have magnetic rocks alternating positive and negative away from the ridges peak here's the mid-atlantic bridge coming down through here almost perfectly symmetric on either side about are these white and black stripes these are often called zebra stripes geologists no the earth is like a giant magnet with the north and a south pole more but the magnetic poles on fixed every three hundred thousand years or so the magnetic field suddenly flips 180 degrees well when the field flips a compass that was previously pointing north will swing to the south this reversing a fierce magnetic field is a very interesting and exciting but very puzzling phenomenon for geophysicist to explain the ribbon scientists think this reversal explains the stripes either side of the ocean ridge up in the 1960s geologist discovered that Malton volcanic rock known as magma swelled up deep underground to create the images from the atlanta Pacific on as magma wells up between the tectonic plates it pushes the seafloor bomb forms the colossal mid-ocean ridge thousands of feet high when the rock is hot and Malton its magnetic minerals line up with the north-south direction of the Earth's magnetic field as the magma cools the minerals are locked in position way these rocks act as a permanent record in the magnetic poles location when the rocks were formed as more and more magma is forced up the old crust is pushed away from the ridge and records the reversals in the earth's magnetic polarity you have reversals a magnetic polarity and the C four acts sort of like a tape recorder and records these changes in magnetization then the pattern I've magnetic stripes allows people to calculate the speed at which the plates are moving apart the new zebra stripes are proof that overtime the sea floor in both the Atlantic and the Pacific is spreading away from the region's at a rate more than two inches a year the Montreal urges needed proof that magma created the ridge the NIF red hot molten rock is forming the enormous mountain range in the pacific the surrounding water should be warm in 1977 a team of scientists set out to discover whether this warm water really existed in Dudley foster was the pilot for these historic dives it's been an exciting occupation because we're on the cutting edge science a new discoveries all-time little every cruisers a new group assignments with scientific objectives and miss the exploration and the discovery that's really what puts the thrill in the job that'll for weeks the crew scanned the undersea mountains without success 1 and then they hit the jackpot no wait a bizarre killer abroad spewing hot toxic gas called we saw the water source share Marie soar like a bubbling in a glass teapot or something it we stock the temperature probe in there and measured 38 39 degrees Fahrenheit which was really amazing because that the oceans a huge he said so to see something warm like that was car starter in