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.
Ice sheets are important because they are at sea level, where climate change shows up. Melting ice sheets can be an early warning sign of global warming. We need to know what's happening to the ice because it is a major component of the Earth's climate system; it affects the climate and is effected by it.