Chinese surnames are used by Han Chinese and Sinicized ethnic groups in Mainland China, Hong Kong, Macau, Malaysia, Taiwan, Korea, Singapore, Vietnam and among overseas Chinese communities. In ancient times two types of surnames existed, namely xing (Chinese: å§; pinyin: xÃ¬ng) or lineage names, and shi (Chinese: æ°; pinyin: shÃ¬) or clan names.
An ice sheet is a large permanent layer of ice covering a continental shelf, defined as having an extent greater than 50,000 km2 (19,305 mi2). An ice sheet is larger than a glacier or ice shelf.
There are two ice sheets in the world today: the Antarctic ice sheet (which contains 61% of fresh water on the planet) and the Greenland ice sheet (containing 7%). Only about 32% of the world's fresh water is found in streams, lakes, and aquifers â the rest can be found in the ice sheets.