60' Era of new instrumentation and international cooperation (1945-) Ah International Geophysical year Atlantic program Crao (1957-1959) 20 CuMYU The spatial coverage in an ocean requires the efforts and costs which cannot be A向放 LGY. covered by a nation. Rogram J957-1959 60T 0 20 0Era of new instrumentation and international cooperation (1945 - ) International Geophysical year Atlantic program (1957-1959) The spatial coverage in an ocean requires the efforts and costs which cannot be covered by a nation