... 1950s researchers discovered long, ocean-girdling ridges. A ridge is a range of hills or hilly terrain, but the ocean ridges also contained a crack—a deep valley or rift. In the 1960s the researchers ... May 4, 2009. Some researchers believe a magnetic pole reversal may occur in the near future.Muller, Richard A. “Avalanches at the Core-Mantle Boundary.” Geo-physical Research Letters 29 (2002): ... peri-odic lava ows of land volcanoes. Decades before scientists discovered the mid-ocean system, some researchers, such as the French scientist Bernard Brunhes (1867–1910), had found evidence of magnetic...