Analyse av Sentinel-1 data til deteksjon og varsling av kvikkleireskredet på Gjerdrum

Denne rapporten gir en oversikt over arbeidet gjort i prosjektet «Analyse av Sentinel-1 data i forkant av kvikkleireskredet på Gjerdrum». Prosjektets formål var å undersøke om backscatter data fra Sentinel-1 satellittene kan gi nyttig informasjon fra området rundt kvikkleireskredet i Gjerdrum i Desember 2020. En ønsker spesielt å finne ut om slike data i framtiden kan brukes til å detektere endringer i terrenget som har betydning for stabilitet og eventuelt kan brukes til varslingsformål.Analyse av Sentinel-1 data til deteksjon og varsling av kvikkleireskredet på GjerdrumpublishedVersio

Avalanche debris detection using satellite-borne radar and optical remote sensing

The mountainous fjord landscape around Tromsø in Northern Norway is prone to high avalanche activity during the snow season. Large avalanches pose a hazard to infrastructure, such as buildings and roads, located between the steep mountainsides and the fjords. To forecast the spatial and temporal extent of avalanche events, knowledge of past activity is critical. For this, a complete avalanche record is needed, however, difficult to achieve. We hypothesize, that the use of satellite data can assist in mapping avalanches over large areas. During and shortly after an intense avalanche cycle in the county of Troms in March 2014, we obtained 11 high-resolution Radarsat-2 Ultrafine scenes centered over large observed avalanches, together with one Landsat-8 scene and four Radarsat-2 SCN/SCW scenes with coarser resolution, covering the entire county. We detected avalanche debris-like features visually, by applying two detection algorithms that make use of the increased backscatter in avalanche debris. This backscatter increase is due to increased snow water equivalent and surface roughness. In addition to the multi-sensor approach using high- to mediumresolution satellite data, we also used a multi-temporal approach. Repeated acquisitions of satellite data from the same area enabled redetection of avalanche debris-like features by change detection methods and, thus, confirmation of their existence. In this study, we show the usability of satellite radar data in detecting avalanches over a large area with medium resolution. Since ultra-high resolution is not available in an operational context today, our hypothesis based on our results using Radarsat-2 is that the ESA Sentinel-1 satellite could provide sufficient coverage and resolution to detect medium and large sized avalanches

Saccharomyces cerevisiae single-copy plasmids for auxotrophy compensation, multiple marker selection, and for designing metabolically cooperating communities

Auxotrophic markers are useful tools in cloning and genome editing, enable a large spectrum of genetic techniques, as well as facilitate the study of metabolite exchange interactions in microbial communities. If unused background auxotrophies are left uncomplemented however, yeast cells need to be grown in nutrient supplemented or rich growth media compositions, which precludes the analysis of biosynthetic metabolism, and which leads to a profound impact on physiology and gene expression. Here we present a series of 23 centromeric plasmids designed to restore prototrophy in typical Saccharomyces cerevisiae laboratory strains. The 23 single-copy plasmids complement for deficiencies in HIS3, LEU2, URA3, MET17 or LYS2 genes and in their combinations, to match the auxotrophic background of the popular functional-genomic yeast libraries that are based on the S288c strain. The plasmids are further suitable for designing self-establishing metabolically cooperating (SeMeCo) communities, and possess a uniform multiple cloning site to exploit multiple parallel selection markers in protein expression experiments

Remote sensing of avalanches in northern Norway using Synthetic Aperture Radar

We present results from using synthetic aperture radar data (SAR) to analyse three avalanches in the county of Troms in northern Norway during the late snow season 2013. During a persistent polar low pressure activity at the end of March and the beginning of April 2013, inducing high precipitation rates in combination with high wind speeds, an extensive avalanche cycle took place in that area. Several avalanches released naturally causing fatalities, road closures and community evacuations. The main goal of our study was to investigate whether high resolution SAR could be used for detecting avalanche debris in the run-out zones. For validation purposes we used, among others, a high resolution camera operated on an Unmanned Airborne Vehicle (UAV) to acquire very accurate ortho-photos of the avalanches. The UAV-maps were of unprecedented resolution (~5 cm). The result of the analysis of the high resolution Radarsat-2 image showed that avalanches could be identified visually due to the high contrast between low radar backscatter from unperturbed snow and high backscatter (caused by increased surface roughness/snow mass) of the avalanche debris in the avalanche run-out zones. In order to assess the accuracy, the avalanche delineations were compared with results from UAV photos and photographs taken during helicopter reconnaissance flights right after the events. In two of three cases, a good correspondence was found between SAR delineated avalanches and outlines derived from optical data

UAV-BORNE UWB RADAR FOR SNOWPACK SURVEYS

Source at https://hdl.handle.net/11250/2649630In this report we summarize the capabilities and technical characteristics of our UAV-borne UWB radar system, designed for conducting snow surveys. We developed an ultrawideband snow sounder that is capable of imaging snow stratigraphy with a 5 cm range resolution. The radar can be carried by an octocopter UAV in order to carry out airborne snowpack surveys. During a demonstration on Andøya, we showed that the radar was capable of resolving snow stratigraphy in wet snow conditions, as well as detecting a buried person under 1.5 m of wet snow. In this report, we present the results of the demonstration in detail. We furthermore discuss capabilities and incapabilities of our radar system and offer a list of future steps to bring it to an operational status

Functional metabolomics describes the yeast biosynthetic regulome

Genome-metabolism interactions enable cell growth. To probe the extent of these interactions and delineate their functional contributions, we quantified the Saccharomyces amino acid metabolome and its response to systematic gene deletion. Over one-third of coding genes, in particular those important for chromatin dynamics, translation, and transport, contribute to biosynthetic metabolism. Specific amino acid signatures characterize genes of similar function. This enabled us to exploit functional metabolomics to connect metabolic regulators to their effectors, as exemplified by TORC1, whose inhibition in exponentially growing cells is shown to match an interruption in endomembrane transport. Providing orthogonal information compared to physical and genetic interaction networks, metabolomic signatures cluster more than half of the so far uncharacterized yeast genes and provide functional annotation for them. A major part of coding genes is therefore participating in gene-metabolism interactions that expose the metabolism regulatory network and enable access to an underexplored space in gene function

Snow avalanches in central Svalbard : a field study of meteorological and topographical triggering factors and geomorphological significance

Snow avalanches are a natural phenomenon occurring in snow covered alpine areas all over the world. A complex process combining gravity, topographical conditions, physical and mechanical properties of snow and meteorological conditions control avalanche release. Due to this process complexity, avalanche research has a remarkable interdisciplinary nature, from physical geography, to geomorphology, meteorology, geophysics, engineering and natural hazards. Hazard related avalanche research is of most importance, as an improved process understanding of how, when and where avalanches release is crucial for avalanche warning and forecasting. Besides this natural hazard focus, avalanches are also studied to improve the understanding of their geomorphological role. Their importance as rock sediment erosion, transport and depositional agents in high relief terrain is of main interest. Surveying the scientific literature indicates that until 2009 no basic avalanche research has been published in Svalbard. This is somewhat surprising, as the alpine Svalbard landscape with its snow cover, existing for a maximum of 10 months per year, is prone to avalanching. In addition, with the permanent settlement Longyearbyen, where the University Centre in Svalbard is located, infrastructure certainly exists to conduct year-round slope process studies, with very easy field access to avalanche terrain. Moreover there is an increasing population that is living and working in an active landscape, visited also by an increasing number of tourists. Therefore my PhD thesis is a field based and interdisciplinary study of the meteorological and topographical triggering factors and the geomorphological significance of avalanches in central Svalbard. All data was obtained by direct observations, data recording by instruments and by direct measurements in the field between 2003 – 2012; with my own data gathering beginning in 2008, but primarily during my 4 year PhD study from 2009 to 2012. Thus, it should be kept in mind, that results and conclusions are based on a short but unique dataset. The main characteristic of the snow climate in central Svalbard is a thin, discontinuous snowpack that is highly stratified with several ice layers and meltform layers overlying a persistent depth hoar base. Depth hoar and secondly facets are the most prominent weak layers in the snowpack. The main characteristic of the avalanche regime in central Svalbard is the dominance of cornice fall avalanches, due to the sedimentary plateau mountain topography, the lack of high vegetation and a prevailing winter wind direction. The timing of cornice fall avalanche releases is identified to be within 3-5 weeks after cornices start deforming rapidly enough that tension cracks open between the cornice and the snow of the plateau. Slab avalanches are the second most observed avalanche type. For the release of natural dry slab avalanches the best meteorological predictor variable are sums of precipitation and snowdrift in periods of 24, 48 and 72 hours before an avalanche day. This is in agreement with previous studies from other areas. Wet slab and slush avalanches had the longest runout distances observed. Such were studied during two midwinter wet avalanche extreme events in January 2010 and March 2011. Both these extreme cycles resulted from slowly passing low-pressure systems, with air temperatures several degrees above freezing, and 100-year record monthly rainfalls. Analyzing the occurrence of such extreme meteorological conditions for the last 100 years, no correlation between a warming climate and wet avalanche cycle frequency was found. In conclusion, low-pressure frequency and magnitude largely determine avalanche activity at present in Svalbard. As the low-pressure frequency is modeled to decline in the North Atlantic in a warming climate, avalanche activity will be reduced. However, cornice fall avalanches are mainly controlled by the topography and the prevailing winter wind direction, and will therefore increase in dominance. The geomorphological role of avalanches as sediment transport agents is significant, primarily due to rock erosion, transportation and deposition by the cornices and cornice fall avalanches. Cornices can increase rock weathering and thus erosion by keeping the ground thermal regime underneath them ideal for ice segregation. The weathered rock debris is then eroded from the backwall by plucking as the cornice detaches from the plateau. Cornice fall avalanches, consequently can transport rock debris downslope throughout winter and spring. Therefore, high rockwall retreat rates with associated large avalanche sedimentation on the avalanche fans below have been quantified for leeward facing slopes in Longyeardalen. This identified cornice fall avalanches as the most efficient geomorphological slope process at present and during the Holocene. The conducted research focusing on the natural hazard perspective and on the geomorphological effects of avalanches represents the first basic research on the natural phenomenon snow avalanche in central Svalbard. Hopefully my study will trigger more research on avalanches in Svalbard, but also be a useful basis for a future avalanche forecasting service in Svalbard

Snøskredaktivitet i Ramfjorden, Troms, 2014-2019

Vi detekterte automatisk skred i Sentinel-1 radarsatellittdata i et definert område på ca. 9.5 km2 i Ramfjorden og Lavangsdalen, Tromsø kommune. Sentinel-1 data var tilgjengelig i perioden 2014-2019 og vi har lastet ned 493 bilder der vi gjorde deteksjoner. Totalt detekterte vi 88 skred, hvorav 55 skred ble detektert i den østvendte fjellsiden av Blåfjellet i Ramfjorden, og resten på Henrikstinden i Lavangsdalen. Skredene på Blåfjellet stoppet alle langt opp i lia og var i den lavere persentilen av middels store skred. De største skredene detekterte vi på Henrikstinden i Lavangsdalen, hvorav de fleste ble detektert på fjellsiden som vender mot nord inn i Saltdalen. Det er flere usikkerhetsfaktorer tilknyttet fjernmålingsmetoden. Små skred kan ikke detektertes på grunn av den romlige oppløsningen av Sentinel-1 data. Det er også en mulighet for feildeteksjoner på grunn av terrengformasjoner som ligner på skred. Til slutt er det muligheter for at middels og store skred blir ikke detektert fordi vi prøver å skille skred som består av snø, fra uberørt snø rundt skredene. Gitt de angitte usikkerhetsfaktorene er det rimelig å anta at de aller fleste middels til store skredene som har gått ble detektert

Skreddeteksjon E69 Skarvbergtunnelen. (12/2018)

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