An iceberg is a piece of freshwater ice more than 15 m long that has broken off a glacier or an ice shelf and is floating freely in open water. Smaller chunks of floating glacially derived ice are called "growlers" or "bergy bits". Much of an iceberg is below the water's surface, which led to the expression "tip of the iceberg" to illustrate a small part of a larger unseen issue. Icebergs are considered a serious maritime hazard.
An iceberg in the Arctic Ocean
Northern edge of Iceberg B-15A in the Ross Sea, Antarctica, 29 January 2001
Grotto in an iceberg, photographed during the British Antarctic Expedition of 1911–1913, 5 Jan 1911
Tabular iceberg, near Brown Bluff in the Antarctic Sound off Tabarin Peninsula
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include non-salty mineral-rich waters such as chalybeate springs. Fresh water may encompass frozen and meltwater in ice sheets, ice caps, glaciers, snowfields and icebergs, natural precipitations such as rainfall, snowfall, hail/sleet and graupel, and surface runoffs that form inland bodies of water such as wetlands, ponds, lakes, rivers, streams, as well as groundwater contained in aquifers, subterranean rivers and lakes. Fresh water is the water resource that is of the most and immediate use to humans.
Freshwater ecosystem
Image: Amazonas, Iquitos Leticia, Kolumbien (11472506936)
Image: Cove with Shamans Rock Olkhon Island Lake Baikal Russia (14594856552)
Image: Transition from Sawgrass to Coastal Habitat, NPS Photo (9250299462)
