What factor contributed to the placement of the border between north and south korea?

How do oceanographers measure the salinity of ocean water?

When volcanoes erupt, magma (hot, molten rock) rises toward the surface of the earth. as magma cools, solid rock forms. this rock contains substances from the interior of the earth. which of the following natural resources is likely to be plentiful near subduction zones where volcanic activity has occurred in the past?

What is the relationship between groundwater and aquifers?