Assertion: glacier's velocity | /r/HasProperty | determined by the geometry of the ice
Facets:
value: melted over several years
type: TEMPORAL
Source sentences:
text: The velocity and motion in glaciers and ice sheets is determined by the geometry of the ice (ice thickness, surface slope) and by its physical properties (temperature, impurities, density), by the valley shape or lack of valley walls in the case of ice sheets, by the conditions at the glacier bed (frozen versus thawed bed, hard bedrock versus soft deformable substrate, type of subglacial drainage system), by the amount of ice that is floating in adjacent water (lake, sea or ocean) as a floating tongue or an ice shelf, and by the average accumulation and ablation rates (the surface mass balance, or net amount of snow received and melted over several years).