海底扩张

seafloor spreading (geology)

surname Hai

ocean / sea / CL:個|个[ge4],片[pian4] / great number of people or things / (dialect) numerous

seabed / seafloor / bottom of the ocean

(equivalent to 的 as possessive particle)

background / bottom / base / end (of the month, year etc) / remnants / (math.) radix / base

to enlarge

expansion / dilation / to expand (e.g. one's power or influence) / to broaden

surname Zhang

to open up / to spread / sheet of paper / classifier for flat objects, sheet / classifier for votes

theory of seafloor spreading (geology)