I am fascinated by plate tectonics so this week I researched the Juan de Fuca plate. The Juan de Fuca plate along with the Cocos Plate and the Nazca Plate found in Central and South America are all remnants of a much larger plate known as Farallon Plate, which was subducted under the North American Plate except for these remnants. The Juan de Fuca plate is all oceanic crust and is about 300 miles long. What is especially neat about this small plate is that it has all three boundaries present not to mention, earthquakes and volcanoes! The Juan de Fuca plate is the smallest of all the plates and has actually broken into three pieces. The Juan de Fuca has two platelets, the Explorer plate to the North and the Gorda plate to the South. Geologists believe the Explorer Ridge separated from the Juan de Fuca plate around four million years ago and the Gorda Ridge broke apart much earlier. Fracture zones between the three pieces have become transform boundaries and produce numerous earthquakes daily although they have very small magnitudes so they are never really felt. (USGS)
About 200 miles from the coast of Washington state is the west side of the Juan de Fuca plate. It is a divergent ridgethat meets the Pacific plate. The center portion of the western plate is known as the Juan de Fuca Ridge with the Explorer ridge to the north and the Gorda ridge to the South. The Juan de Fuca Ridge is actually an underwater volcanic mountain range that is home to a large submarine volcano called the Axial Seamount, which was created by a hotspot. This enormous volcano measures two hundred meters or six hundred fifty feet in height and is four kilometers wide or about two and half miles, fifteen kilometers or nearly nine miles in length. It is significant because it is monitored constantly and has been predicted to erupt again by 2020. This volcano also has hydrothermal vent fields and it is believed to be home to the earliest forms of life on earth. While researching, I stumbled upon a website that actually offers a summer expedition to the ridge. Check it out! (http://www.divediscover.whoi.edu/expedition8/index.html)
The east side is a convergent boundary that is subducted by the North American Plate. The Explorer Ridge or northern platelet is no longer subducting. The subduction of the Juan de Fuca plate under the North American Plate in the Pacific Northwest has created at least fifteen (15) volcanic mountains know as the Cascade Range Volcanoes. The Cascade Range starts in northern California and extends north to British Columbia, Canada. Some of the earliest volcanoes collapsed into calderas as they erupted forming beautiful lakes, hot springs and geysers. Crater Lake, created due to the eruption of Mount Mazama, is the deepest lake in the United States, at one thousand, nine hundred and thirty–two (1,932) feet, is known for its crystal clear water and very blue color. The USGS reports that there is still a lot of seismic activity in the Cascade Range and the Juan de Fuca plate is subducting about four centimeters each year. Forecast: Watch out something big just might happen soon! There is extensive information on the Juan de Fuca plate. I just “touched the tip of the iceberg” on this little plate.