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.
Icebergs are edges of glaciers that have broken off and slipped into the ocean. Glaciers form on land by snow building up over thousands of years. Each layer of snow compresses those below until, 60 to 70 metres down, glacial ice forms. Glaciers then flow or creep towards the ocean under their own weight, and eventually slip in.