Glaical+Glossary

El Nino effect: a periodic 'blip' in the usual global climatic characteristics caused by a short-term reduction in the intensity of the cold ocean current that normally exists off the west coasts of South America. It results in unusual patterns of temperature and rainfall and can lead to droughts and floods in certain parts of the world Glacial period: a period of ice advance associated with falling temperatures Interglacial: a period of ice retreat assoicated with rising temperatures Ice sheet: a large body of ice over 50,000km squared in extent Ice cap: a smaller body of ice (less than 50,000km squared) usually found in mountainous regions Glacier: a finger of ice usually extending downhill from an ice cap and occupying a valley Accumulation: inputs to the glacier budget, such as snowfall and avalanches Ablation: outputs from the glacier budget, such as melting Snout: the front of the glacier Glacier budget: the balance betwen the inputs (accumulation) and the outputs (ablation) of a glacier Abrasion: a process of erosion involving the wearing awya of the valley floor and sides (glaciers) and the shoreline (coastal zones) Plucking: a process of glacial erosion where individual rocks are plucked from the valley floor or sides as water freezes them to the glacier Rotational slip: slippage of ice along a curved surface Moraine: sediment carried and deposited by the ice Buldozing: the pushing of deposited sediment at the snout of by the glacier as it advances Hummock: a small areas of raised ground rather like a large molehill Corrie: a deep depression on a hillside with a steep back wall, often containing a lake Arete: a knife-edged ridge, often formed between two corries Pyramidal peak: a sharp-edge mountain peak Glacial trough: a wide, steep-sided valley eroded by a glacier Truncated spur: an eroded interlocking spur characterised by having a very steep cliff Hanging valley: a tributary glacial trough perched up on the side of a main valley, often marked by a waterfall Ribbon lake: a long narrow lake in the bottom of a glacial trough Lateral moraine: a ridge of frost-shattered sediment runningalong the edge of a glacier where it meets the valley side Medial moraine: a ridge of sediment running down the centre of a glacier formed when two lateral moraines merge Terminal moraine: a high ridge running accross the valley representing the maximum advance of a glacier Drumlin: an egg-shaped hill found on the floor of a glacial trough Responsible tourism: the idea of encouraging a balance between the demands of tourism and the need to protect the environment Sustainable management: a form of management that ensures that developments are longlasting and non-harmful to the environment Fragile environment: an environment that is easily damaged unbalanced and damaged by natural or human factors Avalanche: a rapid downhill movement of a mass of snow, ice and rocks, usually in a mountainous environment Loose snow avalanche: a powdery avalanche originating from a single point Slab avalanche: a large-scale avalanche formed when a slab of ice and snow breaks away from the main ice pack