A combination of technologies has enabled scientists to confirm what they have long believed about the San Andreas fault: the land around the fault in California has been rising and sinking on a large scale, building up energy that will release when the next, inevitable earthquake along the San Andreas fault occurs.
Published in Nature, the research details the “vertical fingerprint” of the earthquake cycle that has long known to be “locked and loaded,” according to geologists. Until now, “vertical motions arising from tectonic sources have remained enigmatic,” as they write. But data recorded by the EarthScope Plate Boundary Observatory’s GPS array researchers from the University of Hawai’i at Manoa, University of Washington and Scripps Institution of Oceanography (SIO) has shown that various land on either side of the San Andreas fault — where the Pacific and North American tectonic plates meet — has been rising and sinking (known as “uplift and subsidence”) a few millimeters each year.
Horizontal motions have been easier to track, historically. Vertical motions present a new chapter of insight into how earthquakes occur.
Various research has been done to try to estimate what the effect of the pending San Andreas event will be; last year, the United Stated Geological Survey said there is a 7% chance of a magnitude 8 earthquake happening in the next 30 years. But each year, new research sheds light on deeper uncertainty as to when and how powerful the earthquake will occur and be. There is one thing scientists agree on: the event is inevitable and will create much devastation. Until it occurs, technology enables us to gain insight into how the land is moving, and in which directions.