MSGID: 1:317/3 64af7e09   
   PID: hpt/lnx 1.9.0-cur 2019-01-08   
   TID: hpt/lnx 1.9.0-cur 2019-01-08   
    New radar technique lets scientists probe invisible ice sheet region on   
   Earth and icy worlds    
      
     Date:   
         July 12, 2023   
     Source:   
         University of Texas at Austin   
     Summary:   
         A new radar technique developed by a graduate student allows   
         imaging of the upper few feet of ice sheets on Earth and icy   
         worlds. The technique uses instruments on airplanes or satellites   
         to survey large regions quickly. The upper few feet of ice sheets   
         are important for measuring melt on Earth or looking for habitable   
         environments on icy worlds.   
      
         Previous airborne or satellite techniques could not image this   
         narrow region in detail.   
      
      
         Facebook Twitter Pinterest LinkedIN Email   
      
   ==========================================================================   
   FULL STORY   
   ==========================================================================   
   Scientists at the University of Texas Institute for Geophysics (UTIG) have   
   developed a radar technique that lets them image hidden features within   
   the upper few feet of ice sheets. The researchers behind the technique   
   said that it can be used to investigate melting glaciers on Earth as well   
   as detect potentially habitable environments on Jupiter's moon Europa.   
      
   The near-surface layers of ice sheets are difficult to study with airborne   
   or satellite ice-penetrating radar because much of what's scientifically   
   important happens too close to the surface to be accurately imaged. That   
   has left scientists relying on ground instruments that give only limited   
   coverage, or extracting ice cores -- a difficult and time-consuming   
   operation currently impossible to do on other planets.   
      
   The new radar technique combines two different radar bandwidths and   
   looks for discrepancies as a way of boosting the resolution. Because   
   the instruments are carried on airplanes or satellites, scientists can   
   quickly survey vast regions of ice.   
      
   To test the new technique, the team flew radar surveys over the Devon   
   Ice Cap in the Canadian Arctic where they mapped a slab-like layer of   
   impermeable ice near the surface. Further analysis suggested that the   
   ice layer is redirecting surface melt from the ice cap's snow-packed   
   surface into water channels downhill. The research was published May,   
   2023, in the journal The Cryosphere.   
      
   According to Kristian Chan, a graduate student at the UT Jackson School   
   of Geosciences who devised the technique, the study's findings about   
   the ice slab layer could help scientists predict the future of the ice   
   cap and its contribution to sea level rise.   
      
   "If you have only relatively thin ice layers then the firn [snow-packed   
   surface layers] has the ability to absorb and retain surface meltwater,"   
   Chan said.   
      
   "But if these impermeable slabs are widespread then the contribution of   
   surface melt to sea level rise is enhanced."  Surface melt is normal on   
   ice sheets during summer months. As the top of the previous winter's   
   snow warms up, meltwater sinks in and refreezes deeper in the snow,   
   forming thin ice layers.   
      
   Most of the ice layers on Devon Ice Cap, however, are much thicker   
   than expected, some forming slabs as much as 16 feet thick over several   
   miles. That makes them very effective at redirecting meltwater, which   
   the researchers confirmed when they matched the location of the thickest   
   ice slabs with that of meltwater rivers.   
      
   Chan said the findings demonstrate what scientists can accomplish with   
   the new technique.   
      
   "We used an airborne radar to find ice slabs on Devon Ice Cap, but   
   the same thing applies for detecting layers with an orbiting radar at   
   ice-covered 'ocean' worlds like Jupiter's moon Europa," he said.   
      
   Chan is part of a UTIG group, led by Senior Research Scientist Don   
   Blankenship, that is developing a radar instrument called REASON, which   
   will launch aboard NASA's Europa Clipper in 2024. Along with a European   
   Space Agency spacecraft that launched this year, scientists will soon have   
   two ice-penetrating radar instruments investigating Jupiter's moons Europa   
   and Ganymede. Both radar systems are compatible with Chan's technique.   
      
   With the new technique, scientists will be able to peer into the upper few   
   feet of the icy shells where they might find frozen brine, cryovolcanic   
   remnants or even plume fallout deposits. All are either potential   
   habitats or clues about habitable environments in the subsurface, said   
   coauthor Cyril Grima, a UTIG research associate who is also part of the   
   REASON team.   
      
   "Kristian has given us the ability to see things in this hidden part   
   just beneath the surface that is potentially accessible to future   
   landers," Grima said. "It's really improved the reconnaissance ability   
   of those radars."  The research was supported by the NASA Texas Space   
   Grant Consortium at UTIG, and the G. Unger Vetlesen Foundation. UTIG is   
   a research unit of the UT Jackson School of Geosciences.   
      
       * RELATED_TOPICS   
             o Space_&_Time   
                   # Moon # Jupiter # Uranus # Space_Probes   
             o Earth_&_Climate   
                   # Global_Warming # Snow_and_Avalanches # Ice_Ages #   
                   Climate   
       * RELATED_TERMS   
             o Ice_age o Ice_sheet o Antarctic_ice_sheet o Solar_system o   
             Meteor o Glacier o Phoenix_(spacecraft) o Larsen_Ice_Shelf   
      
   ==========================================================================   
      
    Print   
      
    Email   
      
    Share   
   ==========================================================================   
   ****** 1 ****** ***** 2 ***** **** 3 ****   
   *** 4 *** ** 5 ** Breaking this hour   
   ==========================================================================   
       * Salinity_Changes_Threatening_Marine_Ecosystems *   
       Plastic_Pollution_On_Reefs_Mostly_from_Fishing   
       * Detailed_Map_of_the_Heart *   
       Microplastics_Contamination_in_Lakes_and_...   
      
       * Diverse_Organic_Material_On_Mars *   
       How_the_Immune_System_Can_Alter_Our_Behavior *   
       Ocean's_Color_Is_Changing_Due_to_Climate_Change *   
       Start_of_Anthropocene_Epoch:_Canadian_Lake_...   
      
       * Pump_Powers_Soft_Robots,_Makes_Cocktails *   
       Rat_Poison_--_Neurotoxicant_--_In_Birds_of_Prey   
      
   Trending Topics this week   
   ==========================================================================   
   PLANTS_&_ANIMALS Biology Nature Food EARTH_&_CLIMATE Global_Warming   
   Environmental_Policy Environmental_Awareness FOSSILS_&_RUINS Fossils   
   Ancient_Civilizations Cultures   
      
      
   ==========================================================================   
      
   Strange & Offbeat   
   ==========================================================================   
   PLANTS_&_ANIMALS Tiny_Fish_Surprise_Scientists_in_'Volunteer's_Dilemma'   
   Capturing_the_Immense_Potential_of_Microscopic_DNA_for_Data_Storage   
   Bees_Make_Decisions_Better_and_Faster_Than_We_Do,_for_the_Things_That_Matter_to   
   Them EARTH_&_CLIMATE   
   Why_There_Are_No_Kangaroos_in_Bali_(and_No_Tigers_in_Australia)   
   Turning_Old_Maps_Into_3D_Digital_Models_of_Lost_Neighborhoods   
   Squash_Bugs_Are_Attracted_to_and_Eat_Each_Other's_Poop_to_Stock_Their   
   Microbiome FOSSILS_&_RUINS   
   Giant_Stone_Artefacts_Found_on_Rare_Ice_Age_Site_in_Kent,_UK   
   Fossils_Reveal_How_Ancient_Birds_Molted_Their_Feathers_--_Which_Could_Help   
   Explain_Why_Ancestors_of_Modern_Birds_Survived_When_All_the_Other_Dinosaurs   
   Died Apex_Predator_of_the_Cambrian_Likely_Sought_Soft_Over_Crunchy_Prey   
   Story Source: Materials provided by University_of_Texas_at_Austin. Note:   
   Content may be edited for style and length.   
      
      
   ==========================================================================   
   Journal Reference:   
      1. Kristian Chan, Cyril Grima, Anja Rutishauser, Duncan A. Young, Riley   
         Culberg, Donald D. Blankenship. Spatial characterization of   
         near-surface structure and meltwater runoff conditions across   
         the Devon Ice Cap from dual-frequency radar reflectivity. The   
         Cryosphere, 2023; 17 (5): 1839 DOI: 10.5194/tc-17-1839-2023   
   ==========================================================================   
      
   Link to news story:   
   https://www.sciencedaily.com/releases/2023/07/230712124607.htm   
      
   --- up 1 year, 19 weeks, 2 days, 10 hours, 50 minutes   
    * Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)   
   SEEN-BY: 15/0 106/201 114/705 123/120 153/7715 218/700 226/30 227/114   
   SEEN-BY: 229/110 112 113 307 317 400 426 428 470 664 700 291/111 292/854   
   SEEN-BY: 298/25 305/3 317/3 320/219 396/45 5075/35   
   PATH: 317/3 229/426