Mid ocean ridges question?

Question

How does lava cool?

What is the mid-ocean ridge?

What device is used to map the ocean floor?

Who was Harry Hess? What is it notable for?

How to mid ocean ridges form?

Answer 1

Lava cools either by air or water.  It cools quickly because even the temperature of the hottest day is still colder than 2100 degrees.

The Mid-ocean ridge is a mountain range in the water formed by seafloor spreading.

Sonar, sonar is Sound Originating Naval Onbord Radar, and is used to bounce radar signals off the ocean floor so satellites can receive the signals to make maps.

Harry Hess was a Navy Captain who was also a professor in Princeton University who was known for the discovery of seafloor spreading. http://pubs.usgs.gov/gip/dynamic/HHH.htm... read his biography it is very interesting.

The Mid-Ocean Ridges form by seafloor spreading, which happen only at divergent plate boundaries.  as the plates slide further apart and replaced by new lava (rock) form outward ridges in the middle of the ocean.