Drumlin Drumlin A drumlin, from the Irish word "droimnín" ("littlest ridge"), first recorded in 1833, and in the classical sense is an elongated hill in the shape of an inverted spoon or half-buried egg formed by glacial ice acting on underlying unconsolidated till or ground moraine. Drumlins occur in various shapes and sizes, including symmetrical (about the long axis), spindle, parabolic forms, together with transverse asymmetrical forms; their long axis is parallel to the direction of movement of the formative flow at the time of formation. Drumlins are typically long, less than high and between wide. Drumlins generally have a length:width
Blue ice (glacial) Zealand in January 2011. Blue ice is exposed in areas of the Antarctic where there is no net addition or subtraction of snow. That is, any snow that falls in that area is counteracted by sublimation or other losses. These areas have been used as runways (e.g. Wilkins Runway, Novolazarevskaya, Patriot Hills Base Camp) due to their hard surface, which is suitable for aircraft fitted with wheels rather than skis. Blue ice (glacial) Blue ice occurs when snow falls on a glacier, is compressed, and becomes part of the glacier. Air bubbles are squeezed out and ice crystals enlarge, making