scholarly journals Glaciological Studies in Iceland with Erts-I Imagery

1975 ◽  
Vol 15 (73) ◽  
pp. 465-466 ◽  
Author(s):  
Richard S. Williams ◽  
ÁgÚst Bödvarsson ◽  
SigurjÓn Rist ◽  
KristjÁn SÆmundsson ◽  
Sigurdur Thorarinsson
Keyword(s):  
Late Summer ◽  
Time Lapse ◽  
Structural Features ◽  
List Type ◽  
Outlet Glacier ◽  
Glacial Ice ◽  
Ice Caps ◽  
North East ◽  
The North ◽  
Geothermal Activity

Under a long-term, bi-national, multi-disciplinary research project between the U.S. Geological Survey and various Icelandic scientific organizations, MSS imagery from the ERTS-I satellite is being used to study the varied dynamic environmental phenomena of Iceland, including its glaciers and ice caps. Initial analysis of the ERTS-I imagery has shown the importance of the repetitive imagery to: Record relatively short-term glaciological changes. According to measurements made on two ERTS-I images, taken 11 months apart, an outlet glacier in the north-east part of Vatnajökull, had surged 1.8 km. A combination of field observations and analysis of ERTS imagery shows a total surge in excess of 3 km which probably took place in a few months, perhaps in as little as a few weeks. Contorted moraines on another of Vatnajökull’s outlet glaciers, Skeiðararjökull, on the south-east coast, show a movement of 600 m in an 11 month period even though the snout of the glacier remained in essentially the same position. Several glacier-margin lakes have been observed to change in size during the year (1972-73), particularly Grjœnalón, which continued to enlarge in area each time it was imaged until its size diminished markedly after a jökulhlaup partially emptied the lake in August 1973. Seasonal changes in the size of sediment plumes along the coast, where glacial rivers debouch their sediment-laden water into the ocean, can also be observed in a time-lapse manner. Furnish the data necessary to revise certain glaciological features on maps, and to produce ortho-image maps of ice caps directly from ERTS imagery, at least to map scales of 1: 250 000. Sufficient ERTS-I imagery of Iceland from the late summer and early fall of 1973 now exists to map accurately, from a planimetric standpoint, 90% of that area of Iceland covered by glacial ice (previously estimated to be 11.5% of total area of Iceland). Optimum imagery (minimum snow cover, maximum exposure of glacial ice) has been obtained of Vatnajökull, Langjrikull, Hofsjökull, Myrdalsjökull, and Eyjafjallajökull or five (including the four biggest) of the seven largest ice caps in Iceland and five of the smaller (less than 50 km2) ice caps as well. On 19 August 1973 Hofsjökull had an area of 915 km- on ERTS imagery. Its area has usually been cited as 996 km2. On a 1945 Danish Geodetic Institute map (1: 500 000) the area is 981 km2; U.S. Army maps (1 : 250 000, 1969) show an area of 943 km2. Map subglacial volcanic and structural features. Within or at the margins of the ice caps and outlet glaciers, a number of new glaciological, structural, and volcanic features can be mapped from ERTS-I imagery, particularly at low solar illumination angles (<10°) including several probable subglacial central volcanoes, calderas, and tectonic lineaments. Some of the effects of jökulhlaups can be mapped, including subsidence cauldrons resulting from subglacial volcanic or intense geothermal activity.

scholarly journals Glaciological Studies in Iceland with Erts-I Imagery

1975 ◽  
Vol 15 (73) ◽  
pp. 465-466
Author(s):  
Richard S. Williams ◽  
Ágúst Bödvarsson ◽  
Sigurjón Rist ◽  
Kristján Sæmundsson ◽  
Sigurdur Thorarinsson
Keyword(s):  
Late Summer ◽  
Time Lapse ◽  
Structural Features ◽  
List Type ◽  
Outlet Glacier ◽  
Glacial Ice ◽  
Ice Caps ◽  
North East ◽  
The North ◽  
Geothermal Activity

Under a long-term, bi-national, multi-disciplinary research project between the U.S. Geological Survey and various Icelandic scientific organizations, MSS imagery from the ERTS-I satellite is being used to study the varied dynamic environmental phenomena of Iceland, including its glaciers and ice caps. Initial analysis of the ERTS-I imagery has shown the importance of the repetitive imagery to: Record relatively short-term glaciological changes. According to measurements made on two ERTS-I images, taken 11 months apart, an outlet glacier in the north-east part of Vatnajökull, had surged 1.8 km. A combination of field observations and analysis of ERTS imagery shows a total surge in excess of 3 km which probably took place in a few months, perhaps in as little as a few weeks. Contorted moraines on another of Vatnajökull’s outlet glaciers, Skeiðararjökull, on the south-east coast, show a movement of 600 m in an 11 month period even though the snout of the glacier remained in essentially the same position.Several glacier-margin lakes have been observed to change in size during the year (1972-73), particularly Grjœnalón, which continued to enlarge in area each time it was imaged until its size diminished markedly after a jökulhlaup partially emptied the lake in August 1973. Seasonal changes in the size of sediment plumes along the coast, where glacial rivers debouch their sediment-laden water into the ocean, can also be observed in a time-lapse manner.Furnish the data necessary to revise certain glaciological features on maps, and to produce ortho-image maps of ice caps directly from ERTS imagery, at least to map scales of 1: 250 000. Sufficient ERTS-I imagery of Iceland from the late summer and early fall of 1973 now exists to map accurately, from a planimetric standpoint, 90% of that area of Iceland covered by glacial ice (previously estimated to be 11.5% of total area of Iceland). Optimum imagery (minimum snow cover, maximum exposure of glacial ice) has been obtained of Vatnajökull, Langjrikull, Hofsjökull, Myrdalsjökull, and Eyjafjallajökull or five (including the four biggest) of the seven largest ice caps in Iceland and five of the smaller (less than 50 km2) ice caps as well. On 19 August 1973 Hofsjökull had an area of 915 km- on ERTS imagery. Its area has usually been cited as 996 km2. On a 1945 Danish Geodetic Institute map (1: 500 000) the area is 981 km2; U.S. Army maps (1 : 250 000, 1969) show an area of 943 km2.Map subglacial volcanic and structural features. Within or at the margins of the ice caps and outlet glaciers, a number of new glaciological, structural, and volcanic features can be mapped from ERTS-I imagery, particularly at low solar illumination angles (<10°) including several probable subglacial central volcanoes, calderas, and tectonic lineaments. Some of the effects of jökulhlaups can be mapped, including subsidence cauldrons resulting from subglacial volcanic or intense geothermal activity.

Observations on the Quaternary geology around Nioghalvfjerdsfjorden, eastern North Greenland

1999 ◽  
pp. 56-60
Author(s):  
Ole Bennike ◽  
Anker Weidick
Keyword(s):  
Late Summer ◽  
Open Water ◽  
Quaternary Geology ◽  
Mean Annual Precipitation ◽  
Outlet Glacier ◽  
Ice Caps ◽  
North East ◽  
Pack Ice ◽  
Lake Deposits ◽  
North Greenland

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Bennike, O., & Weidick, A. (1999). Observations on the Quaternary geology around Nioghalvfjerdsfjorden, eastern North Greenland. Geology of Greenland Survey Bulletin, 183, 56-60. https://doi.org/10.34194/ggub.v183.5205 _______________ In North and North-East Greenland, several of the outlet glaciers from the Inland Ice have long, floating tongues (Higgins 1991). Nioghalvfjerdsfjorden (Fig. 1) is today occupied by a floating outlet glacier that is about 60 km long, and the fjord is surrounded by dissected plateaux with broad valleys (Thomsen et al. 1997). The offshore shelf to the east of Nioghalvfjerdsfjorden is unusually broad, up to 300 km wide (Cherkis & Vogt 1994), and recently small low islands were discovered on the western part of this shelf (G. Budeus and T.I.H. Andersson, personal communications 1998). Quaternary deposits are widespread around Nioghalvfjerdsfjorden and include glacial, glaciofluvial, marine, deltaic and ice lake deposits. Ice margin features such as kame deposits and moraines are also common (Davies 1972). The glaciation limit increases from 200 m a.s.l. over the eastern coastal islands to 1000 m in the inland areas; local ice caps and valley glaciers are common in the region, although the mean annual precipitation is only about 200 mm per year. Most of the sea in the area is covered by permanent sea ice, with pack ice further east, but open water is present in late summer in some fjords north of Nioghalvfjerdsfjorden, and in the Nordøstvandet polynia.

scholarly journals The first 6 weeks – setting up a UK urgent dental care centre during the COVID-19 pandemic

2020 ◽  
Author(s):  
Emily Carter ◽  
Charlotte C Currie ◽  
Abisola Asuni ◽  
Rachel Goldsmith ◽  
Grace Toon ◽  
...  
Keyword(s):  
Dental Care ◽  
Care Service ◽  
Clinical Care ◽  
Service Evaluation ◽  
Urgent Care ◽  
List Type ◽  
Care Centre ◽  
North East ◽  
The North ◽  
Patient Pathways

AbstractIntroductionThe COVID-19 pandemic has posed many challenges, including provision of urgent dental care. This paper presents a prospective service evaluation during establishment of urgent dental care in the North-East of England over a six-week period.AimTo monitor patient volumes, demographics and outcomes at the North-East urgent dental care service and confirm appropriate care pathways.Main Outcome MethodsData were collected on key characteristics of patients accessing urgent care from 23rd March to 3rd May 2020. Analysis was with descriptive statistics.ResultsThere were 1746 patient triages, (1595 telephone and 151 face-to-face) resulting in 1322 clinical consultations. The most common diagnoses were: symptomatic irreversible pulpitis or apical periodontitis. 65% of clinical consultations resulted in extractions, 0.5% an aerosol generating procedure. Patients travelled 25km on average to access care, however this reduced as more urgent care centres were established. The majority of patients were asymptomatic of COVID-19 and to our knowledge no staff acquired infection due to occupational exposure.ConclusionThe urgent dental care centre effectively managed urgent and emergency dental care, with appropriate patient pathways established over the 6-week period. Dental preparedness for future pandemic crisis could be improved and informed by this data.Three In Brief PointsA summary is given of how urgent dental care was established in the North East of England during the COVID-19 pandemic which may help with future preparedness for pandemics.Aerosol generating procedures were almost always avoided in the delivery of urgent dental careA telephone triage system was effectively used to determine who needed clinical care, and to separate symptomatic, asymptomatic and shielding patients, with very few failures in triage noted.

The structural characteristics of the Strathspey Complex, Inverness-shire

1970 ◽  
Vol 107 (3) ◽  
pp. 201-215 ◽  
Author(s):  
T. E. Smith
Keyword(s):  
High Temperatures ◽  
Structural Characteristics ◽  
Structural Features ◽  
Detailed Account ◽  
North East ◽  
The North ◽  
Granite Emplacement ◽  
Separate Event ◽  
Tectonic Environment

SummaryA detailed account is given of the structural features of the Strathspey Granite and Pegmatite Complex together with information about the metamorphic and tectonic environment of the surrounding metasediments. The evidence indicates that the granite core of the complex was intruded shortly after the latest phase of folding recorded in the area had taken place. The country rocks were still at relatively high temperatures at the time of intrusion and were deformed by the granite. The granite emplacement is also shown to be a separate event not directly connected with the formation of the regional migmatite complex, which extends for 48 km to the north-east.

scholarly journals Geothermal potential mapping of Northeast Morocco (Bekrane-Ahfir) using remote sensing data and GIS

2021 ◽  
Vol 234 ◽  
pp. 00093
Author(s):  
Intissar El Morabit ◽  
Soufiane Maimouni ◽  
Ahmed Fekri
Keyword(s):  
Remote Sensing ◽  
Active Sites ◽  
Remote Sensing Data ◽  
Landsat 8 ◽  
North East ◽  
The North ◽  
Hydrothermal Springs ◽  
Geothermal Potential ◽  
Geothermal Activity ◽  
Potential Mapping

Geothermal energy is part of the renewable energy mix. It is used for heating, air conditioning and sometimes even for the production of electricity. Prospecting for such a resource proves to be a difficult and capital-intensive task. To overcome this constraint, we have used remote sensing which is an adequate tool to guide the prospecting through the elaboration of hydrothermal resource potential maps at the level of zones that present a favorable potential for exploitation (hyper-tectonized sites, volcanic sites, faulted sites, sites with hot geological formations, seismic zones...). The objective of this work is to carry out a study on the North-East of Morocco (Berkane Province), in order to identify favorable sites for geothermal exploitation such as geologically and hydrogeologically active sites. The methodology adopted consists in processing the images of the OLI (Operational Land Imager) and TIRS (Thermal Infrared Sensor) sensors of the Landsat-8 satellite in order to extract spectral indices (Clay mineral Index and Ferrous mineral Index,) detecting a geothermal activity and the surface temperature map (LST) using muticriteria analysis method (MCA). ) in the north-eastern part of Morocco. The results obtained show an almost perfect concordance of the distribution of the above-mentioned indices, with the map of lineaments which are considered as heat drains from the depth to the surface. Moreover, a correct correlation was established during the validation of these results with the map of the inventory of hydrothermal springs identified in the study area.

The biology of the ommastrephid squid, Todarodes sagittatus, in the north-east Atlantic

2001 ◽  
Vol 81 (2) ◽  
pp. 299-306 ◽  
Author(s):  
Colm Lordan ◽  
Martin A. Collins ◽  
Linda N. Key ◽  
Eoin D. Browne
Keyword(s):  
Adult Life ◽  
Late Summer ◽  
Maximum Size ◽  
The West ◽  
Fish Prey ◽  
Potential Fecundity ◽  
North East ◽  
The North ◽  
Important Prey ◽  
Daily Increments

Todarodes sagittatus (N=1131) were opportunistically sampled from commercial and research trawling in Irish and Scottish waters between 1993 and 1998. The results suggest that the species is common in deep waters (>200 m) to the west of Ireland and Scotland, particularly in late summer and autumn. The size of squid caught was related to depth, with larger squid caught deeper, and is indicative of an ontogenetic, bathymetric migration. Females were more common (sex ratio 1·00:0·46), and attained a larger maximum size (520 mm mantle length (ML)) than males (426 mm ML). Mature females (360–520 mm ML) were caught in deep water (>500 m), between March and November, with a large catch of mature females taken off the west coast of Ireland in August 1996. Mature males (300–426 mm) were found from August to November. Potential fecundity was estimated to range from 205,000–523,500 eggs female−1. Putative daily increments in statoliths indicated a life cycle of slightly over a year, with rapid growth of approximately 1·8 mm d−1 during subadult and adult life. Fish were the most important prey of T. sagittatus and 17 fish prey taxa were identified, of which pelagic species were the most important.

scholarly journals The Creep of Ice, Geothermal Heat Flow, and Roosevelt Island, Antarctica

1980 ◽  
Vol 25 (91) ◽  
pp. 47-60 ◽  
Author(s):  
Robert H. Thomas ◽  
Douglas R. MacAyeal ◽  
Charles R. Bentley ◽  
James L. Clapp
Keyword(s):  
Linear Increase ◽  
List Type ◽  
Geothermal Heat ◽  
North East ◽  
The North ◽  
Movement Data ◽  
Polycrystalline Ice ◽  
Oriented Polycrystalline ◽  
Ice Velocity ◽  
Image Position

Abstract Measurements of ice velocity, thickness, and surface topography on the large ice rise known as Roosevelt Island are consistent with Glen’s flow law, , for values of τ between 5 × 104 N m–2 and 1.4 × 105 N m–2, and there is no indication of a reduction in n at low stresses. If n = 3 there must be progressive softening of the ice towards the edge of the ice rise, and this probably represents the combined effects of warming and recrystallization leading to a fabric favoring shear. Assuming that near the centre of the ice rise, where the effects of recrystallization are probably negligible, the ice behaves in the same way as randomly-oriented polycrystalline ice, then the geothermal flux G in this area is approximately 0.06 W m–2. In the absence of measurements of deep-ice temperatures, the distribution of G across the ice rise cannot be determined. However, the simplest interpretation of the movement data requires: (1) a linear increase in G from 0.05 W m–2 on the north-east side of Roosevelt Island to 0.07 W m–2 in the south-west, and (2) strain-rate enhancement, due to recrystallization, that increases outward from the centre of the ice rise to reach a maximum value of approximately two near the edges. The calculated values of G are larger than the world average, but this is consistent with the probably granitic core beneath Roosevelt Island. An increase in G of 0.02 W m–2 in a distance of 60 km would require an increase in granite thickness of about 5 km.

scholarly journals Glaciological and climatological investigations at Qamanârssûp sermia, West Greenland

1983 ◽  
Vol 115 ◽  
pp. 111-115
Author(s):  
R.J Braithwaite
Keyword(s):  
Late Summer ◽  
West Greenland ◽  
North East ◽  
The North ◽  
Similar Report ◽  
Field Report ◽  
Sketch Map ◽  
Inventory Number

As part of the GGU programme of investigations in connection with hydropower in West Greenland, glaciological and dimatological measurements were continued at Qamanârssâp sermia (inventory number 1CH21002) in 1982. The station was first established in late summer 1979 so that records for three complete summers 1980-1982 are now available. Brief reports on the work have been given by Olesen (1981) and Olesen & Braithwaite (1982) while a more detailed field report and data summary for 1979-1981 is given by Braithwaite & Olesen (1982). A similar report for 1982 is now in preparation. The sketch map in figure 44 shows the lower glacier together with locations of stakes and survey points. It should be noted that the three highest stakes, numbered 013, 015 and 016, are located off the map to the north-east of Stake 012.

scholarly journals The Glacial Drifts of the Leinster Mountains

1949 ◽  
Vol 1 (05) ◽  
pp. 220-225 ◽  
Author(s):  
A. Farrington
Keyword(s):  
Ice Sheets ◽  
The Other ◽  
North West ◽  
Ice Caps ◽  
North East ◽  
The North ◽  
Local Origin ◽  
Five Phases

AbstractFive glacial phases are recognized in the area described. Two of these are represented by the deposits of ice-sheets from the north-east and north-west respectively; the other three were of local origin. The materials composing the drifts differ sufficiently to enable the stratigraphy to be seen clearly. This shows that the local ice caps alternated with the invading ice sheets—which brings out a point of considerable climatological interest in that it is clear that the local ice advanced not simultaneously with the invading ice sheets but alternated with them. The order in which the five phases occurred is well established, but the importance of the intervals between the phases is at present uncertain.

scholarly journals IX-XII. FOSSIL LOCALITIES, FAUNAL LISTS & INDEX OF BRACHIOPOD GENERA AND SPECIES

1962 ◽  
Vol 3 (1) ◽  
pp. 255-256
Keyword(s):  
List Type ◽  
The South ◽  
North West ◽  
Eastern Side ◽  
North East ◽  
The North ◽  
North Side ◽  
South West ◽  
North Bank

ExcerptFossil collections have been obtained from a large number of localities in the Girvan area. Most of them have been referred to in the text, but those described below are localities from which figured material and types have been obtained.(a) AUCHENSOUL LIMESTONE AND CONFINIS FLAGS(1) Red mudstones and limestone breccias exposed on the south bank of the River Stinchar, 100 yards east of the bridge leading to Auchensoul Farm, 1i88 miles out of Barr on the Pinmore road (Auchensoul Limestone and Mudstones, Auchensoul Bridge).(2) Brown- and yellow-weathering calcareous confinis siltstones exposed on the hillside, 100 yards west of Struit Well, 300 yards west-north-west of Kirkdominae ruins on the north side of the Stinchar Valley, 1i89 miles west of Barr (confinis Flags, Kirkdominae Hill).(3) Brown-weathering calcareous confinis siltstones exposed in the bank of the pathway leading from the old limekiln to the quarry excavated in Stinchar Limestone, 450 yards west-south-west of Minuntion Farm on the north side of the River Stinchar and about 1i89 miles north-east of Pinmore bridge (confinis Flags, Minuntion).(4) Yellow-weathering, pebbly siltstones and impure nodular limestones transitional from confinis Flags to Stinchar Limestone, exposed on the eastern side of the water-filled quarry 300 yards south-west of Bougang Farm, 3 miles east of Ballantrae on the ColmoneU road (top of the confinis Flags, Bougang).(b) STINCHAR LIMESTONES AND SUPERSTES MUDSTONES (1) Mudstones with nodular limestones exposed on the north bank of the Water of Gregg, half a mile east of its junction with the

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