Automatic DEM generation for Antarctic terrain

first_imgAutomatic digital elevation model (DEM) generation has become an established technique within mapping agencies. This paper assesses the effectiveness of automatic DEM generation using area-based matching for glaciated terrain in Antarctica. DEM accuracy is assessed by comparison with check data acquired using analytical photogrammetry and independent field measurements.An optimum DEM collection strategy is identified. DEM success is linked to ground terrain type and it is found that areas of a DEM which can be collected successfully are relatively insensitive to changes in the collection strategy. A method of isolating unsuccessful areas of a DEM for manual editing is tested for Antarctic terrain. In this example, over 90% success is achieved in identifying erroneous DEM results measured against check datalast_img read more

ULF Pc5-6 magnetic activity in the polar cap as observed along a geomagnetic meridian in Antarctica

first_imgLatitudinal and diurnal distributions of spectral power and spatial coherency parameters of the geomagnetic variations in the Pc5-6 (1–6 mHz) frequency range are analyzed using data of magnetometer stations in Antarctica. The available stations give the possibility to form a latitude chain along the geomagnetic meridian 40°E stretching from magnetic latitude 69°S to 86°S. Long-period ULF activity at polar cap latitudes is characterized by lower amplitudes and wider spectra with lower central frequencies as compared with typical auroral Pc5 pulsations. The meridional distribution of average Pc5-6 spectral power is nonmonotonic and has a minimum near 80°. In general, the low-frequency broadband ULF activities in the polar cap and at auroral latitudes seem to be decoupled. This long-period ULF activity in the polar cap could be an image of wave activity in the tail lobes or the manifestation of turbulent component of the ionospheric convection at very high latitudes, but this requires further investigation.last_img read more

Factors that influence freezing in the sub-Antarctic springtail Tullbergia antarctica

first_imgEffects of 12 biotic and abiotic factors on the freezing point of the sub-Antarctic springtail, Tullbergia antarctica, were investigated. Repeated cooling of individual springtails five times resulted in very similar freezing points suggesting that ice nucleation in this freeze-susceptible species is likely to be initiated by intrinsic factors rather than being a stochastic event. Mean supercooling point (SCP) was influenced by cooling protocol, showing a linear increase in mean SCP with cooling rates from 8 to 0.1 °C min−1. However, the opposite effect (decreasing SCP) was seen with slower cooling. Slower rates may be ecologically realistic and allow time for appropriate physiological and biochemical changes. Feeding and food presence in the gut had no effect on SCP, and there was no correlation between the ice nucleating activity of bacteria isolated from the guts and the whole springtail SCP. Habitat altitude and diurnal light and temperature regimes also had no effect on SCP. There was no correlation between the cryoprotectant concentration of fresh animals and their SCP, but experimental desiccation resulted in increased osmolality and decreased SCP, although with considerable individual variation. The most significant influence on SCP was associated with ecdysis. As springtails cease feeding for a period either side of ecdysis, shedding the entire gut lining, moulting may be an efficient mechanism of clearing the gut of all ice nucleating material. This previously unrecognised relationship between ecdysis, cold tolerance and seasonal survival tactics may play an important role in over-winter survival of some arthropods.last_img read more

Breaking the ice: the introduction of biofouling organisms to Antarctica on vessel hulls

first_img1.Few reports exist that describe marine non-native species in the Southern Ocean and near-shore waters around the Antarctic continent. Nevertheless, Antarctica’s isolated marine communities, which show high levels of endemism, may be vulnerable to invasion by anthropogenically introduced species from outside Antarctica via vessel hull biofouling.2.Hull surveys of the British Antarctic Survey’s RRS James Clark Ross were undertaken between 2007 and 2014 at Rothera Research Station on the Antarctic Peninsula (Lat. 67°34’S; Long. 68°07’W) to investigate levels of biofouling. In each case, following transit through scouring sea-ice, over 99% of the vessel hull was free of macroscopic fouling communities. However, in some surveys microbial/algal biofilms, balanomorph barnacles and live individuals of the cosmopolitan pelagic barnacle, Conchoderma auritum were found in the vicinity of intake ports, demonstrating the potential for non-native species to be transported to Antarctica on vessel hulls.3.Increasing ship traffic volumes and declining duration of sea ice in waters to the north and west of the Antarctic Peninsula mean the region may be at increased risk of non-native species introductions. Locations at particular risk may include the waters around popular visitor sites, such as Goudier Island, Neko Harbour, Whalers Bay, Cuverville Island and Half Moon Island, and around northern peninsula research stations.4.Simple and cost-effective mitigation measures, such as intentionally moving transiting ships briefly through available offshore sea ice to scour off accessible biofouling communities, may substantially reduce hull-borne propagule pressure to the region. Better quantification of the risk of marine non-native species introductions posed by vessel hulls to both Arctic and Antarctic environments, as sea ice patterns and shipping traffic volumes change, will inform the development of appropriate regional and international management responses.last_img read more

Sedimentary processes on the continental slope off Kvitøya and Albertini troughs north of Nordaustlandet, Svalbard – The importance of structural-geological setting in trough-mouth fan development

first_imgNew marine-geophysical data were analyzed to investigate the sedimentary processes operating on the continental slope north of Nordaustlandet, Svalbard. Kvitøya Trough terminates in a trough-mouth fan (TMF) on the slope, whereas Albertini Trough incises the shelf edge and a TMF is notably absent. Instead, the continental slope beyond Albertini Trough is dominated by thick, acoustically stratified units likely formed by down-slope and along-slope sedimentological processes combined. The morphological and sedimentological differences between Albertini and Kvitøya troughs may partly be due to the larger dimensions of Kvitøya Trough and its associated glacial catchment area relative to Albertini, suggesting that the transport of a larger volume of glacigenic sediments potentially was a contributing factor in building Kvitøya TMF. By contrast, the downfaulted bedrock below outer Albertini Trough provided larger accommodation space for glacigenic sediments which accumulated in an outer-shelf basin, highlighting the importance of the structural-geological setting in TMF development. Debris-flow deposits and/or channel-levee deposits on the lower continental slope and rise off Kvitøya Trough indicate bypassing of glacigenic sediments from the shelf to the deep ocean, a process that is likely a result of locally steep slope gradients (< 9°). The volume of the Kvitøya TMF is smaller than TMFs along the western Svalbard margin, which may be linked to the more erosion-resistant bedrock of the northern margin and/or the comparatively small drainage basin of Kvitøya Trough compared to drainage basins of ice streams that drained westwards from Barents Sea. In addition, the Kvitøya TMF is incised by gullies indicating that they formed after Last Glacial Maximum (LGM) while larger tributary canyons flanking the Kvitøya TMF likely have developed during a longer time span. High seafloor backscatter values in the tributary canyons and gullies are interpreted as coarse-grained deposits that lead down-slope to debris-flow deposits, suggesting an origin for the tributary canyons and gullies through incision by gravity flows of sediment-laden meltwater during and/or after deglaciation.last_img read more

Diurnal cycle of coastal anthropogenic pollutant transport over southern West Africa during the DACCIWA campaign

first_imgDuring the monsoon season, pollutants emitted by large coastal cities and biomass burning plumes originating from Central Africa have complex transport pathways over Southern West Africa (SWA). The Dynamics–Aerosol–Chemistry–Cloud–Interactions in West Africa (DACCIWA) field campaign has provided numerous dynamical and chemical measurements in and around the super site of Savè in Benin (≈185km away from the coast), which allows quantifying the relative contribution of advected pollutants. Through the combination of in-situ ground measurements with aircraft, radio-sounding, satellite and high-resolution chemistry-transport modeling with the CHIMERE model, the source attribution and transport pathways of pollutants inland (here, NOx and CO) are carefully analyzed for the 1–7 July 2016 period. The relative contributions of different sources (i.e. emissions from several large coastal cities) on the air quality in Savè are characterized. It is shown that a systematic diurnal cycle exists with high surface concentrations of pollutants from 18:00 to 22:00UTC. This evening peak is attributed to pollution transport from the coastal city of Cotonou (Benin). Numerical model experiments indicates that the anthropogenic pollutants are accumulated during the day close to the coast, and transported northward as soon as the daytime convection in the atmospheric boundary layer ceases after 16:00UTC, reaching 8°N at 21:00UTC. When significant biomass burning pollutants are transported into continental SWA, they are mixed with anthropogenic pollutants along the coast during the day, and this mixture is then transported northward. At night, most of the coastal anthropogenic plumes are transported within the planetary boundary layer (below about 500m above ground level), whereas the biomass burning pollutants are mostly transported above it, thus generally not impacting ground level air quality.last_img read more

Prep Sports Roundup: 4/3

first_img Brad James Tags: Baseball/Beaver/Boys Soccer/Carbon/Delta/Gunnison/Manti/Millard/Monticello/North Sanpete/North Sevier/North Summit/Panguitch/Providence Hall/Richfield/Softball/South Sevier FacebookTwitterLinkedInEmailBoys SoccerRegion 14HERRIMAN, Utah-Jager Springer and Sam Clark each scored as the Delta Rabbits doubled up Providence Hall 2-1 in Region 14 boys soccer action Tuesday.Region 15RICHFIELD, Utah-Carlos Navarro scored twice and the North Sanpete Hawks blanked Richfield 3-0 Tuesday in Region 15 boys soccer action. Dentley Talbott also scored for the Hawks and Mario Hernandez posted the shutout for North Sanpete.MONROE, Utah-Brian Chavez and Julio Carrasco each scored as the Manti Templars doubled up South Sevier 2-1 in Region 15 b0ys soccer action Tuesday. Mario Carrillo scored in the loss for the Rams.Softball2-A CentralSALINA, Utah-Maddie Edwards went yard twice and the Gunnison Bulldogs pounded North Sevier 13-1 in 2-A North softball action Tuesday.2-A SouthPANGUITCH, Utah-Bailee Hunter doubled and tripled and the Beaver Beavers routed Panguitch 24-0 Tuesday in 2-A South softball action.Region 15MANTI, Utah-Addelyn Brotherson went yard and doubled, helping the North Sanpete Hawks to an 8-2 win over Manti in Region 15 softball action Tuesday.Non-RegionMONROE, Utah-Cali Fossat hit three homers, amassing 8 RBI overall, as the Carbon Dinos smacked South Sevier 27-9 Tuesday in non-region softball action.Baseball2-A NorthCOALVILLE, Utah-Parx Bartholomew went yard three times and the Gunnison Bulldogs routed North Summit 15-0 in 2-A North baseball action Tuesday. Bowen Jensen added three doubles and picked up the win on the mound for the Bulldogs.MONTICELLO, Utah-Burke Mickelsen homered twice and Rocky Bringhurst added a pair of doubles as the North Sevier Wolves decimated Monticello 23-3 Tuesday in 2-A North baseball action. Hunter Higgs, Ryan Delgado and Shawn Sorensen also homered for the Wolves, with Stockton Andersen adding three doubles. Higgs, Delgado, Mickelsen and Brody Butler also added doubles in the rout for the Wolves.2-A SouthFILLMORE, Utah-Crayton Hollingshead and Hunter Hafen each doubled and the Beaver Beavers got past Millard 9-6 in 2-A South baseball action Tuesday. Tyce Raddon took the win on the mound for the Beavers. Written by April 3, 2018 /Sports News – Local Prep Sports Roundup: 4/3last_img read more

Prep Sports Roundup: 4/23

first_img Brad James Region 18 MT. PLEASANT, Utah-Addelyn Brotherson, Aubree Ison and Nakiah Taylor all homered, but it wasn’t enough as North Sanpete lost to Grantsville 7-5 Tuesday in non-region softball action. Kelby Henry added a double in the loss for the Hawks. Region 15 BEAVER, Utah-Jesus Magana netted a hat trick as the Beaver Beavers outlasted Gunnison Valley 3-2 Tuesday in Region 15 boys soccer action. Brandon Tucker and Bryan Ruiz each scored for the Bulldogs in the loss. 2-A South BEAVER, Utah-Bryson Barnes went yard and the Milford Tigers gashed Beaver 9-3 in 2-A South baseball action Tuesday. Zach Sherwood took the win on the mound for Milford. Ryker Albrecht homered in the loss for the Beavers PANGUITCH, Utah-Enterprise routed Panguitch 18-2 to complete a 2-A South softball doubleheader Tuesday. RICHFIELD, Utah-Emmitt Hafen earned the win on the mound, pitching six innings and amassed three RBI on as many hits as the Richfield Wildcats routed South Sevier 12-2 Tuesday in Region 15 baseball action. Morgan Albrecht added two hits in as many as bats, including a home run, for the Wildcats. Richfield improved to 10-0 in region play with the win and has earned a share of the Region 15 title. The loss dropped the Rams to 5-6 in region play. KANAB, Utah-Kiarra Gurr went yard and Madison Mathews earned the win in ther circle as the Parowan Rams surged past Kanab 18-12 in 2-A South softball action Tuesday. 2-A Central CASTLE DALE, Utah-Jentry Young homered and doubled twice as the Manti Templars routed Emery 17-7 Tuesday in Region 15 softball action. Lexie Alder, Sadie Cox and Tiffany Hermansen all addd doubles in the win for Manti. JUNCTION, Utah-Alissa Bosshardt tripled, Allie Cowley doubled and the North Sevier Wolves ran away from Piute 12-4 in 2A Central region softball Tuesday. Cowley also earned the win inside the circle for the Wolves. RICHFIELD, Utah-Brady Jacobson, Jesus Tapia and Luis Rodriguez each scored as the North Sanpete Hawks outlasted Richfield 3-2 in Region 15 boys soccer action Tuesday. Kordell Morgan and Max Kemp each scored in the loss for the Wildcats. Tags: Emmitt Hafen/Morgan Albrecht/Richfield Wildcats/South Sevier BEAVER, Utah-Brittlyn Carter and Madi Robinson each tripled as the Beaver Beavers pounded Milford 22-0 Tuesday in 2-A South softball action. Lindsey Smith and Tavy Gale each added doubles in the win for Beaver. Robinson earned the win in the circle for the Beavers. Softball Non-Region Region 14 April 23, 2019 /Sports News – Local Prep Sports Roundup: 4/23 FILLMORE, Utah-Kennedy Knudsen and Paige King each homered as the Gunnison Valley Bulldogs decimated Millard 21-0 in 2-A Central softball action Tuesday. Knudsen added a pair of doubles and Kezzley Winn tripled for the Bulldogs. Additionally, Gracy Christenson doubled and earned the win in the circle, while Jaida King, Katelynn Cherry, McKaylyn Edwards and Tayler Brackett also doubled in the win for Gunnison Valley. FacebookTwitterLinkedInEmailBaseball Boys Soccer RICHFIELD, Utah-Allie Torgerson earned the win in the circle as the Richfield Wildcats stymied South Sevier 4-1 in Region 15 softball action Tuesday. 2-A South KANAB, Utah-Carter Jackman and Drew Hafen doubled as the Kanab Cowboys pounded Parowan 11-1 Tuesday in 2-A South baseball action. Marcus Fox earned the win on the mound for the Cowboys. Region 15 HERRIMAN, Utah-David Thurston amassed a hat trick as the Providence Hall Patriots smacked Juab 8-0 in Region 14 boys soccer action Tuesday. Dante Montgomery earned the shutout for Providence Hall. Region 14 LINDON, Utah-Taylor Farnsworth scored twice and the Maeser Prep Lions humbled Delta 4-0 Tuesday in Region 14 boys soccer action. Josh Lewis earned the shutout in victory for Maeser. Region 15 2-A Central GUNNISON, Utah-Creed Mogle, Kolton Petersen, Parx Bartholomew and Shea Anderson each doubled as the Gunnison Valley Bulldogs routed Monticello 19-6 in 2-A Central baseball action Tuesday. Petersen earned the win on the mound for the Bulldogs. FILLMORE, Utah-Rylan Crane and Stockton Andersen each doubled as the North Sevier Wolves bested Millard 7-4 Tuesday in 2-A Central baseball action. Burke Mickelsen took the win on the mound for North Sevier. PANGUITCH, Utah-Kangie Bundy took the win in the circle as the Enterprise Wolves pounded Panguitch 24-0 Tuesday in the first game of a 2-A South softball doubleheader. Written by NEPHI, Utah-Madison Myers homered and doubled, leading the Juab Wasps to a 15-0 win over Providence Hall in Region 14 softball action Tuesday. Reggie Myers tripled twice and added a double for the Wasps. Additionally, Ashlyn Dansie doubled and tripled for the Wasps while Raygen Newton doubled twice for Juab. Saydi Anderson earned the win in the circle for the Wasps.last_img read more

Heisman contender Tua Tagovailoa carted off with season-ending hip injury

first_imgNovember 16, 2019 /Sports News – National Heisman contender Tua Tagovailoa carted off with season-ending hip injury Written by FacebookTwitterLinkedInEmailPhoto by Phil Ellsworth / ESPN Images(TUSCALOOSA, Ala.) — Alabama quarterback Tua Tagovailoa will miss the rest of the season after suffering a dislocated hip with a posterior wall fractureduring Saturday’s game against Mississippi State. He was later airlifted to Birmingham for CAT scans and MRIs.Doctors are continuing to evaluate the severity of the injury.With three minutes left in the first half, Tagovailoa was taken down by a pair of MSU defenders. He was unable to put pressure on his right leg as trainers helped him to his feet.He also suffered a bloody nose on the play.Alabama head coach Nick Saban told ESPN’s Molly McGrath that Tagovailoa was set to come out of the game following that drive. Saban had kept him in the game to practice a two-minute drill.Alabam was leading 35-7 at the time. “We’ve got to block them better so he doesn’t get sacked,” Saban added. “It’s too bad.”McGrath reported that Tagovailoa was screaming in pain as he was lifted onto the cart.Saban later called the injury “probably something that could be serious.”Tagovailoa was considered a serious contender for the Heisman Trophy this season, and could be a top-10 pick in next year’s NFL Draft. Earlier this year he missed one game after undergoing surgery on an ankle injury.Copyright © 2019, ABC Audio. All rights reserved.center_img Beau Lundlast_img read more

Brewton leads Coastal Carolina past Utah, 79-57

first_img FacebookTwitterLinkedInEmailCONWAY, S.C. (AP) — Keishawn Brewton scored 22 points and hit six 3-pointers, and Coastal Carolina beat Utah 79-57 on Thursday night in a Myrtle Beach Invitational quarterfinal.Ebrima Dibba added 19 points, DeVante’ Jones had 16 points and Garrick Green finished with 12 for the Chanticleers (3-2). Playing on their home court, they shot 45%, hit 11 3-pointers and pulled away midway through the second half with a Brewton-led 26-9 run.Timmy Allen had 15 points for the Utes (3-1), who never led outside of the opening 6 minutes but pulled to 44-38 on Jaxon Brenchley’s layup with 16½ minutes remaining.Brewton hit four 3s during that game-breaking run, which Dibba capped with a free throw that made it 70-47 with 5:53 to play.Utah — which entered shooting 40% from 3-point range — shot just 18% from long distance and matched a season low with five of them. The Utes shot just 25% in the second half.BIG PICTURECoastal Carolina: The Chanticleers looked right at home playing on their home floor — especially Brewton, a junior college transfer who’s making an immediate impact with his new team after scoring 24 in the opening loss to Campbell. Coastal Carolina shot 50% in the second half and made the most of their takeaways, turning 15 Utah turnovers into 19 points.Utah: It’s hard to sugarcoat this loss for a young Utes team that started 3-0 with solid wins at Nevada and against Minnesota and set the school’s single-game scoring record with 143 points against Mississippi Valley State. Both Gach, who averages 17.7 points, finished with five on 2-of-11 shooting.UP NEXTCoastal Carolina: Faces No. 24 Baylor on Friday in a semifinal.Utah: Will play Ohio on Friday in a consolation game. Tags: Coastal Carolina Chanticleers/Keishawn Brewton/Utah Runnin’ Utes Basketball Associated Press Written by November 21, 2019 /Sports News – Local Brewton leads Coastal Carolina past Utah, 79-57last_img read more