Post by 1dave on Apr 23, 2019 6:41:02 GMT -5
Move Over, San Andreas: There’s an Ominous New Fault in Town
www.wired.com/story/walker-lane-move-over-san-andreas-fault/?mbid=email_onsiteshare
TWO Scenarios:
www.wired.com/story/walker-lane-move-over-san-andreas-fault/?mbid=email_onsiteshare
. . .
“Boy, the GPS data really revolutionized our thinking,” Faulds said. Almost overnight, plate tectonics was no longer something geodesists had to speculate about with fieldwork or maps; it had become something they could watch unfold in real time. GPS technology is now capable of recording millimeter-scale changes in the landscape, accurate enough to measure the growth rate of a human fingernail. The past 30 years' worth of data has been breathtaking enough, but in another few decades GPS geodesy is likely to reshape our entire understanding of Earth's crust. Every geodesist I spoke with described the field with a barely contained sense of awe and excitement.
Yet the discovery did not, as one might expect, trigger a surge of interest in the Walker Lane. Scott Bennett, of the US Geological Survey, told me that practically “99 percent of geologists” still consider the San Andreas to be the single most dominant plate boundary in the American West. In this sense, Faulds' idea makes him an outlier. But, Bennett added, just look at a map. The zone stretching away from the Salton Sea, where the San Andreas begins, up into the southern part of the Walker Lane has been quite seismically active of late. Something must be going on there.
. . .
As Faulds and I neared Pyramid Lake, he brought up the work of Tanya Atwater, widely considered a visionary in the field of plate tectonics. In the 1980s, Atwater began creating a series of animations depicting the birth and evolution of the San Andreas Fault. They suggest a precedent, Faulds said, for what is happening along the Walker Lane. Early on in the animations, it appears that the modern-day Baja Peninsula is destined to remain a part of the North American Plate; then, at about 7 million years ago, it abruptly cleaves away, creating the Gulf of California. This shift, Faulds said, was largely due to the presence of a chain of old volcanoes on the inland side of the San Andreas. They warmed and softened the continental crust, creating a line of weak spots like the perforations between two rows of postage stamps. That's where the land ripped apart.
An uncannily similar situation may be playing out today, Faulds told me. As you head north from the Gulf of California into the Mojave Desert, an area known as the Eastern California Shear Zone, you pass scores of beautiful old volcanic craters and lava tubes. These features, many of which have become popular hiking destinations, form a line of perforation all the way up the Eastern Sierra, right along the highway that brought me to Reno.
“Boy, the GPS data really revolutionized our thinking,” Faulds said. Almost overnight, plate tectonics was no longer something geodesists had to speculate about with fieldwork or maps; it had become something they could watch unfold in real time. GPS technology is now capable of recording millimeter-scale changes in the landscape, accurate enough to measure the growth rate of a human fingernail. The past 30 years' worth of data has been breathtaking enough, but in another few decades GPS geodesy is likely to reshape our entire understanding of Earth's crust. Every geodesist I spoke with described the field with a barely contained sense of awe and excitement.
Yet the discovery did not, as one might expect, trigger a surge of interest in the Walker Lane. Scott Bennett, of the US Geological Survey, told me that practically “99 percent of geologists” still consider the San Andreas to be the single most dominant plate boundary in the American West. In this sense, Faulds' idea makes him an outlier. But, Bennett added, just look at a map. The zone stretching away from the Salton Sea, where the San Andreas begins, up into the southern part of the Walker Lane has been quite seismically active of late. Something must be going on there.
. . .
As Faulds and I neared Pyramid Lake, he brought up the work of Tanya Atwater, widely considered a visionary in the field of plate tectonics. In the 1980s, Atwater began creating a series of animations depicting the birth and evolution of the San Andreas Fault. They suggest a precedent, Faulds said, for what is happening along the Walker Lane. Early on in the animations, it appears that the modern-day Baja Peninsula is destined to remain a part of the North American Plate; then, at about 7 million years ago, it abruptly cleaves away, creating the Gulf of California. This shift, Faulds said, was largely due to the presence of a chain of old volcanoes on the inland side of the San Andreas. They warmed and softened the continental crust, creating a line of weak spots like the perforations between two rows of postage stamps. That's where the land ripped apart.
An uncannily similar situation may be playing out today, Faulds told me. As you head north from the Gulf of California into the Mojave Desert, an area known as the Eastern California Shear Zone, you pass scores of beautiful old volcanic craters and lava tubes. These features, many of which have become popular hiking destinations, form a line of perforation all the way up the Eastern Sierra, right along the highway that brought me to Reno.
TWO Scenarios:
