.1% (southeast), and among women from 22.0% (western Alaska) to 38.4 % (southeast). Compared to U.S. whites, American Indian/Alaska Native men and women from all regions except western Alaska were more likely to have metabolic syndrome; men in western Alaska were less likely to have metabolic syndrome than U.S. whites, and the prevalence among women in western Alaska was similar to that of U.S. whites. The prevalence rate of metabolic syndrome varies widely among different American Indian and Alaska Native populations. Differences paralleled differences in the prevalence rates of diabetes.

Publications - RDF 2015-7 | Alaska Division of Geological & Geophysical

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, Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the northeastern Alaska Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical

Southern Greenland water vapour isotopic composition at the crossroads of Atlantic and Arctic moisture

NASA Astrophysics Data System (ADS)

Bonne, J. L.; Steen-Larsen, H. C.; Risi, C. M.; Werner, M.; Sodemann, H.; Lacour, J. L.; Fettweis, X.; Cesana, G.; Delmotte, M.; Cattani, O.; Clerbaux, C.; Sveinbjörnsdottir, A. E.; Masson-Delmotte, V.

2014-12-01

Since September 2011, a continuous water vapour isotopic composition monitoring instrument has been remotely operated in Ivittuut (61.21°N, 48.17°W), southern Greenland. Meteorological parameters are monitored and precipitation has been sampled and analysed for isotopic composition, suggesting equilibrium between surface vapour and precipitation. The data depict small summer diurnal variations. δ18O and deuterium excess (d-excess) are generally anti-correlated and show important seasonal variations (with respective amplitudes of 10 and 20 ‰), and large synoptic variations associated to low-pressure systems (typically +5‰ on δ18O and -15‰ on d-excess). The moisture sources, estimated based on Lagrangian back-trajectories, are primarily influenced by the western North Atlantic, and north-eastern American continent. Notable are important seasonal and synoptic shifts of the moisture sources, and sporadic influences of the Arctic or the eastern North Atlantic. Moisture sources variations can be related to changes in water vapour isotopic composition, and the isotopic fingerprints can be attributed to the areas of moisture origins. Isotopic enabled AGCMs nudged to meteorology (LMDZiso, ECHAM5-wiso), despite biases, correctly capture the δ18O changes, but underestimate the d-excess changes. They allow to identify a high correlation between the southern Greenland d-excess and the simulated relative humidity and d-excess in the moisture source region south of Greenland. An extreme high temperature event in July 2012 affecting all Greenland, similar to ice sheet melt events during the medieval periods and one event in 1889 documented by Greenland ice core records, has been analysed regarding water vapour isotopic composition, using remote sensing (IASI) and in situ observations from Bermuda to northern Greenland (NEEM station). Our southern Greenland observations allow to track the water vapour evolution during this event along the moisture transport path

Meltwater-induced changes in the structure and behavior of Greenland's firn

NASA Astrophysics Data System (ADS)

MacFerrin, M. J.; Machguth, H.; van As, D.; Charalampidis, C.; Heilig, A.; Vandecrux, B.; Stevens, C.; Abdalati, W.

2017-12-01

As surface melt increases across the Greenland ice sheet in a warming climate, Greenland's accumulation zone has absorbed a progressively greater volume of water. In low-accumulation regions lacking perennial aquifers, this meltwater has refrozen into subsurface ice, which is now fundamentally altering the structure of near-surface firn layers. Here we present an extensive collection of firn cores, in situ radar, NASA IceBridge radar, thermistor string measurements, in situ FirnCover compaction data and regional climate model results to illustrate several distinct ways that Greenland's percolation zone is being fundamentally altered by increasing surface melt. The bulk density of the top 20 meters' firn in the wet-snow facies has increased by up to 40% in the past 50 years, due primarily to an up to six-fold increase in firn ice content. Firn compaction rates have changed both in their annual magnitude and have been delayed in their seasonal phase by up to three months, driven primarily by an increased release of latent heat as water refreezes at depth. When firn exceeds a threshold of excess melt in which seasonal snow can no longer accommodate summer melt, individual refrozen ice layers at depth have annealed together to form low-permeability ice slabs (LPISs). These multi-meter thick layers of ice perched over porous firn block percolation to depth and increase the size of the runoff zone. LPISs are a type of "hybrid facies" capable both of running water off the surface, while continuing to slowly compact porous firn at depth. Currently LPISs cover approximately 5% of Greenland's current accumulation zone, but we project them to extend across 15-50% of the accumulation zone by 2100 under different forcing scenarios. These observed changes in the structure and behavior of Greenland's firn have serious implications for future runoff of the ice sheet. Additionally, they challenge modern assumptions which we use to quantify the mass balance of the Greenland ice

Presentations - Twelker, Evan and others, 2014 | Alaska Division of

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magmatic Ni-Cu-Co-PGE system in the Talkeetna Mountains, central Alaska (poster): Society of Economic Geological & Geophysical Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of

Baffin Island and West Greenland Current Systems in northern Baffin Bay

NASA Astrophysics Data System (ADS)

Münchow, Andreas; Falkner, Kelly K.; Melling, Humfrey

2015-03-01

Temperature, salinity, and direct velocity observations from northern Baffin Bay are presented from a summer 2003 survey. The data reveal interactions between fresh and cold Arctic waters advected southward along Baffin Island and salty and warm Atlantic waters advected northward along western Greenland. Geostrophic currents estimated from hydrography are compared to measured ocean currents above 600 m depth. The Baffin Island Current is well constrained by the geostrophic thermal wind relation, but the West Greenland Current is not. Furthermore, both currents are better described as current systems that contain multiple velocity cores and eddies. We describe a surface-intensified Baffin Island Current seaward of the continental slope off Canada and a bottom-intensified West Greenland Current over the continental slope off Greenland. Acoustic Doppler current profiler observations suggest that the West Greenland Current System advected about 3.8 ± 0.27 Sv (Sv = 106 m3 s-1) towards the north-west at this time. The most prominent features were a surface intensified coastal current advecting 0.5 Sv and a bottom intensified slope current advecting about 2.5 Sv in the same direction. Most of this north-westward circulation turned southward in the Baffin Island Current System. The Baffin Island system was transporting 5.1 ± 0.24 Sv to the south-east at the time that includes additional contributions from Nares Strait to the north (1.0 ± 0.2 Sv) and Lancaster Sound to the east (1.0 ± 0.2 Sv). Net freshwater fluxes were 72 and 187 mSv for the West Greenland and Baffin Island Currents, respectively. Empirical uncertainty arises from unknown temporal variations at weekly time scales and pertubations introduced by unresolved eddies. Eddies with 10 km horizontal and 400 m vertical scales were common and recirculated up to 1 Sv. Our 2003 observations represent conditions when the North-Atlantic Oscillation index (NAO) was close to zero. Analysis of historical hydrographic

Annual Greenland Accumulation Rates (2009-2012) from Airborne Snow Radar

NASA Technical Reports Server (NTRS)

Koenig, Lora S.; Ivanoff, Alvaro; Alexander, Patrick M.; MacGregor, Joseph A.; Fettweis, Xavier; Panzer, Ben; Paden, John D.; Forster, Richard R.; Das, Indrani; McConnell, Joseph R.;

Pb concentrations and isotopic record preserved in northwest Greenland snow.

PubMed

Kang, Jung-Ho; Hwang, Heejin; Han, Changhee; Hur, Soon Do; Kim, Seong-Joong; Hong, Sungmin

2017-11-01

We present high-resolution lead (Pb) concentrations and isotopic ratios from a northwest Greenland snow pit covering a six-year period between 2003 and 2009. Pb concentrations ranged widely from 2.7 pg g -1 to 97.3 pg g -1 , with a mean concentration of 21.6 pg g -1 . These values are higher than those recorded for the pre-industrial period. Pb concentrations exhibit seasonal spikes in winter-spring layers. Crustal Pb enrichment factors (EF) suggest that the northwest Greenland snow pit is highly enriched with Pb of predominantly anthropogenic origin. The 206 Pb/ 207 Pb ratios ranged from 1.144 to 1.169 with a mean value of 1.156, which fall between less radiogenic Eurasian-type and more radiogenic Canadian-type signatures. This result suggests that several potential source areas of Pb impact on northwest Greenland. Abrupt changes in Pb concentrations and Pb isotope ratios were observed and related to seasonal shifts in source regions of aerosol transport. The 206 Pb/ 207 Pb isotope ratio increased gradually between 2003 and 2009. The similarity of the three-isotope plot ( 206 Pb/ 207 Pb versus 208 Pb/ 207 Pb) between some of our samples and Chinese urban aerosols suggests a steadily increasing contribution of Chinese Pb to northwest Greenland snow. Copyright © 2017. Published by Elsevier Ltd.

Bedrock geologic map of the northern Alaska Peninsula area, southwestern Alaska

USGS Publications Warehouse

Wilson, Frederic H.; Blodgett, Robert B.; Blome, Charles D.; Mohadjer, Solmaz; Preller, Cindi C.; Klimasauskas, Edward P.; Gamble, Bruce M.; Coonrad, Warren L.

2017-03-03

The northern Alaska Peninsula is a region of transition from the classic magmatic arc geology of the Alaska Peninsula to a Proterozoic and early Paleozoic carbonate platform and then to the poorly understood, tectonically complex sedimentary basins of southwestern Alaska. Physiographically, the region ranges from the high glaciated mountains of the Alaska-Aleutian Range to the coastal lowlands of Cook Inlet on the east and Bristol Bay on the southwest. The lower Ahklun Mountains and finger lakes on the west side of the map area show strong effects from glaciation. Structurally, a number of major faults cut the map area. Most important of these are the Bruin Bay Fault that parallels the coast of Cook Inlet, the Lake Clark Fault that cuts diagonally northeast to southwest across the eastern part of the map area, and the presently active Holitna Fault to the northwest that cuts surficial deposits.Distinctive rock packages assigned to three provinces are overlain by younger sedimentary rocks and intruded by widely dispersed latest Cretaceous and (or) early Tertiary granitic rocks. Much of the east half of the map area lies in the Alaska-Aleutian Range province; the Jurassic to Tertiary Alaska-Aleutian Range batholith and derivative Jurassic sedimentary rocks form the core of this province, which is intruded and overlain by the Aleutian magmatic arc. The Lime Hills province, the carbonate platform, occurs in the north-central part of the map area. The Paleozoic and Mesozoic Ahklun Mountains province in the western part of the map area includes abundant chert, argillite, and graywacke and lesser limestone, basalt, and tectonic mélange. The Kuskokwim Group, an Upper Cretaceous turbidite sequence, is extensively exposed and bounds all three provinces in the west-central part of the map area.

76 FR 81247 - Fisheries of the Exclusive Economic Zone Off Alaska; Groundfish of the Gulf of Alaska; Amendment 88

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-27

... Atmospheric Administration 50 CFR Part 679 Fisheries of the Exclusive Economic Zone Off Alaska; Groundfish of... Exclusive Economic Zone Off Alaska; Groundfish of the Gulf of Alaska; Amendment 88 AGENCY: National Marine... conservation, management, safety, and economic gains realized under the Central Gulf of Alaska Rockfish Pilot...

78 FR 11988 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-21

...-management process involving the Service, the Alaska Department of Fish and Game, and Alaska Native... developed under a co-management process involving the Service, the Alaska Department of Fish and Game, and... Fish and Game's request to expand the Fairbanks North Star Borough excluded area to include the Central...

Wood and fish residuals composting in Alaska

Treesearch

David Nicholls; Thomas Richard; Jesse A. Micales

2002-01-01

The unique climates and industrial mix in southeast and south central Alaska are challenges being met by the region's organics recyclers. OMPOSTING wood residuals in Alaska has become increasingly important in recent years as wood processors and other industrial waste managers search for environmentally sound and profitable outlets. Traditionally, Alaska?s...

Dental caries in rural Alaska Native children--Alaska, 2008.

PubMed

2011-09-23

In April 2008, the Arctic Investigations Program (AIP) of CDC was informed by the Alaska Department of Health and Social Services (DHSS) of a large number of Alaska Native (AN) children living in a remote region of Alaska who required full mouth dental rehabilitations (FMDRs), including extractions and/or restorations of multiple carious teeth performed under general anesthesia. In this remote region, approximately 400 FMDRs were performed in AN children aged <6 years in 2007; the region has approximately 600 births per year. Dental caries can cause pain, which can affect children's normal growth and development. AIP and Alaska DHSS conducted an investigation of dental caries and associated risk factors among children in the remote region. A convenience sample of children aged 4-15 years in five villages (two with fluoridated water and three without) was examined to estimate dental caries prevalence and severity. Risk factor information was obtained by interviewing parents. Among children aged 4-5 years and 12-15 years who were evaluated, 87% and 91%, respectively, had dental caries, compared with 35% and 51% of U.S. children in those age groups. Among children from the Alaska villages, those aged 4-5 years had a mean of 7.3 dental caries, and those aged 12-15 years had a mean of 5.0, compared with 1.6 and 1.8 dental caries in same-aged U.S. children. Of the multiple factors assessed, lack of water fluoridation and soda pop consumption were significantly associated with dental caries severity. Collaborations between tribal, state, and federal agencies to provide effective preventive interventions, such as water fluoridation of villages with suitable water systems and provision of fluoride varnishes, should be encouraged.

Conceptualizing and contextualizing food insecurity among Greenlandic children

PubMed Central

Niclasen, Birgit; Molcho, Michal; Arnfjord, Steven; Schnohr, Christina

2013-01-01

Objective To review the context of food insecurity in Greenlandic children, to review and compare the outcomes related to food insecurity in Greenlandic children, in other Arctic child populations and in other western societies, and to explore the measure used by the Health Behaviour in School-aged Children (HBSC) study. Design The study includes literature reviews, focus group interviews with children and analyses of data from the HBSC study. HBSC is an international cross-national school-based survey on child and adolescent health and health behaviour in the age groups 11, 13 and 15 years and performed in more than 40 countries. The item on food insecurity is “Some young people go to school or to bed hungry because there is not enough food in the home. How often does this happen to you?” (with the response options: “Always”, “Often”, “Sometimes”, or “Never”). Results The context to food security among Inuit in Arctic regions was found to be very similar and connected to a westernization of the diet and contamination of the traditional diet. The major challenges are contamination, economic access to healthy food and socio-demographic differences in having a healthy diet. The literature on outcomes related to food insecurity in children in Western societies was reviewed and grouped based on 8 domains. Using data from the Greenlandic HBSC data from 2010, the item on food security showed negative associations on central items in all these domains. Focus group interviews with children revealed face and content validity of the HBSC item. Conclusion Triangulation of the above-mentioned findings indicates that the HBSC measure of food shortage is a reliable indicator of food insecurity in Greenlandic schoolchildren. However, more research is needed, especially on explanatory and mediating factors. PMID:23687639

Regional and Local Glacial-Earthquake Patterns in Greenland

NASA Astrophysics Data System (ADS)

Olsen, K.; Nettles, M.

2016-12-01

Icebergs calved from marine-terminating glaciers currently account for up to half of the 400 Gt of ice lost annually from the Greenland ice sheet (Enderlin et al., 2014). When large capsizing icebergs ( 1 Gt of ice) calve, they produce elastic waves that propagate through the solid earth and are observed as teleseismically detectable MSW 5 glacial earthquakes (e.g., Ekström et al., 2003; Nettles & Ekström, 2010 Tsai & Ekström, 2007; Veitch & Nettles, 2012). The annual number of these events has increased dramatically over the past two decades. We analyze glacial earthquakes from 2011-2013, which expands the glacial-earthquake catalog by 50%. The number of glacial-earthquake solutions now available allows us to investigate regional patterns across Greenland and link earthquake characteristics to changes in ice dynamics at individual glaciers. During the years of our study Greenland's west coast dominated glacial-earthquake production. Kong Oscar Glacier, Upernavik Isstrøm, and Jakobshavn Isbræ all produced more glacial earthquakes during this time than in preceding years. We link patterns in glacial-earthquake production and cessation to the presence or absence of floating ice tongues at glaciers on both coasts of Greenland. The calving model predicts glacial-earthquake force azimuths oriented perpendicular to the calving front, and comparisons between seismic data and satellite imagery confirm this in most instances. At two glaciers we document force azimuths that have recently changed orientation and confirm that similar changes have occurred in the calving-front geometry. We also document glacial earthquakes at one previously quiescent glacier. Consistent with previous work, we model the glacial-earthquake force-time function as a boxcar with horizontal and vertical force components that vary synchronously. We investigate limitations of this approach and explore improvements that could lead to a more accurate representation of the glacial earthquake source.

Publications - GMC 53C | Alaska Division of Geological & Geophysical

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Alaska's Mineral Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska Paleozoic through Tertiary sandstones, North Slope, Alaska Authors: Alaska Research Associates Publication through Tertiary sandstones, North Slope, Alaska: Alaska Division of Geological & Geophysical Surveys

Cultural adaptation, compounding vulnerabilities and conjunctures in Norse Greenland.

PubMed

Dugmore, Andrew J; McGovern, Thomas H; Vésteinsson, Orri; Arneborg, Jette; Streeter, Richard; Keller, Christian

2012-03-06

Norse Greenland has been seen as a classic case of maladaptation by an inflexible temperate zone society extending into the arctic and collapse driven by climate change. This paper, however, recognizes the successful arctic adaptation achieved in Norse Greenland and argues that, although climate change had impacts, the end of Norse settlement can only be truly understood as a complex socioenvironmental system that includes local and interregional interactions operating at different geographic and temporal scales and recognizes the cultural limits to adaptation of traditional ecological knowledge. This paper is not focused on a single discovery and its implications, an approach that can encourage monocausal and environmentally deterministic emphasis to explanation, but it is the product of sustained international interdisciplinary investigations in Greenland and the rest of the North Atlantic. It is based on data acquisitions, reinterpretation of established knowledge, and a somewhat different philosophical approach to the question of collapse. We argue that the Norse Greenlanders created a flexible and successful subsistence system that responded effectively to major environmental challenges but probably fell victim to a combination of conjunctures of large-scale historic processes and vulnerabilities created by their successful prior response to climate change. Their failure was an inability to anticipate an unknowable future, an inability to broaden their traditional ecological knowledge base, and a case of being too specialized, too small, and too isolated to be able to capitalize on and compete in the new protoworld system extending into the North Atlantic in the early 15th century.

Interdisciplinary Graduate Training in Polar Environmental Change: Field-based learning in Greenland

NASA Astrophysics Data System (ADS)

Virginia, R. A.; Holm, K.; Whitecloud, S.; Levy, L.; Kelly, M. A.; Feng, X.; Grenoble, L.

2009-12-01

The objective of the NSF-funded Integrative Graduate Education Research Traineeship (IGERT) program at Dartmouth College is to develop a new cohort of environmental scientists and engineers with an interdisciplinary understanding of polar regions and their importance to global environmental change. The Dartmouth IGERT challenges Ph.D. students to consider the broader dimensions of their research and to collaborate with scientists from other disciplines, educators, and policy makers. IGERT students will focus on research questions that are relevant to the needs of local people experiencing climate change and on understanding the ethical responsibilities and benefits of conducting research in partnership with northern residents and institutions. Seven Ph.D. students from the departments of Earth Sciences, Engineering, and Ecology and Evolutionary Biology at Dartmouth College make up the first IGERT cohort for the five-year program. The Dartmouth IGERT curriculum will focus on three main components of polar systems responding to recent climate change: the cryosphere, terrestrial ecosystems, and biogeochemical cycles. The integrating experience of the core curriculum is the Greenland Field Seminar that will take place in Kangerlussuaq (terrestrial and aquatic systems), Summit Camp (snow and ice) and Nuuk, Greenland (human dimensions of change). In Nuuk, IGERT students will share their science and develop partnerships with students, educators, and policy makers at the University of Greenland, the Inuit Circumpolar Council (ICC), and other Greenlandic institutions. In summer 2009 the authors conducted preliminary fieldwork near Kangerlussuaq, Greenland to develop aspects of the science curriculum for the 2010 Greenland Field Seminar and to explore research topics for IGERT Fellows (Levy and Whitecloud). Examples of results presented here are designed to develop field-based learning activities. These include soil and vegetation relationships as a function of aspect

Publications - MP 150 | Alaska Division of Geological & Geophysical Surveys

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Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska larger work. Please see DDS 3 for more information. Digital Geospatial Data Digital Geospatial Data Business in Alaska Visiting Alaska State Employees

Publications - RI 2011-4 | Alaska Division of Geological & Geophysical

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Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska district, Circle Quadrangle, Alaska, scale 1:50,000 (16.0 M) Digital Geospatial Data Digital Geospatial Business in Alaska Visiting Alaska State Employees

Complex Greenland outlet glacier flow captured

PubMed Central

Aschwanden, Andy; Fahnestock, Mark A.; Truffer, Martin

2016-01-01

The Greenland Ice Sheet is losing mass at an accelerating rate due to increased surface melt and flow acceleration in outlet glaciers. Quantifying future dynamic contributions to sea level requires accurate portrayal of outlet glaciers in ice sheet simulations, but to date poor knowledge of subglacial topography and limited model resolution have prevented reproduction of complex spatial patterns of outlet flow. Here we combine a high-resolution ice-sheet model coupled to uniformly applied models of subglacial hydrology and basal sliding, and a new subglacial topography data set to simulate the flow of the Greenland Ice Sheet. Flow patterns of many outlet glaciers are well captured, illustrating fundamental commonalities in outlet glacier flow and highlighting the importance of efforts to map subglacial topography. Success in reproducing present day flow patterns shows the potential for prognostic modelling of ice sheets without the need for spatially varying parameters with uncertain time evolution. PMID:26830316

Explicit Simulation of Networks of Outlet Glaciers to Constrain Greenland's Sea Level Contribution

NASA Astrophysics Data System (ADS)

Ultee, E.; Bassis, J. N.

2017-12-01

Ice from the Greenland Ice Sheet drains to the ocean through hundreds of outlet glaciers, many of which are too small to be accurately resolved in continental-scale ice sheet models. Moreover, despite the fact that dynamic changes in Greenland outlet glaciers are currently responsible for about half of the ice sheet's contribution to global sea level, all but the largest are often excluded from major sea level assessments. We have previously developed and validated a simple model that simulates advance and retreat of networks of marine-terminating glaciers based on the perfect plastic approximation. Here we apply this model to a selection of forcing scenarios, representing both climate persistence and extreme scenarios, to constrain changes in calving flux from the most significant Greenland outlet glaciers. Our model can be implemented in standalone mode or as the calving module in a more sophisticated large-scale model, providing constraints on Greenland's future contribution to global sea level rise under a range of scenarios.

High geothermal heat flux in close proximity to the Northeast Greenland Ice Stream.

PubMed

Rysgaard, Søren; Bendtsen, Jørgen; Mortensen, John; Sejr, Mikael K

2018-01-22

The Greenland ice sheet (GIS) is losing mass at an increasing rate due to surface melt and flow acceleration in outlet glaciers. Currently, there is a large disagreement between observed and simulated ice flow, which may arise from inaccurate parameterization of basal motion, subglacial hydrology or geothermal heat sources. Recently it was suggested that there may be a hidden heat source beneath GIS caused by a higher than expected geothermal heat flux (GHF) from the Earth's interior. Here we present the first direct measurements of GHF from beneath a deep fjord basin in Northeast Greenland. Temperature and salinity time series (2005-2015) in the deep stagnant basin water are used to quantify a GHF of 93 ± 21 mW m -2 which confirm previous indirect estimated values below GIS. A compilation of heat flux recordings from Greenland show the existence of geothermal heat sources beneath GIS and could explain high glacial ice speed areas such as the Northeast Greenland ice stream.

Publications - AR 2010 | Alaska Division of Geological & Geophysical

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Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical DGGS AR 2010 Publication Details Title: Alaska Division of Geological & Geophysical Surveys Annual Report Authors: DGGS Staff Publication Date: Jan 2011 Publisher: Alaska Division of Geological &

Publications - RI 2009-3 | Alaska Division of Geological & Geophysical

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Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska , northeastern Brooks Range, Alaska, scale 1:63,360 (129.0 M) Digital Geospatial Data Digital Geospatial Data Resident Business in Alaska Visiting Alaska State Employees

Alaska State Legislature

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The Alaska State Legislature search menu Home Senate Current Members Past Members By Session search Home Get Started About the Legislative Branch Legislative Branch The Legislative Branch is responsible for enacting the laws of the State of Alaska and appropriating the money necessary to operate the

Digestive enzyme activities of turbot (Scophthalmus maximus L.) during early developmental stages under culture condition.

PubMed

Tong, X H; Xu, S H; Liu, Q H; Li, J; Xiao, Z Z; Ma, D Y

2012-06-01

Digestive enzyme activities were analysed in turbot (Scophthalmus maximus) from hatching until 60 days after hatching (DAH). Trypsin sharply increased to the climax at 17 DAH and decreased until 31 DAH followed by a stable level thereafter. Amylase was determined at 4 DAH, reached the maximum value at 19 DAH and declined sharply to 39 DAH and remained at a low level thereafter, suggesting the carbohydrate component should remain at a low level in formulated diets. Pepsin was detected at 9 DAH and increased to 34 DAH and then remained at a stable level. The above results revealed pancreatic enzymes are no longer main enzymes for food digestion after the formation of functional stomach. Leucine-alanine peptidase (Leu-ala) and alkaline phosphatase (AP) and leucine aminopeptidase N (LAP) were found in newly hatched larvae. Both AP and LAP activities markedly increased to 23 DAH, decreased abruptly to 50 DAH and increased gradually to 60 DAH. Leu-ala reached the plateau from 23 to 39 DAH, followed by a decline to 46 DAH and an increase until 60 DAH. The brush border membrane (BBM)-bound enzyme activities increased from 30% at 31 DAH to 81% at 38 DAH of the total activities, indicating the maturation of intestinal tract.

Trends of perfluorochemicals in Greenland ringed seals and polar bears: indications of shifts to decreasing trends.

PubMed

Rigét, Frank; Bossi, Rossana; Sonne, Christian; Vorkamp, Katrin; Dietz, Rune

2013-11-01

Time-series of perfluorinated alkylated substances (PFASs) in East Greenland polar bears and East and West Greenland ringed seals were updated in order to deduce whether a response to the major reduction in perfluoroalkyl production in the early 2000s had occurred. Previous studies had documented an exponential increase of perfluorooctane sulphonate (PFOS) in liver tissue from both species. In the present study, PFOS was still the far most dominant compound constituting 92% (West Greenland ringed seals), 88% (East Greenland ringed seals) and 85% (East Greenland polar bears). The PFOS concentrations increased up to 2006 with doubling times of approximately 6 years for the ringed seal populations and 14 years in case of polar bears. Since then a rapid decrease has occurred with clearing half-lives of approximately 1, 2 and 4 years, respectively. In polar bears perfluorohexane sulphonate (PFHxS) and perfluorooctane sulphonamide (PFOSA) also showed decreasing trends in recent years as do perfluorodecanoic acid (PFDA) and perfluoroundecanoic acid (PFUnA). For the West Greenland ringed seal population perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), PFDA and PFUnA peaked in the mid 2000s, whereas PFNA, PFDA and PFUnA in the East Greenland population have been stable or increasing in recent years. The peak of PFASs in Greenland ringed seals and polar bears occurred at a later time than in Canadian seals and polar bears and considerably later than observed in seal species from more southern latitudes. We suggest that this could be explained by the distance to emission hot-spots and differences in long-range transport to the Arctic. Copyright © 2013 Elsevier Ltd. All rights reserved.

Spatiotemporal Variability of Meltwater Refreezing in Southwest Greenland Ice Sheet Firn

NASA Astrophysics Data System (ADS)

Rennermalm, A. K.; Hock, R.; Tedesco, M.; Corti, G.; Covi, F.; Miège, C.; Kingslake, J.; Leidman, S. Z.; Munsell, S.

2017-12-01

A substantial fraction of the summer meltwater formed on the surface of the Greenland ice sheet is retained in firn, while the remaining portion runs to the ocean through surface and subsurface channels. Refreezing of meltwater in firn can create impenetrable ice lenses, hence being a crucial process in the redistribution of surface runoff. To quantify the impact of refreezing on runoff and current and future Greenland surface mass balance, a three year National Science Foundation funded project titled "Refreezing in the firn of the Greenland ice sheet: Spatiotemporal variability and implications for ice sheet mass balance" started this past year. Here we present an overview of the project and some initial results from the first field season in May 2017 conducted in proximity of the DYE-2 site in the percolation zone of the Southwest Greenland ice sheet at elevations between 1963 and 2355 m a.s.l.. During this fieldwork two automatic weather stations were deployed, outfitted with surface energy balance sensors and 16 m long thermistor strings, over 300 km of ground penetrating radar data were collected, and five 20-26 m deep firn cores were extracted and analyzed for density and stratigraphy. Winter snow accumulation was measured along the radar tracks. Preliminary work on the firn-core data reveals increasing frequency and thickness of ice lenses at lower ice-sheet elevations, in agreement with other recent work in the area. Data collected within this project will facilitate advances in our understanding of the spatiotemporal variability of firn refreezing and its role in the hydrology and surface mass balance of the Greenland Ice Sheet.

Alaska Workforce Investment Board

Science.gov Websites

! Looking for a job? Click here. About Us Board Member Documents Phone: (907) 269-7485 Toll Free: (888) 412 : 907-269-7485 Toll Free: 888-412-4742 Fax: 907-269-7489 State of Alaska myAlaska My Government Resident

The evolving Alaska mapping program.

USGS Publications Warehouse

Brooks, P.D.; O'Brien, T. J.

1986-01-01

This paper describes the development of mapping in Alaska, the current status of the National Mapping Program, and future plans for expanding and improving the mapping coverage. Research projects with Landsat Multispectral Scanner and Return Vidicon imagery and real- and synthetic-aperture radar; image mapping programs; digital mapping; remote sensing projects; the Alaska National Interest Lands Conservation Act; and the Alaska High-Altitude Aerial Photography Program are also discussed.-from Authors

Oceanic Transport of Surface Meltwater from the Southern Greenland Ice Sheet

NASA Technical Reports Server (NTRS)

Luo, Hao; Castelao, Renato M.; Rennermalm, Asa K.; Tedesco, Marco; Bracco, Annalisa; Yager, Patricia L.; Mote, Thomas L.

2016-01-01

The Greenland ice sheet has undergone accelerating mass losses during recent decades. Freshwater runoff from ice melt can influence fjord circulation and dynamic1 and the delivery of bioavailable micronutrients to the ocean. It can also have climate implications, because stratification in the adjacent Labrador Sea may influence deep convection and the strength of the Atlantic meridional overturning circulation. Yet, the fate of the meltwater in the ocean remains unclear. Here, we use a high-resolution ocean model to show that only 1-15% of the surface meltwater runoff originating from southwest Greenland is transported westwards. In contrast, up to 50-60% of the meltwater runoff originating from southeast Greenland is transported westwards into the northern Labrador Sea, leading to significant salinity and stratification anomalies far from the coast. Doubling meltwater runoff, as predicted in future climate scenarios, results in a more-than-double increase in anomalies offshore that persists further into the winter. Interannual variability in offshore export of meltwater is tightly related to variability in wind forcing. The new insight that meltwaters originating from the west and east coasts have different fates indicates that future changes in mass loss rates and surface runoff will probably impact the ocean differently, depending on their Greenland origins.

Publications - GMC 16 | Alaska Division of Geological & Geophysical Surveys

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Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska Geologic Data Index (AGDI) Volcanology Alaska Volcano Observatory (AVO) Mineral Resources Alaska's Mineral and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a

Publications - RDF 2010-2 | Alaska Division of Geological & Geophysical

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Prospect; Trace Elements; Trace Metals; Triassic; Wrangellia Terrane; geoscientificInformation Top of Page Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical

Publications - RDF 2015-6 | Alaska Division of Geological & Geophysical

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Sediments; Trace Elements; Trace Geochemical; Trace Metals; geoscientificInformation Top of Page Department Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical

Alaska Natives assessing the health of their environment.

PubMed

Garza, D

2001-11-01

The changes in Alaska's ecosystems caused by pollution, contaminants and global climate change are negatively impacting Alaska Natives and rural residents who rely on natural resources for food, culture and community identity. While Alaska commerce has contributed little to these global changes and impacts, Alaska and its resources are nonetheless affected by the changes. While Alaska Natives have historically relied on Alaska's land, water and animals for survival and cultural identity, today their faith in the safety and quality of these resources has decreased. Alaska Natives no longer believe that these wild resources are the best and many are turning to alternative store-bought foods. Such a change in diet and activity may be contributing to a decline in traditional activities and a decline in general health. Contaminants are showing up in the animals, fish and waters that Alaska Natives use. Efforts need to be expanded to empower Alaska Native Tribes to collect and analyze local wild foods for various contaminants. In addition existing information on contaminants and pollution should be made readily available to Alaska residents. Armed with this type of information Alaska Native residents will be better prepared to make informed decisions on using wild foods and materials.

Publications - GMC 171 | Alaska Division of Geological & Geophysical

Science.gov Websites

Arco Alaska Inc. Delta State #2 well Authors: Pawlewicz, Mark Publication Date: 1990 Publisher: Alaska , Vitrinite reflectance data of cuttings (3270'-10760') from the Arco Alaska Inc. Delta State #2 well: Alaska

Publications - RDF 2012-3 | Alaska Division of Geological & Geophysical

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Assessment Project; Trace Elements; geoscientificInformation Top of Page Department of Natural Resources Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical

Publications - RDF 2005-4 | Alaska Division of Geological & Geophysical

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District; Trace Elements; Trace Metals; Tungsten; Uranium; Vanadium; Yttrium; Zinc; Zirconium Top of Page Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical

Publications - RDF 2016-2 | Alaska Division of Geological & Geophysical

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, Major-oxide and trace-element geochemistry of mafic rocks in the Carboniferous Lisburne Group, Ivishak Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical

Publications - RDF 2000-4 | Alaska Division of Geological & Geophysical

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Oxides; Palladium; Platinum; Rare Earth Elements; STATEMAP Project; Trace Metals Top of Page Department Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical

Trends in Alaska's People and Economy.

ERIC Educational Resources Information Center

Leask, Linda; Killorin, Mary; Martin, Stephanie

This booklet provides data on Alaska's population, economy, health, education, government, and natural resources, including specific information on Alaska Natives. Since 1960, Alaska's population has tripled and become more diverse, more stable, older, less likely to be male or married, and more concentrated. About 69 percent of the population…

Peopling of the North Circumpolar Region--insights from Y chromosome STR and SNP typing of Greenlanders.

PubMed

Olofsson, Jill Katharina; Pereira, Vania; Børsting, Claus; Morling, Niels

2015-01-01

The human population in Greenland is characterized by migration events of Paleo- and Neo-Eskimos, as well as admixture with Europeans. In this study, the Y-chromosomal variation in male Greenlanders was investigated in detail by typing 73 Y-chromosomal single nucleotide polymorphisms (Y-SNPs) and 17 Y-chromosomal short tandem repeats (Y-STRs). Approximately 40% of the analyzed Greenlandic Y chromosomes were of European origin (I-M170, R1a-M513 and R1b-M343). Y chromosomes of European origin were mainly found in individuals from the west and south coasts of Greenland, which is in agreement with the historic records of the geographic placements of European settlements in Greenland. Two Inuit Y-chromosomal lineages, Q-M3 (xM19, M194, L663, SA01 and L766) and Q-NWT01 (xM265) were found in 23% and 31% of the male Greenlanders, respectively. The time to the most recent common ancestor (TMRCA) of the Q-M3 lineage of the Greenlanders was estimated to be between 4,400 and 10,900 years ago (y. a.) using two different methods. This is in agreement with the theory that the North Circumpolar Region was populated via a second expansion of humans in the North American continent. The TMRCA of the Q-NWT01 (xM265) lineage in Greenland was estimated to be between 7,000 and 14,300 y. a. using two different methods, which is older than the previously reported TMRCA of this lineage in other Inuit populations. Our results indicate that Inuit individuals carrying the Q-NWT01 (xM265) lineage may have their origin in the northeastern parts of North America and could be descendants of the Dorset culture. This in turn points to the possibility that the current Inuit population in Greenland is comprised of individuals of both Thule and Dorset descent.

Alaska Native Participation in the Civilian Conservation Corps. Alaska Historical Commission Studies in History No. 206.

ERIC Educational Resources Information Center

Sorensen, Connor; And Others

The report is a finding aid to the sources which document the 1937 federal policy decision mandating that 50% of the enrollees in the Civilian Conservation Corps (CCC) in Alaska must be Alaska Natives and provides a list of the Native CCC projects in Alaska. The finding aid section is organized according to the location of the collections and…

78 FR 4435 - BLM Director's Response to the Alaska Governor's Appeal of the BLM Alaska State Director's...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-22

... Bureau of Land Management (BLM) is publishing this notice to explain why the BLM Director is rejecting... Director's Response to the Alaska Governor's Appeal of the BLM Alaska State Director's Governor's... the BLM Alaska State Director. The State Director determined the Governor's Finding was outside the...

Publications - SR 37 | Alaska Division of Geological & Geophysical Surveys

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Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska Section; Resource Assessment; Tyonek Formation; Type Section Top of Page Department of Natural Resources State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Surveys Home

Presentations - Twelker, Evan and others, 2014 | Alaska Division of

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Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Details Title: Preliminary results from 2014 geologic mapping in the Talkeetna Mountains, Alaska Lande, Lauren, 2014, Preliminary results from 2014 geologic mapping in the Talkeetna Mountains, Alaska

Publications - RDF 2004-2 | Alaska Division of Geological & Geophysical

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; Trace Elements; Trace Metals; Tungsten; Vanadium; Yttrium; Zinc; Zirconium Top of Page Department of Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical

Publications - SR 32 | Alaska Division of Geological & Geophysical Surveys

Science.gov Websites

DGGS SR 32 Publication Details Title: Oil and gas basins map of Alaska Authors: Ehm, Arlen Publication ): Alaska Statewide Bibliographic Reference Ehm, Arlen, 1983, Oil and gas basins map of Alaska: Alaska Sheets Sheet 1 Oil and gas basins map of Alaska, scale 1:2,500,000 (21.0 M) Keywords Alaska Statewide

Holocene deceleration of the Greenland Ice Sheet.

PubMed

MacGregor, Joseph A; Colgan, William T; Fahnestock, Mark A; Morlighem, Mathieu; Catania, Ginny A; Paden, John D; Gogineni, S Prasad

2016-02-05

Recent peripheral thinning of the Greenland Ice Sheet is partly offset by interior thickening and is overprinted on its poorly constrained Holocene evolution. On the basis of the ice sheet's radiostratigraphy, ice flow in its interior is slower now than the average speed over the past nine millennia. Generally higher Holocene accumulation rates relative to modern estimates can only partially explain this millennial-scale deceleration. The ice sheet's dynamic response to the decreasing proportion of softer ice from the last glacial period and the deglacial collapse of the ice bridge across Nares Strait also contributed to this pattern. Thus, recent interior thickening of the Greenland Ice Sheet is partly an ongoing dynamic response to the last deglaciation that is large enough to affect interpretation of its mass balance from altimetry. Copyright © 2016, American Association for the Advancement of Science.

Greenland ice sheet is changing

NASA Image and Video Library

2015-08-27

At 1 p.m. EDT (10 a.m. PDT) on Friday, Aug. 28, NASA's Goddard Space Flight Center in Greenbelt, Maryland, will host a live TV program about agency research into how and why the massive Greenland ice sheet is changing. The event features scientists actively conducting field work in Greenland, along with extensive video footage of their work performed over this summer. Panelists include: Tom Wagner (cryosphere program scientist with NASA's Earth Science Division), Laurence Smith (chair of the University of California, Los Angeles Department of Geography), Mike Bevis (professor of geodynamics at Ohio State University in Columbus), Sophie Nowicki (physical scientist at Goddard), and Josh Willis (JPL). The Friday program will air live on NASA TV and stream online at: www.nasa.gov/nasatv. To ask questions via social media during the televised event, use the hashtag #askNASA. NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Publications - GMC 395 | Alaska Division of Geological & Geophysical

Science.gov Websites

investigations of the diatom stratigraphy of Borehole TA8, Portage Alaska: Alaska Division of Geological & Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical DGGS GMC 395 Publication Details Title: Preliminary investigations of the diatom stratigraphy of

76 FR 45217 - Fisheries of the Exclusive Economic Zone Off Alaska; Central Gulf of Alaska Rockfish Program...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-28

..., management, safety, and economic gains realized under the Rockfish Pilot Program and viability of the Gulf of...-BA97 Fisheries of the Exclusive Economic Zone Off Alaska; Central Gulf of Alaska Rockfish Program... available for public review and comment. The groundfish fisheries in the exclusive economic zone of Alaska...

Alaska Department of Labor and Workforce Development

Science.gov Websites

Market Information Alaska Job Centers Hot Topics Get Paid to Learn a Trade! Apprenticeship Alaska Career USAJOBS - Federal Gov. Jobs Apprenticeship Alaska Career Information System Veterans' Services Youth

Tourism in rural Alaska

Treesearch

Katrina Church-Chmielowski

2007-01-01

Tourism in rural Alaska is an education curriculum with worldwide relevance. Students have started small businesses, obtained employment in the tourism industry and gotten in touch with their people. The Developing Alaska Rural Tourism collaborative project has resulted in student scholarships, workshops on website development, marketing, small...

76 FR 270 - Alaska: Adequacy of Alaska Municipal Solid Waste Landfill Permit Program

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-04

...] Alaska: Adequacy of Alaska Municipal Solid Waste Landfill Permit Program AGENCY: Environmental Protection... approved Municipal Solid Waste Landfill (MSWLF) permit program. The approved modification allows the State..., EPA issued a final rule (69 FR 13242) amending the Municipal Solid Waste Landfill (MSWLF) criteria in...

Physical activity patterns in Greenland: a country in transition.

PubMed

Dahl-Petersen, Inger K; Jørgensen, Marit E; Bjerregaard, Peter

2011-11-01

To examine differences in physical activity patterns among Inuit in Greenland in relation to social transition. The Inuit in Greenland are an indigenous population in the circumpolar north who are experiencing rapid social transition. Physical activity patterns were assessed by the International Physical Activity Questionnaire (long version). The population was divided into six groups according to different stages of social change, measured on the basis of education, current residence and occupation. Data were collected in a country-wide cross-sectional population survey among adult Inuit in Greenland from 2005 to 2009. Men with long vocational or academic education living in towns (latest stage of social change) spent significantly less time on occupational physical activity (p = 0.001) compared with hunters and fishermen in villages (earliest stage of social change) (trend test p = 0.01). Women in the latest stage of change spent significantly less time on domestic physical activity (p < 0.001) (trend test p = 0.06) compared with women in the earliest stage of social change. This was also found for physical activity during transportation (p = 0.02 and p = 0.01 for men and women, respectively). No significant difference was found for leisure time physical activity. Men and women in the latest stage of social change spent more time on sedentary activity (p < 0.001). Differences in physical activity patterns among Inuit in Greenland included decreasing time spent on domestic and occupational physical activity and increasing time spent on sedentary activities along with social change. Knowledge of changes in physical activity patterns in relation to social transition is important in prevention of obesity, type 2 diabetes and lifestyle diseases.

Seasonal Subglacial Hydrological Evolution of a Greenland Tidewater Glacier

NASA Astrophysics Data System (ADS)

Schild, K. M.; Hawley, R. L.; Morriss, B. F.; Hoffman, M. J.; Catania, G. A.; Neumann, T.

2012-12-01

The contribution to sea level rise from melting ice sheets has doubled in the last decade. The rapid acceleration of Greenland's outlet glaciers has been one of the dominant factors in this contribution. Also in this last decade, Greenland has experienced an increase in average summer atmospheric temperature and associated increases in summer surface melt duration and extent. These increases in surface melt have been strongly linked with increased glacier sliding at the base through changes in the sublgacial hydrological system. Previous research has looked at conduit evolution of land-terminating and alpine glaciers, but marine-terminating glaciers, although more sensitive to environmental change, have not been thoroughly studied. The goal of this project is to investigate the timing between rapid supra-glacial lake drainages (delivering a pulse of water to the base) and the appearance of a meltwater sediment plume at the terminus. We constructed a high-temporal resolution (sub-daily) time series of lake evolution, drainage and sediment plume appearance at Rink Isbræ (west Greenland) using MODIS satellite imagery from 2000-2012. We compare the time of year and the rate of travel of the pulse to establish a better understanding of seasonal conduit development for tidewater outlet glaciers. Additionally, in comparing these variables between years, we plan to examine how the subglacial system changes when melt season duration and intensity increase. With a clearer understanding of the mechanisms controlling fluctuations in ice flow, specifically those acting in the subglacial environment, scientists can more accurately predict the future of the Greenland Ice Sheet and its effect on global sea level rise.

Factors Controlling Methane in Arctic Lakes of Southwest Greenland

PubMed Central

2016-01-01

We surveyed 15 lakes during the growing season of 2014 in Arctic lakes of southwest Greenland to determine which factors influence methane concentrations in these systems. Methane averaged 2.5 μmol L-1 in lakes, but varied a great deal across the landscape with lakes on older landscapes farther from the ice sheet margin having some of the highest values of methane reported in lakes in the northern hemisphere (125 μmol L-1). The most important factors influencing methane in Greenland lakes included ionic composition (SO4, Na, Cl) and chlorophyll a in the water column. DOC concentrations were also related to methane, but the short length of the study likely underestimated the influence and timing of DOC on methane concentrations in the region. Atmospheric methane concentrations are increasing globally, with freshwater ecosystems in northern latitudes continuing to serve as potentially large sources in the future. Much less is known about how freshwater lakes in Greenland fit in the global methane budget compared to other, more well-studied areas of the Arctic, hence our work provides essential data for a more complete view of this rapidly changing region. PMID:27454863

Factors Controlling Methane in Arctic Lakes of Southwest Greenland.

PubMed

Northington, Robert M; Saros, Jasmine E

2016-01-01

We surveyed 15 lakes during the growing season of 2014 in Arctic lakes of southwest Greenland to determine which factors influence methane concentrations in these systems. Methane averaged 2.5 μmol L-1 in lakes, but varied a great deal across the landscape with lakes on older landscapes farther from the ice sheet margin having some of the highest values of methane reported in lakes in the northern hemisphere (125 μmol L-1). The most important factors influencing methane in Greenland lakes included ionic composition (SO4, Na, Cl) and chlorophyll a in the water column. DOC concentrations were also related to methane, but the short length of the study likely underestimated the influence and timing of DOC on methane concentrations in the region. Atmospheric methane concentrations are increasing globally, with freshwater ecosystems in northern latitudes continuing to serve as potentially large sources in the future. Much less is known about how freshwater lakes in Greenland fit in the global methane budget compared to other, more well-studied areas of the Arctic, hence our work provides essential data for a more complete view of this rapidly changing region.

Large Fluctuations in Speed on Jakobshavn Isbrae, Greenland

NASA Technical Reports Server (NTRS)

Joughin, Ian; Abdalati, Waleed; Fahnestock, Mark

2003-01-01

We have assembled an 18-year velocity record for Jakobshavn Isbrae, Greenland. From a 1985 speed of approx. 7000 m/yr, the glacier had slowed by approx. 1000 m/ yr in 1992, which coincided with independently observed thickening in the early 1990s . The glacier then sped up by approx. 4000 m/yr between 1997 and 2000, during which time other measurements show rapid thinning . From 2000 to 2003, the glacier s floating ice tongue almost entirely disintegrated, as speed increased to 12,600 m/yr. If the retreat of the ice tongue caused the acceleration, then similar losses of floating ice tongues since the Little Ice Age may explain the current rapid thinning observed for many of Greenland s outlet glaciers.

Presentations - Twelker, Evan and Lande, Lauren, 2015 | Alaska Division of

Science.gov Websites

Geological & Geophysical Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of (AVO) Mineral Resources Alaska's Mineral Industry Reports AKGeology.info Rare Earth Elements WebGeochem

A 70-year record of outlet glacier retreat in northern Greenland

NASA Astrophysics Data System (ADS)

Hill, Emily; Carr, Rachel; Stokes, Chris; Gudmundsson, Hilmar

2017-04-01

Over the past two decades, the Greenland Ice Sheet (GrIS) has undergone accelerated mass loss increasing its contribution to sea level rise. This is partly attributed to increased mass loss from dynamic marine-terminating outlet glaciers. Despite marine-terminating outlet glaciers in northern Greenland draining 40% of the ice sheet by area, they are comparatively less well-studied than other regions of the ice sheet (e.g. central west or south-east). This region could be susceptible to marine-ice sheet instability due to large proportions of the bedrock rested below sea level and is also unique in the presence of large floating ice tongues. Here, we use a range of satellite imagery sources, accompanied by historical maps, to examine multi-decadal front position changes at 21 outlet glaciers in northern Greenland between 1948 and 2016. We accompany these terminus changes, with annual records of ice velocity, climate-ocean forcing data, and glacier-specific factors (e.g. fjord-width and basal topography) to understand the dominant forcing on glacier dynamics in the region. Over the last 70 years, there has been a clear pattern of glacier retreat in northern Greenland. This is particularly notable during the last two decades, where 62% of our study glaciers showed accelerated retreat. This was most notable at Humboldt, Tracy, Hagen Brae, C. H. Ostenfeld and Petermann Glaciers, and in the case of the latter three glaciers, this involved substantial retreat of their floating ice tongues (> 10 km). Alongside retreat, several study glaciers underwent simultaneous velocity increases. However, the collapse of floating ice tongues did not always result in increased velocity. Similar to other regions of the ice sheet, recent glacier retreat in the northern regions of the Greenland Ice Sheet could be linked to climatic-oceanic forcing, but at this stage this remains largely unknown. This response to external forcing is further complicated by the presence of glacier

Raised BMI cut-off for overweight in Greenland Inuit – a review

PubMed Central

Andersen, Stig; Fleischer Rex, Karsten; Noahsen, Paneeraq; Sørensen, Hans Christian Florian; Mulvad, Gert; Laurberg, Peter

2013-01-01

Background Obesity is associated with increased morbidity and premature death. Obesity rates have increased worldwide and the WHO recommends monitoring. A steep rise in body mass index (BMI), a measure of adiposity, was detected in Greenland from 1963 to 1998. Interestingly, the BMI starting point was in the overweight range. This is not conceivable in a disease-free, physically active, pre-western hunter population. Objective This led us to reconsider the cut-off point for overweight among Inuit in Greenland. Design and findings We found 3 different approaches to defining the cut-off point of high BMI in Inuit. First, the contribution to the height by the torso compared to the legs is relatively high. This causes relatively more kilograms per centimetre of height that increases the BMI by approximately 10% compared to Caucasian whites. Second, defining the cut-off by the upper 90-percentile of BMI from height and weight in healthy young Inuit surveyed in 1963 estimated the cut-off point to be around 10% higher compared to Caucasians. Third, if similar LDL-cholesterol and triglycerides are assumed for a certain BMI in Caucasians, the corresponding BMI in Inuit in both Greenland and Canada is around 10% higher. However, genetic admixture of Greenland Inuit and Caucasian Danes will influence this difference and hamper a clear distinction with time. Conclusion Defining overweight according to the WHO cut-off of a BMI above 25 kg/m2 in Greenland Inuit may overestimate the number of individuals with elevated BMI. PMID:23986904

76 FR 303 - Alaska: Adequacy of Alaska's Municipal Solid Waste Landfill Permit Program

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-04

...] Alaska: Adequacy of Alaska's Municipal Solid Waste Landfill Permit Program AGENCY: Environmental... modification of its approved Municipal Solid Waste Landfill (MSWLF) permit program. On March 22, 2004, EPA..., Waste, and Toxics, U.S. EPA, Region 10, 1200 Sixth Avenue, Suite 900, Mailstop: AWT-122, Seattle, WA...

Greenland Ice Sheet Monitoring Network (GLISN): Contributions to Science and Society

NASA Astrophysics Data System (ADS)

Anderson, K. R.; Bonaime, S.; Clinton, J. F.; Dahl-Jensen, T.; Debski, W. M.; Giardini, D.; Govoni, A.; Kanao, M.; Larsen, T. B.; Lasocki, S.; Lee, W. S.; McCormack, D. A.; Mykkeltveit, S.; Nettles, M.; Stutzmann, E.; Strollo, A.; Sweet, J. R.; Tsuboi, S.; Vallee, M.

2017-12-01

The Greenland Ice Sheet Monitoring Network (GLISN) is a broadband, multi-use seismological network, enhanced by selected geodetic observations, designed with the capability to allow researchers to understand the changes currently occurring in the Arctic, and with the operational characteristics necessary to enable response to those changes as understanding improves. GLISN was established through an international collaboration, with 10 nations coordinating their efforts to develop the current 34-station observing network during the last eight years. All of the data collected are freely and openly available in near-real time. The network was designed to transform the community capability for recording, analysis, and interpretation of seismic signals generated by discrete events in Greenland and the Arctic, as well as those traversing the region. Data from the network support a wide range of uses, including estimation of the properties of the solid Earth that control isostatic adjustment rates and set key boundary conditions for ice-sheet evolution; analysis of tectonic earthquakes throughout Greenland and the Arctic; study of the seismic signals associated with large calving events and changing glacier dynamics; and variations in ice and snow properties within the Greenland Ice Sheet. Recordings from the network have also provided invaluable data for rapid evaluation and understanding of the devastating landslide and tsunami that occurred near Nuugaatsiaq, Greenland, in June, 2017. The GLISN strategy of maximizing data quality from a network of approximately evenly distributed stations, delivering data in near-real time, and archiving a continuous data stream easily accessible to researchers, allows continuous discovery of new uses while also facilitating the generation of data products, such as catalogs of tectonic and glacial earthquakes and GPS-based estimates of snow height, that allow for assessment of change over time.

Publications - Geospatial Data | Alaska Division of Geological &

Science.gov Websites

from rocks collected in the Richardson mining district, Big Delta Quadrangle, Alaska: Alaska Division , 40Ar/39Ar data, Alaska Highway corridor from Delta Junction to Canada border, parts of Mount Hayes

Gonorrhoea in Greenland, incidence and previous preventive measures: a review to improve future strategies

PubMed Central

Berntsen, Sine; Karlsen, Anders Peder Højer; Pedersen, Michael Lynge; Mulvad, Gert

2017-01-01

ABSTRACT Gonorrhoea continues to be a significant health challenge in Greenland. The aim of this study was to describe the development of gonorrhoea in Greenland through time including incidence rates and previous measures taken to address the challenge. A systematic literature search in PubMed, Embase and The Cochrane Library was conducted. Furthermore, local archives were searched in the Health Clinic in Nuuk for relevant literature. From the 1940s the incidence of gonorrhoea increased steadily with a steep incline around 1970, possibly as a consequence of changes in living conditions and urbanisation. Significant declines in the incidence were seen the late 1970s and again in the late 1980s, most likely in the wake of an outbreak of ulcus molle/chancroid in the 1970s and as a result of focused education in venereology for Greenlandic nurses in the late 1980s combined with the stop-AIDS campaign. Since the early 1990s the incidence of gonorrhoea in Greenland has not risen to previously high levels. However, the incidence remains high and with a gradually increasing trend. Prevention intervention strategies such as peer-to-peer sexual education, storytelling and involvement of parent/guardian in sexual education of the youth could be appropriate approaches to improve sexual health in Greenland. PMID:28745556

Gonorrhoea in Greenland, incidence and previous preventive measures: a review to improve future strategies.

PubMed

Berntsen, Sine; Karlsen, Anders Peder Højer; Pedersen, Michael Lynge; Mulvad, Gert

2017-01-01

Gonorrhoea continues to be a significant health challenge in Greenland. The aim of this study was to describe the development of gonorrhoea in Greenland through time including incidence rates and previous measures taken to address the challenge. A systematic literature search in PubMed, Embase and The Cochrane Library was conducted. Furthermore, local archives were searched in the Health Clinic in Nuuk for relevant literature. From the 1940s the incidence of gonorrhoea increased steadily with a steep incline around 1970, possibly as a consequence of changes in living conditions and urbanisation. Significant declines in the incidence were seen the late 1970s and again in the late 1980s, most likely in the wake of an outbreak of ulcus molle/chancroid in the 1970s and as a result of focused education in venereology for Greenlandic nurses in the late 1980s combined with the stop-AIDS campaign. Since the early 1990s the incidence of gonorrhoea in Greenland has not risen to previously high levels. However, the incidence remains high and with a gradually increasing trend. Prevention intervention strategies such as peer-to-peer sexual education, storytelling and involvement of parent/guardian in sexual education of the youth could be appropriate approaches to improve sexual health in Greenland.

Publications - DDS 7 | Alaska Division of Geological & Geophysical Surveys

Science.gov Websites

Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in Alaska DGGS DDS 7 Publication Details Title: Alaska Coastal Profile Tool (ACPT) Authors: DGGS Staff ): Alaska Statewide Bibliographic Reference DGGS Staff, 2014, Alaska Coastal Profile Tool (ACPT): Alaska

Harvesting morels after wildfire in Alaska.

Treesearch

Tricia L. Wurtz; Amy L. Wiita; Nancy S. Weber; David Pilz

2005-01-01

Morels are edible, choice wild mushrooms that sometimes fruit prolifically in the years immediately after an area has been burned by wildfire. Wildfires are common in interior Alaska; an average of 708,700 acres burned each year in interior Alaska between 1961 and 2000, and in major fire years, over 2 million acres burned. We discuss Alaska's boreal forest...

The State of Alaska Agency Directory

Science.gov Websites

State Government Jobs Federal Jobs Starting a Small Business Living Get a Driver License Get a Hunting /Fishing License Get a Birth Certificate, Marriage License, etc. Alaska Permanent Fund Dividend Statewide Highway Conditions Take a University Class Look up Alaska Laws Recreation Find a Recreational Area Alaska

Publications - AR 2006 | Alaska Division of Geological & Geophysical

Science.gov Websites

Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications AR 2006 main content DGGS AR 2006 Publication Details Title: Alaska Division of Geological & Geophysical Surveys Annual

Publications - AR 2000 | Alaska Division of Geological & Geophysical

Science.gov Websites

Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications AR 2000 main content DGGS AR 2000 Publication Details Title: Alaska Division of Geological & Geophysical Surveys Annual

Publications - AR 2003 | Alaska Division of Geological & Geophysical

Science.gov Websites

Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications AR 2003 main content DGGS AR 2003 Publication Details Title: Alaska Division of Geological & Geophysical Surveys Annual

Publications - AR 2004 | Alaska Division of Geological & Geophysical

Science.gov Websites

Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Facebook DGGS News Natural Resources Geological & Geophysical Surveys Publications AR 2004 main content DGGS AR 2004 Publication Details Title: Alaska Division of Geological & Geophysical Surveys Annual

Using Vertically Integrated Ocean Fields to Characterize Greenland Icebergs' Distribution and Lifetime

NASA Astrophysics Data System (ADS)

Marson, Juliana M.; Myers, Paul G.; Hu, Xianmin; Le Sommer, Julien

2018-05-01

Icebergs represent approximately half of Greenland's yearly mass loss, having important implications for biological productivity, freshwater fluxes in the ocean, and navigation. This study applies an iceberg model that uses integrated ocean fields (from surface to iceberg keel) to simulate the drift and decay of Greenland icebergs. This version of iceberg model (VERT) is compared with a more widely adopted version (SURF) which only uses surface ocean fields in its equations. We show that icebergs in VERT tend to drift along the shelf break, while in SURF they concentrate along the coastline. Additionally, we show that Greenland's southeast coast is the source of ˜60% of the icebergs that cross the interior of the Labrador Sea—a region that stages buoyancy-driven convection and is, therefore, sensitive to freshwater input.

Alaska Community Forest Council

Science.gov Websites

Conservation Education Timber Management Wildland Fire & Aviation Burn Permits Firewise Alaska Brochure (PDF) Fire Management Plans Fire Assignments Annual Fire Statistics Fire Terms Glossary Incident Business Management Grants Become an Alaska Firewise Community Community Wildland Fire Protection Plans

ALASKA MARINE VHF VOICE

Science.gov Websites

Tsunamis 406 EPIRB's National Weather Service Marine Forecasts ALASKA MARINE VHF VOICE Marine Forecast greater danger near shore or any shallow waters? NATIONAL WEATHER SERVICE PRODUCTS VIA ALASKA MARINE VHF VOICE NOAA broadcasts offshore forecasts, nearshore forecasts and storm warnings on marine VHF channels

Younger Dryas cooling and the Greenland climate response to CO2.

PubMed

Liu, Zhengyu; Carlson, Anders E; He, Feng; Brady, Esther C; Otto-Bliesner, Bette L; Briegleb, Bruce P; Wehrenberg, Mark; Clark, Peter U; Wu, Shu; Cheng, Jun; Zhang, Jiaxu; Noone, David; Zhu, Jiang

2012-07-10

Greenland ice-core δ(18)O-temperature reconstructions suggest a dramatic cooling during the Younger Dryas (YD; 12.9-11.7 ka), with temperatures being as cold as the earlier Oldest Dryas (OD; 18.0-14.6 ka) despite an approximately 50 ppm rise in atmospheric CO(2). Such YD cooling implies a muted Greenland climate response to atmospheric CO(2), contrary to physical predictions of an enhanced high-latitude response to future increases in CO(2). Here we show that North Atlantic sea surface temperature reconstructions as well as transient climate model simulations suggest that the YD over Greenland should be substantially warmer than the OD by approximately 5 °C in response to increased atmospheric CO(2). Additional experiments with an isotope-enabled model suggest that the apparent YD temperature reconstruction derived from the ice-core δ(18)O record is likely an artifact of an altered temperature-δ(18)O relationship due to changing deglacial atmospheric circulation. Our results thus suggest that Greenland climate was warmer during the YD relative to the OD in response to rising atmospheric CO(2), consistent with sea surface temperature reconstructions and physical predictions, and has a sensitivity approximately twice that found in climate models for current climate due to an enhanced albedo feedback during the last deglaciation.

Hyperspectral surveying for mineral resources in Alaska

USGS Publications Warehouse

Kokaly, Raymond F.; Graham, Garth E.; Hoefen, Todd M.; Kelley, Karen D.; Johnson, Michaela R.; Hubbard, Bernard E.

2016-07-07

Alaska is a major producer of base and precious metals and has a high potential for additional undiscovered mineral resources. However, discovery is hindered by Alaska’s vast size, remoteness, and rugged terrain. New methods are needed to overcome these obstacles in order to fully evaluate Alaska’s geology and mineral resource potential. Hyperspectral surveying is one method that can be used to rapidly acquire data about the distributions of surficial materials, including different types of bedrock and ground cover. In 2014, the U.S. Geological Survey began the Alaska Hyperspectral Project to assess the applicability of this method in Alaska. The primary study area is a remote part of the eastern Alaska Range where porphyry deposits are exposed. In collaboration with the Alaska Division of Geological and Geophysical Surveys, the University of Alaska Fairbanks, and the National Park Service, the U.S. Geological Survey is collecting and analyzing hyperspectral data with the goals of enhancing geologic mapping and developing methods to identify and characterize mineral deposits elsewhere in Alaska.

Greenland Ice Sheet flow response to runoff variability

NASA Astrophysics Data System (ADS)

Stevens, Laura A.; Behn, Mark D.; Das, Sarah B.; Joughin, Ian; Noël, Brice P. Y.; Broeke, Michiel R.; Herring, Thomas

2016-11-01

We use observations of ice sheet surface motion from a Global Positioning System network operating from 2006 to 2014 around North Lake in west Greenland to investigate the dynamical response of the Greenland Ice Sheet's ablation area to interannual variability in surface melting. We find no statistically significant relationship between runoff season characteristics and ice flow velocities within a given year or season. Over the 7 year time series, annual velocities at North Lake decrease at an average rate of -0.9 ± 1.1 m yr-2, consistent with the negative trend in annual velocities observed in neighboring regions over recent decades. We find that net runoff integrated over several preceding years has a negative correlation with annual velocities, similar to findings from the two other available decadal records of ice velocity in western Greenland. However, we argue that this correlation is not necessarily evidence for a direct hydrologic mechanism acting on the timescale of multiple years but could be a statistical construct. Finally, we stress that neither the decadal slowdown trend nor the negative correlation between velocity and integrated runoff is predicted by current ice-sheet models, underscoring that these models do not yet capture all the relevant feedbacks between runoff and ice dynamics needed to predict long-term trends in ice sheet flow.

Vulnerability of Southeast Greenland Glaciers to Warm Atlantic Water From Operation IceBridge and Ocean Melting Greenland Data

NASA Astrophysics Data System (ADS)

Millan, R.; Rignot, E.; Mouginot, J.; Wood, M.; Bjørk, A. A.; Morlighem, M.

2018-03-01

We employ National Aeronautics and Space Administration (NASA)'s Operation IceBridge high-resolution airborne gravity from 2016, NASA's Ocean Melting Greenland bathymetry from 2015, ice thickness from Operation IceBridge from 2010 to 2015, and BedMachine v3 to analyze 20 major southeast Greenland glaciers. The results reveal glacial fjords several hundreds of meters deeper than previously thought; the full extent of the marine-based portions of the glaciers; deep troughs enabling warm, salty Atlantic Water (AW) to reach the glacier fronts and melt them from below; and few shallow sills that limit the access of AW. The new oceanographic and topographic data help to fully resolve the complex pattern of historical ice front positions from the 1930s to 2017: glaciers exposed to AW and resting on retrograde beds have retreated rapidly, while glaciers perched on shallow sills or standing in colder waters or with major sills in the fjords have remained stable.

Project report: Alaska Iways architecture

DOT National Transportation Integrated Search

2005-01-01

The Alaska Department of Transportation and Public Facilities (ADOT&PF) is continually looking at ways to improve the efficiency, safety, and reliability of Alaskas transportation system. This effort includes the application of advanced communicat...

Zooplankton data: Vertical distributions of zooplankton in the Norweigian and Greenland Seas during summer, 1989

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lane, P.V.Z.; Smith, S.L.; Schwarting, E.M.

1993-08-01

Recent studies of zooplankton populations in the Greenland Sea have focused on processes at the Marginal Ice Zone (MIZ) and the areas immediately adjacent to it under the ice and in open water. These studies have shown a relatively short period of intense secondary productivity which is closely linked temporally and spatially to phytoplankton blooms occurring near the ice edge in spring and early summer. During the summer of 1989 we participated in a project focusing on benthic and water column processes in the basins of the Norwegian and Greenland Seas. This study allowed us to compare biological processes atmore » the MIZ with those occurring in the open waters of the Greenland Sea, and to compare processes at both of these locations with those in the Norwegian Sea. The data presented in this report are the results of zooplankton net tows covering the upper 1000 meters of the water column over the Norwegian Sea basin and the Greenland Sea basin, and the upper 500 meters of open water adjacent to the MIZ in the Greenland Sea. Sampling was conducted between 12 and 29 July 1989.« less

Acceleration of Humboldt glacier, north Greenland

NASA Astrophysics Data System (ADS)

Jeong, S.; Howat, I.; Noh, M. J.; King, M. D.

2017-12-01

Here we report on recent abrupt acceleration on the flow speed of Humboldt Glacier (HG) in northern Greenland. The mean annual discharge of this glacier in 2000 was estimated as 8.4Gt/a, placing it among the largest outlet glacier draining the northern coast (Enderlin et al., 2014). Using a combination of remote sensing datasets, we find that following a slight slowing before 2010, HG suddenly sped up by a factor of three between 2012 and 2013, maintaining that increased speed through 2016. Speedup was accompanied by up to 10 m of thinning near the terminus and followed slower, longer-term thinning and retreat. Here we assess possible causes for the speedup, potential for continued acceleration and implication to ice sheet mass balance. ReferenceEnderlin, E. M., I. M. Howat, S. Jeong, M.-J. Noh, J. H. van Angelen, and M. R. van den Broeke (2014), An improved mass budget for the Greenland ice sheet, Geophys. Res. Lett., 41, 866-872, doi:10.1002/2013GL059010.

Holocene thinning of the Greenland ice sheet.

PubMed

Vinther, B M; Buchardt, S L; Clausen, H B; Dahl-Jensen, D; Johnsen, S J; Fisher, D A; Koerner, R M; Raynaud, D; Lipenkov, V; Andersen, K K; Blunier, T; Rasmussen, S O; Steffensen, J P; Svensson, A M

2009-09-17

On entering an era of global warming, the stability of the Greenland ice sheet (GIS) is an important concern, especially in the light of new evidence of rapidly changing flow and melt conditions at the GIS margins. Studying the response of the GIS to past climatic change may help to advance our understanding of GIS dynamics. The previous interpretation of evidence from stable isotopes (delta(18)O) in water from GIS ice cores was that Holocene climate variability on the GIS differed spatially and that a consistent Holocene climate optimum-the unusually warm period from about 9,000 to 6,000 years ago found in many northern-latitude palaeoclimate records-did not exist. Here we extract both the Greenland Holocene temperature history and the evolution of GIS surface elevation at four GIS locations. We achieve this by comparing delta(18)O from GIS ice cores with delta(18)O from ice cores from small marginal icecaps. Contrary to the earlier interpretation of delta(18)O evidence from ice cores, our new temperature history reveals a pronounced Holocene climatic optimum in Greenland coinciding with maximum thinning near the GIS margins. Our delta(18)O-based results are corroborated by the air content of ice cores, a proxy for surface elevation. State-of-the-art ice sheet models are generally found to be underestimating the extent and changes in GIS elevation and area; our findings may help to improve the ability of models to reproduce the GIS response to Holocene climate.

Level and temporal trend of perfluoroalkyl acids in Greenlandic Inuit.

PubMed

Long, Manhai; Bossi, Rossana; Bonefeld-Jørgensen, Eva C

2012-03-19

Perfluoroalkyl acids (PFAAs) have been detected in human blood, breast milk and umbilical cord blood across the globe. PFAAs do accumulate in the marine food chain in Arctic regions. In Greenland, increasing PFAA concentrations were observed during 1982-2006 in ringed seals and polar bears. However, until now, no data have been reported for PFAAs in Greenlandic Inuit. This study assesses the level and temporal trend of serum PFAAs in Greenlandic Inuit. Cross-section and temporal time trend survey. Serum PFAA levels were determined in 284 Inuit from different Greenlandic districts using liquid chromatography-tandem mass spectrometry with electrospray ionization. The temporal time trend of serum PFAAs in Nuuk Inuit during 1998-2005 and the correlation between serum PFAAs and legacy persistent organic pollutants (POPs) were explored. Serum PFAA levels were higher in Nuuk Inuit than in non-Nuuk Inuit. Within the same district, higher PFAA levels were observed for males. An age-dependent, increasing trend of serum PFAA levels in the period from 1998-2005 was observed for Nuuk Inuit. For the pooled gender data, no significant association between PFAAs and legacy POPs was observed for Nuuk Inuit while for non-Nuuk Inuit this correlation was significant. No correlation between PFAAs and legacy POPs was found for male Inuit, whereas significant correlation was observed both for pooled female Inuit and for non-Nuuk Inuit females. We suggest that sources other than seafood intake might contribute to the observed higher PFAA levels in Nuuk Inuit compared to the pooled non-Nuuk Inuit.

25 CFR 243.12 - Are Alaska reindeer trust assets maintained by the U.S. Government for the benefit of Alaska...

Code of Federal Regulations, 2010 CFR

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false Are Alaska reindeer trust assets maintained by the U.S. Government for the benefit of Alaska Natives? 243.12 Section 243.12 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE REINDEER IN ALASKA § 243.12 Are Alaska reindeer trust assets maintained by the U.S. Government for the...

Publications - GMC 222 | Alaska Division of Geological & Geophysical

Science.gov Websites

and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a BP Exploration (Alaska) Inc. Malguk #1 well Authors: Unknown Publication Date: 1994 Publisher: Alaska reflectance data from cuttings (440-11,375') of the BP Exploration (Alaska) Inc. Malguk #1 well: Alaska

Law Library - Alaska Court System

Science.gov Websites

, Federal Info, US Supreme Court, State Links, 9th Circuit Links Library Databases & eBooks WestlawNext state agencies Alaska Supreme Court briefs (1960-current) Alaska Court of Appeals briefs (1980-current

Volcanic activity in Alaska: summary of events and response of the Alaska Volcano Observatory 1993

USGS Publications Warehouse

Neal, Christina A.; McGimsey, Robert G.; Doukas, Michael P.

1996-01-01

During 1993, the Alaska Volcano Observatory (AVO) responded to episodes of eruptive activity or false alarms at nine volcanic centers in the state of Alaska. Additionally, as part of a formal role in KVERT (the Kamchatkan Volcano Eruption Response Team), AVO staff also responded to eruptions on the Kamchatka Peninsula, details of which are summarized in Miller and Kurianov (1993). In 1993, AVO maintained seismic instrumentation networks on four volcanoes of the Cook Inlet region--Spurr, Redoubt, Iliamna, and Augustine--and two stations at Dutton Volcano near King Cove on the Alaska Peninsula. Other routine elements of AVO's volcano monitoring program in Alaska include periodic airborne measurement of volcanic SO2 and CO2 at Cook Inlet volcanoes (Doukas, 1995) and maintenance of a lightning detection system in Cook Inlet (Paskievitch and others, 1995).

Publications - NL 2002-1 | Alaska Division of Geological & Geophysical

Science.gov Websites

Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical 2002 Publisher: Alaska Division of Geological & Geophysical Surveys Ordering Info: Download below Reference DGGS Staff, and Werdon, M.B., 2002, Alaska GeoSurvey News - Geologic Investigations in the Salcha

Geologic Map of Central (Interior) Alaska

USGS Publications Warehouse

Wilson, Frederic H.; Dover, James H.; Bradley, Dwight C.; Weber, Florence R.; Bundtzen, Thomas K.; Haeussler, Peter J.

1998-01-01

Introduction: This map and associated digital databases are the result of a compilation and reinterpretation of published and unpublished 1:250,000- and limited 1:125,000- and 1:63,360-scale mapping. The map area covers approximately 416,000 sq km (134,000 sq mi) and encompasses 25 1:250,000-scale quadrangles in central Alaska. The compilation was done as part of the U.S. Geological Survey National Surveys and Analysis project, whose goal is nationwide assemble geologic, geochemical, geophysical, and other data. This map is an early product of an effort that will eventually encompass all of Alaska, and is the result of an agreement with the Alaska Department of Natural Resources, Division of Oil And Gas, to provide data on interior basins in Alaska. A paper version of the three map sheets has been published as USGS Open-File Report 98-133. Two geophysical maps that cover the identical area have been published earlier: 'Bouguer gravity map of Interior Alaska' (Meyer and others, 1996); and 'Merged aeromagnetic map of Interior Alaska' (Meyer and Saltus, 1995). These two publications are supplied in the 'geophys' directory of this report.

Publications - GMC 167 | Alaska Division of Geological & Geophysical

Science.gov Websites

and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a Arco Alaska W. Mikkelsen Unit #2 well Authors: Pawlewicz, Mark Publication Date: 1990 Publisher: Alaska , Vitrinite reflectance data of cuttings (6160'-11030') from the Arco Alaska W. Mikkelsen Unit #2 well: Alaska

Publications - GMC 257 | Alaska Division of Geological & Geophysical

Science.gov Websites

and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a ARCO Alaska Inc. Colville River #1 well Authors: Unknown Publication Date: 1995 Publisher: Alaska reflectance data from cuttings (1,470-7,300') of the ARCO Alaska Inc. Colville River #1 well: Alaska Division

Publications - GMC 258 | Alaska Division of Geological & Geophysical

Science.gov Websites

and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a ARCO Alaska Inc. Kuukpik #3 well Authors: Unknown Publication Date: 1995 Publisher: Alaska Division of from cuttings (3,220-6,570') of the ARCO Alaska Inc. Kuukpik #3 well: Alaska Division of Geological

Operation of a Radar Altimeter over the Greenland Ice Sheet

NASA Technical Reports Server (NTRS)

Grund, Matthew D.

1996-01-01

This thesis presents documentation for the Advanced Application Flight Experiment (AAFE) pulse compression radar altimeter and its role in the NASA Multisensor Airborne Altimetry Experiment over Greenland in 1993. The AAFE Altimeter is a Ku-band microwave radar which has demonstrated 14 centimeter range precision in operation over arctic ice. Recent repairs and improvements were required to make the Greenland missions possible. Transmitter, receiver and software modifications, as well as the integration of a GPS receiver are thoroughly documented. Procedures for installation, and operation of the radar are described. Finally, suggestions are made for further system improvements.

Adverse metabolic risk profiles in Greenlandic Inuit children compared to Danish children.

PubMed

Munch-Andersen, T; Sorensen, K; Andersen, L B; Aachmann-Andersen, N J; Aksglaede, L; Juul, A; Helge, J W

2013-06-01

During recent decades, the prevalence of metabolic morbidity has increased rapidly in adult Greenlandic Inuit. To what extent this is also reflected in the juvenile Inuit population is unknown. The objective was, therefore, in the comparison with Danish children, to evaluate metabolic profiles in Greenlandic Inuit children from the capital in the southern and from the northern most villages 187 Inuit and 132 Danish children were examined with anthropometrics, pubertal staging, fasting blood samples, and a maximal aerobic test. Both Inuit children living in Nuuk and the northern villages had significantly higher glucose, total cholesterol, apolipoprotein A1 levels, and diastolic blood pressure compared with Danish children after adjustment for differences in adiposity and aerobic fitness levels. The Inuit children living in Nuuk had significantly higher BMI, body fat %, HbA1 c, and significantly lower aerobic fitness and ApoA1 levels than northern living Inuit children. Greenlandic Inuit children had adverse metabolic health profile compared to the Danish children, the differences where more pronounced in Inuit children living in Nuuk. The tendencies toward higher prevalence of diabetes and metabolic morbidity in the adult Greenlandic Inuit population may also be present in the Inuit children population. Copyright © 2013 The Obesity Society.

Surface elevation change on ice caps in the Qaanaaq region, northwestern Greenland

NASA Astrophysics Data System (ADS)

Saito, Jun; Sugiyama, Shin; Tsutaki, Shun; Sawagaki, Takanobu

2016-09-01

A large number of glaciers and ice caps (GICs) are distributed along the Greenland coast, physically separated from the ice sheet. The total area of these GICs accounts for 5% of Greenland's ice cover. Melt water input from the GICs to the ocean substantially contributed to sea-level rise over the last century. Here, we report surface elevation changes of six ice caps near Qaanaaq (77°28‧N, 69°13‧W) in northwestern Greenland based on photogrammetric analysis of stereo pair satellite images. We processed the images with a digital map plotting instrument to generate digital elevation models (DEMs) in 2006 and 2010 with a grid resolution of 500 m. Generated DEMs were compared to measure surface elevation changes between 2006 and 2010. Over the study area of the six ice caps, covering 1215 km2, the mean rate of elevation change was -1.1 ± 0.1 m a-1. This rate is significantly greater than that previously reported for the 2003-2008 period (-0.6 ± 0.1 m a-1) for GICs all of northwestern Greenland. This increased mass loss is consistent with the rise in summer temperatures in this region at a rate of 0.12 °C a-1 for the 1997-2013 period.

Arctic Amplification and the Northward shift of a new Greenland melting record

NASA Astrophysics Data System (ADS)

Tedesco, Marco; Mote, Thomas; Fettweis, Xavier; Hanna, Edward; Booth, James; Jeyaratnam, Jeyavinoth; Datta, Rajashree; Briggs, Kate

2016-04-01

Large-scale atmospheric circulation controls the mass and energy balance of the Greenland ice sheet through its impact on radiative budget, runoff and accumulation. Using reanalysis data and the outputs of a regional climate model, here we show that the persistence of an exceptional atmospheric ridge, centred over the Arctic Ocean was responsible for a northward shift of surface melting records over Greenland, and for increased accumulation in the south during the summer of 2015. Concurrently, new records of mean monthly zonal winds at 500 hPa and of the maximum latitude of ridge peaks of the 5700±50 m isohypse over the Arctic were also set. An unprecedented (1948 - 2015) and sustained jet stream easterly flow promoted enhanced runoff, increased surface temperatures and decreased albedo in northern Greenland, while inhibiting melting in the south. The exceptional 2015 summer Arctic atmospheric conditions are consistent with the anticipated effects of Arctic Amplification, including slower zonal winds and increased jet stream wave amplitude. Properly addressing the impact of Arctic Amplification on surface runoff of the Greenland ice sheet is crucial for rigorously quantifying its contribution to current and future sea level rise, and the relative impact of freshwater discharge on the surrounding ocean.

Publications - DDS 4 | Alaska Division of Geological & Geophysical Surveys

Science.gov Websites

Datasets of Alaska: Alaska Division of Geological & Geophysical Surveys Digital Data Series 4, http ; Alaska Statewide Maps; Alaska, State of; Digital Elevation Model; Digital Surface Model (DSM); Geologic

Late glacial and Holocene history of the Greenland Ice Sheet margin, Nunatarssuaq, Northwestern Greenland

NASA Astrophysics Data System (ADS)

Farnsworth, L. B.; Kelly, M. A.; Axford, Y.; Bromley, G. R.; Osterberg, E. C.; Howley, J. A.; Zimmerman, S. R. H.; Jackson, M. S.; Lasher, G. E.; McFarlin, J. M.

2015-12-01

Defining the late glacial and Holocene fluctuations of the Greenland Ice Sheet (GrIS) margin, particularly during periods that were as warm or warmer than present, provides a longer-term perspective on present ice margin fluctuations and informs how the GrIS may respond to future climate conditions. We focus on mapping and dating past GrIS extents in the Nunatarssuaq region of northwestern Greenland. During the summer of 2014, we conducted geomorphic mapping and collected rock samples for 10Be surface exposure dating as well as subfossil plant samples for 14C dating. We also obtained sediment cores from an ice-proximal lake. Preliminary 10Be ages of boulders deposited during deglaciation of the GrIS subsequent to the Last Glacial Maximum range from ~30-15 ka. The apparently older ages of some samples indicate the presence of 10Be inherited from prior periods of exposure. These ages suggest deglaciation occurred by ~15 ka however further data are needed to test this hypothesis. Subfossil plants exposed at the GrIS margin on shear planes date to ~ 4.6-4.8 cal. ka BP and indicate less extensive ice during middle Holocene time. Additional radiocarbon ages from in situ subfossil plants on a nunatak date to ~3.1 cal. ka BP. Geomorphic mapping of glacial landforms near Nordsø, a large proglacial lake, including grounding lines, moraines, paleo-shorelines, and deltas, indicate the existence of a higher lake level that resulted from a more extensive GrIS margin likely during Holocene time. A fresh drift limit, characterized by unweathered, lichen-free clasts approximately 30-50 m distal to the modern GrIS margin, is estimated to be late Holocene in age. 10Be dating of samples from these geomorphic features is in progress. Radiocarbon ages of subfossil plants exposed by recent retreat of the GrIS margin suggest that the GrIS was at or behind its present location at AD ~1650-1800 and ~1816-1889. Results thus far indicate that the GrIS margin in northwestern Greenland

Precursory Seismicity Associated With Landslides, Including the 2017 Tsunamigenic Landslide in the Karrat Fjord, Greenland

NASA Astrophysics Data System (ADS)

Caplan-Auerbach, J.

2017-12-01

On the evening of June 17 2017, a massive landslide fell from the wall of the Karrat Fjord, Greenland, generating a tsunami that caused the deaths of four residents in the nearby village of Nuugaatsiaq. The slide took place at a bluff 30 km from the village, where a broadband seismometer (DK.NUUG) is permanently deployed. The landslide generated a seismic signal initially interpreted as a magnitude 4.1 earthquake, as well as a tsunami that initially reached heights exceeding 100 m. Prior to the large seismic signal, however, station NUUG detected a series of several dozen small pulses, most of which were highly similar in time series. The pulses occur more frequently with time, until they effectively merge with the seismic signal of the landslide. The pulses were not detected on any other seismic stations, so their source locations cannot be calculated, but particle motions suggest that they were coming from an azimuth of 30o, consistent with the location of the landslide relative to Nuugaatsiaq. This particular sequence, in which small, repeating earthquakes occur with increasing frequency prior to a landslide, has been observed in at least four other locations: (1) on Mt. Baker (Washington) during an ice avalanche in 1976 (Weaver and Malone, 1979), (2) repeatedly on Iliamna volcano (Alaska) in association with glacial avalanches (Caplan-Auerbach and Huggel, 2007), (3) on Mt. Stellar (Alaska) prior to a 2006 rockfall (Huggel et al., 2010), and (4) as part of the Kausu landslide (Japan), in 2015 (Yamada et al., 2016). In all cases the precursory events exhibited waveform similarity, indicative of a repeating point of failure. These events represent stick-slip behavior at the landslide base. The precursory sequences last several hours, suggesting that detection of these events could provide a means of warning prior to failure. This may be useful in areas where instabilities or incipient failures are evident.

Vaccine-induced modulation of gene expression in turbot peritoneal cells. A microarray approach.

PubMed

Fontenla, Francisco; Blanco-Abad, Verónica; Pardo, Belén G; Folgueira, Iria; Noia, Manuel; Gómez-Tato, Antonio; Martínez, Paulino; Leiro, José M; Lamas, Jesús

2016-07-01

We used a microarray approach to examine changes in gene expression in turbot peritoneal cells after injection of the fish with vaccines containing the ciliate parasite Philasterides dicentrarchi as antigen and one of the following adjuvants: chitosan-PVMMA microspheres, Freund́s complete adjuvant, aluminium hydroxide gel or Matrix-Q (Isconova, Sweden). We identified 374 genes that were differentially expressed in all groups of fish. Forty-two genes related to tight junctions and focal adhesions and/or actin cytoskeleton were differentially expressed in free peritoneal cells. The profound changes in gene expression related to cell adherence and cytoskeleton may be associated with cell migration and also with the formation of cell-vaccine masses and their attachment to the peritoneal wall. Thirty-five genes related to apoptosis were differentially expressed. Although most of the proteins coded by these genes have a proapoptotic effect, others are antiapoptotic, indicating that both types of signals occur in peritoneal leukocytes of vaccinated fish. Interestingly, many of the genes related to lymphocytes and lymphocyte activity were downregulated in the groups injected with vaccine. We also observed decreased expression of genes related to antigen presentation, suggesting that macrophages (which were abundant in the peritoneal cavity after vaccination) did not express these during the early inflammatory response in the peritoneal cavity. Finally, several genes that participate in the inflammatory response were differentially expressed, and most participated in resolution of inflammation, indicating that an M2 macrophage response is generated in the peritoneal cavity of fish one day post vaccination. Copyright © 2016 Elsevier Ltd. All rights reserved.

2014 volcanic activity in Alaska: Summary of events and response of the Alaska Volcano Observatory

USGS Publications Warehouse

Cameron, Cheryl E.; Dixon, James P.; Neal, Christina A.; Waythomas, Christopher F.; Schaefer, Janet R.; McGimsey, Robert G.

2017-09-07

The Alaska Volcano Observatory (AVO) responded to eruptions, possible eruptions, volcanic unrest or suspected unrest, and seismic events at 18 volcanic centers in Alaska during 2014. The most notable volcanic activity consisted of intermittent ash eruptions from long-active Cleveland and Shishaldin Volcanoes in the Aleutian Islands, and two eruptive episodes at Pavlof Volcano on the Alaska Peninsula. Semisopochnoi and Akutan volcanoes had seismic swarms, both likely the result of magmatic intrusion. The AVO also installed seismometers and infrasound instruments at Mount Cleveland during 2014.

Publications - GMC 254 | Alaska Division of Geological & Geophysical

Science.gov Websites

and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a ARCO Alaska Inc. Cirque #2 well Authors: Unknown Publication Date: 1995 Publisher: Alaska Division of from cuttings (2,200-7,660') of the ARCO Alaska Inc. Cirque #2 well: Alaska Division of Geological &

Publications - GMC 272 | Alaska Division of Geological & Geophysical

Science.gov Websites

and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a ') from the ARCO Alaska Inc. Till #1 well Authors: Unknown Publication Date: 1996 Publisher: Alaska reflectance maceral data of cuttings (3,100-6,975') from the ARCO Alaska Inc. Till #1 well: Alaska Division of

Publications - GMC 255 | Alaska Division of Geological & Geophysical

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and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a ARCO Alaska Inc. Rock Flour #1 well Authors: Unknown Publication Date: 1995 Publisher: Alaska Division reflectance data from cuttings (1,600-7,170') of the ARCO Alaska Inc. Rock Flour #1 well: Alaska Division of

Publications - GMC 238 | Alaska Division of Geological & Geophysical

Science.gov Websites

and Facilities Staff Seismic and Well Data Data Reports Contact Us Frequently Asked Questions Ask a ARCO Alaska Inc. Fiord #1 well Authors: Unknown Publication Date: 1994 Publisher: Alaska Division of from cuttings (1,250-10,250') of the ARCO Alaska Inc. Fiord #1 well: Alaska Division of Geological &

Publications - GMC 388 | Alaska Division of Geological & Geophysical

Science.gov Websites

DGGS GMC 388 Publication Details Title: Core photographs of the Cominco DDH-1 through DDH-4 boreholes the Cominco DDH-1 through DDH-4 boreholes, NAP Cu-Zn Prospect, Dillingham Quadrangle, Alaska: Alaska Alaska's Mineral Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska

Publications - GMC 336 | Alaska Division of Geological & Geophysical

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Oil Company OCS Y-0197-1 (Tern Island #3) at the Alaska GMC Authors: Shell Oil Company, and Alaska information. Quadrangle(s): Alaska Statewide Bibliographic Reference Shell Oil Company, and Alaska Geological Materials Center, 2006, Core Photographs (12915'-13361.5') dated June 2003 of the Shell Oil Company OCS Y

Publications - PDF 98-36A | Alaska Division of Geological & Geophysical

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Oxides; Rocks; STATEMAP Project; Trace Elements Top of Page Department of Natural Resources, Division of Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical

Publications - RI 2015-7 | Alaska Division of Geological & Geophysical

Science.gov Websites

Surveys Skip to content State of Alaska myAlaska My Government Resident Business in Alaska content DGGS RI 2015-7 Publication Details Title: Surficial geology of the Tyonek area, south-central of the Tyonek area, south-central Tyonek Quadrangle, Alaska: Alaska Division of Geological &

Subsurface iceberg melt key to Greenland fjord freshwater budget

NASA Astrophysics Data System (ADS)

Moon, T.; Sutherland, D. A.; Carroll, D.; Felikson, D.; Kehrl, L.; Straneo, F.

2018-01-01

Liquid freshwater fluxes from the Greenland ice sheet affect ocean water properties and circulation on local, regional and basin-wide scales, with associated biosphere effects. The exact impact, however, depends on the volume, timing and location of freshwater releases, which are poorly known. In particular, the transformation of icebergs, which make up roughly 30-50% of the loss of the ice-sheet mass to liquid freshwater, is not well understood. Here we estimate the spatial and temporal distribution of the freshwater flux for the Helheim-Sermilik glacier-fjord system in southeast Greenland using an iceberg-melt model that resolves the subsurface iceberg melt. By estimating seasonal variations in all the freshwater sources, we confirm quantitatively that iceberg melt is the largest annual freshwater source in this system type. We also show that 68-78% of the iceberg melt is released below a depth of 20 m and, seasonally, about 40-100% of that melt is likely to remain at depth, in contrast with the usual model assumptions. Iceberg melt also peaks two months after all the other freshwater sources peak. Our methods provide a framework to assess individual freshwater sources in any tidewater system, and our results are particularly applicable to coastal regions with a high solid-ice discharge in Greenland.

Radar attenuation and temperature within the Greenland Ice Sheet

USGS Publications Warehouse

MacGregor, Joseph A; Li, Jilu; Paden, John D; Catania, Ginny A; Clow, Gary D.; Fahnestock, Mark A; Gogineni, Prasad S.; Grimm, Robert E.; Morlighem, Mathieu; Nandi, Soumyaroop; Seroussi, Helene; Stillman, David E

2015-01-01

The flow of ice is temperature-dependent, but direct measurements of englacial temperature are sparse. The dielectric attenuation of radio waves through ice is also temperature-dependent, and radar sounding of ice sheets is sensitive to this attenuation. Here we estimate depth-averaged radar-attenuation rates within the Greenland Ice Sheet from airborne radar-sounding data and its associated radiostratigraphy. Using existing empirical relationships between temperature, chemistry, and radar attenuation, we then infer the depth-averaged englacial temperature. The dated radiostratigraphy permits a correction for the confounding effect of spatially varying ice chemistry. Where radar transects intersect boreholes, radar-inferred temperature is consistently higher than that measured directly. We attribute this discrepancy to the poorly recognized frequency dependence of the radar-attenuation rate and correct for this effect empirically, resulting in a robust relationship between radar-inferred and borehole-measured depth-averaged temperature. Radar-inferred englacial temperature is often lower than modern surface temperature and that of a steady state ice-sheet model, particularly in southern Greenland. This pattern suggests that past changes in surface boundary conditions (temperature and accumulation rate) affect the ice sheet's present temperature structure over a much larger area than previously recognized. This radar-inferred temperature structure provides a new constraint for thermomechanical models of the Greenland Ice Sheet.

Alaska Plant Materials Center | Division of Agriculture

Science.gov Websites

Alaska Plant Materials Center Serving Alaska's needs in the production of native plants and traditional Division of Agriculture Grants Alaska Agriculture Statistics Annual Overview Invasive Plants Invasive Plants Program Invasives News Plant Profiles Canada thistle Elodea European Bird Cherry Giant hogweed

Meteoric 10Be as a tracer of subglacial processes and interglacial surface exposure in Greenland

NASA Astrophysics Data System (ADS)

Graly, Joseph A.; Corbett, Lee B.; Bierman, Paul R.; Lini, Andrea; Neumann, Thomas A.

2018-07-01

In order to test whether sediment emerging from presently glaciated areas of Greenland was exposed near or at Earth's surface during previous interglacial periods, we measured the rare isotope 10Be contained in grain coatings of sediment collected at five ice marginal sites. Such grain coatings contain meteoric 10Be (10Bemet), which forms in the atmosphere and is deposited onto Earth's surface. Samples include sediment entrained in ice, glaciofluvial sediment collected at the ice margin, and subglacial sediment extracted during hot water drilling in the ablation zone. Due to burial by ice, contemporary subglacial sediment could only have acquired substantial 10Bemet concentrations during periods in the past when the Greenland Ice Sheet was less extensive than present. The highest measured 10Bemet concentrations are comparable to those found in well-developed, long-exposed soils, suggesting subglacial preservation and glacial transport of sediment exposed during preglacial or interglacial periods. Ice-bound sediment has significantly higher 10Bemet concentrations than glaciofluvial sediment, suggesting that glaciofluvial processes are sufficiently erosive to remove tracers of previous interglacial exposures. Northern Greenland sites where ice and sediment are supplied from the ice sheet's central main dome have significantly higher 10Bemet concentrations than sites in southern Greenland, indicating greater preglacial or interglacial landscape preservation in central Greenland than in the south. Because southern Greenland has more frequent and spatially extensive periods of glacial retreat but nevertheless has less evidence of past subaerial exposure, we suggest that 10Bemet measurements in glacial sediment are primarily controlled by erosional efficiency rather than interglacial exposure length.