Given a sufficient period of time, the Earth is much more malleable than we generally give it credit for. We tend to think of changes to our planet as happening in geological time periods (“geologically speaking, that land mass formed extremely quickly…” and such) but not everything moves that slowly. In fact, some features move quite rapidly and change at a pace that is observable through rather conventional means, like satellite imagery.
This set of images spans from 1984 to 2012, and makes it very clear that a river can change its path not only over the course of 28 years, but in just a few months when given the right conditions. Rivers, of course, are one of the most unpredictable and rapidly changing parts of the planet given how they are affected not just by slow-moving forces, like erosion, but also near-instantaneous ones, like flooding and upstream snow melts, which can causes banks to expand and shift from their current course. That could be the case here, as the river pictured is in eastern Bolivia and would likely be getting significant runoff from the Andes.
What’s fascinating in this series of shots is not just that the rivers move, but also how they move. The primary action we see is the expansion of the river’s curves — the bends seem to be growing each year. That may be because of specific forces in that area or something happening upstream to increase waterflow, but it’s quite apparent. And then from 2007 to 2008 we see two sections of the river actually merge, forming a loop and what must be a small pool in the river.
This isn’t the first time we’ve covered satellite imagery in time-lapse form. Last time it was this striking series of images taken by the LandSat satellites which showed the staggering growth of Las Vegas over the course of 38 years.
Google Maps does not currently allow us to see historic satellite imagery, but it’s clear that they team has access to less-than-current images. Hopefully in the future more out of date (but still quite pertinent) image sets will be available and we’ll be able to observe and better understand the changes that are happening to our planet.