THE HYDROLOGIC CYCLE MOVES WATER ACROSS THE BIOSPHERE
FIGURE 6.4 The hydrologic cycle includes two major subcycles, the oceanic and terrestrial subcycles, connected by the 40,000 km3 of precipitation of oceanic origin that falls on land and the 40,000 km3 of runoff that flows back to the oceans each year. (Differences in arrow width represent differences in amounts of water flux.)