Walker Lane Redux

It’s been an interesting few days here in Southern California, with several large earthquakes and an ensuing aftershock sequence out in the desert near Ridgecrest. Ridgecrest, of course, is at the very southern edge of the Walker Lane—more properly part of the Eastern California Shear Zone—a region of the country that runs broadly northwest along the California/Nevada state border and that I covered at length for the May 2019 issue of Wired.

[Image: My own loose sketch of the Walker Lane, using Google Maps].

To make a story short, a handful of geologists have speculated, at least since the late 1980s, that the San Andreas Fault could actually be dying out over time—that the San Andreas is jammed up in a place called the “Big Bend,” near the town of Frazier Park, and that it is thus losing its capacity for large earthquakes.

As a result, all of that unreleased seismic strain has to go somewhere, and there is growing evidence—paleoseismic data, LiDAR surveys, GPS geodesy—that the pent-up strain has been migrating deep inland, looking for a new place to break.

That new route—bypassing the San Andreas Fault altogether—is the Walker Lane (and its southern continuation into the Mojave Desert, known as the Eastern California Shear Zone).

What this might mean—and one of the reasons I’m so fascinated by this idea—is that a new continental margin could be forming in the Eastern Sierra, near the California/Nevada state border, a future line of breakage between the Pacific and North American tectonic plates.

If this is true, the Pacific Ocean will someday flood north from the Gulf of California all the way past Reno—but, importantly, this will happen over the course of many millions of years (not due to one catastrophic earthquake). This means that no humans alive today—in fact, I would guess, no humans at all—will see the final result. If human civilization as we know it is roughly 15,000 years old, then civilization could rise and fall nearly 700 times before we even get to 10 million years, let alone 15 million or 20.

In any case, these recent big quakes out near Ridgecrest do not require that the most extreme Walker Lane scenario be true—that is, they do not require that the Walker Lane is an incipient continental margin. However, they do offer compelling and timely evidence that the Walker Lane region is, at the very least, more seismically active than its residents might want to believe.

I could go on at great length about all this, but, instead, I just want to point out one cool thing: the far northern route of the Walker Lane remains something of a mystery. If you’ve read the Wired piece, you’ll know that, for the Walker Lane to become a future continental edge, it must eventually rip back through California and southeastern Oregon to reach the sea. However, the route it might take—basically, from Pyramid Lake to the Pacific—is unclear, to say the least.

One place that came up several times while I was researching my Wired article was the northern California town of Susanville. Susanville is apparently a promising place for study, as geologists might find emergent faults there that could reveal the future path of the Walker Lane.

If you draw a straight line from the Reno/Pyramid Lake region through Susanville and keep going, you’ll soon hit a town called Fall River Mills. Interestingly, following the long aftershock sequence of these Ridgecrest quakes, there was a small quake in Fall River Mills this morning.

While seeing patterns in randomness—let alone drawing magical straight lines across the landscape—is the origin of conspiracy theory and the bane of serious scientific thinking, it is, nevertheless, interesting to note that the apparently linear nature of the Walker Lane could very well continue through Fall River Mills.

[Image: The Ridgecrest quakes and their aftershocks seem to support the idea of a linear connection along the Walker Lane; note that I have added a straight orange line in the bottom image, purely to indicate the very broad location of the Walker Lane].

While we’re on the subject, it is also interesting to see that, if you continue that same line just a little bit further, connecting Pyramid Lake to Susanville to Fall River Mills, you will hit Mt. Shasta, an active volcano in northern California. Again, if you’ve read the Wired piece, you’ll know that volcanoes seem to have played an interesting role in the early formation of the San Andreas Fault millions of years ago.

In any case, in cautious summary, I should emphasize that I am just an armchair enthusiast for the Walker Lane scenario, not a geologist; although I wrote a feature article about the Walker Lane, I am by no means an expert and it would be irresponsible of me to suggest anything here as scientific fact. It does interest me, though, that aftershocks appear to be illuminating a pretty dead-linear path northwest up the Walker Lane, including into regions where its future route are not yet clear.

Insofar as the locations of these aftershocks can be taken as scientifically relevant—not just a seismic coincidence—the next few weeks could perhaps offer some intriguing suggestions for the Walker Lane’s next steps.

300 Years of Dust

I’m late to the news that the ancient Akkadian Empire might have collapsed due to “dust activity” that “persisted for 300 years.” As a resident of Los Angeles, it’s sobering to read.

“Archaeologists have long been baffled by the abrupt abandonment of northern Mesopotamian settlements roughly 4,200 years ago,” Eos reports. This otherwise mysterious abandonment might have been catalyzed by three centuries of dust—“dust for 300 years”—arising from extreme drought and aridity.

The dust was so bad, in fact, it left a geological record in regional stalactites.

Perhaps that’s how the end will come, as a slow but relentless accumulation of dust on windowsills—in California, Arizona, Nevada—a civilizational collapse that should have been signaled, in retrospect, by the rapid growth of the house-cleaning economy, but that, for at least a generation, will take the form of puzzled homeowners wiping wetted cloths along wood trim, wondering if there’s something going on outside.

Mass Effect

[Image: The weight of a human being; courtesy U.S. Library of Congress].

Over at the consistently interesting Anthropocene Review, a group of geologists and urbanists have teamed up to calculate the total mass of all technical objects—from handheld gadgetry to agricultural equipment, from domesticated forests to architectural megastructures—produced by contemporary humanity.

[Image: Courtesy U.S. Library of Congress].

Their seemingly impossible goal was to gauge “the scale and extent of the physical technosphere,” where they define the technosphere “as the summed material output of the contemporary human enterprise. It includes active urban, agricultural and marine components, used to sustain energy and material flow for current human life, and a growing residue layer, currently only in small part recycled back into the active component.”

The active technosphere is made up of buildings, roads, energy supply structures, all tools, machines and consumer goods that are currently in use or useable, together with farmlands and managed forests on land, the trawler scours and other excavations of the seafloor in the oceans, and so on. It is highly diverse in structure, with novel inanimate components including new minerals and materials, and a living part that includes crop plants and domesticated animals.

Their “preliminary” calculations of all this suggest a mass of 30 trillion tons.

[Image: Interior of Hughes Aircraft Company cargo building, courtesy U.S. Library of Congress].

The authors immediately put this number into a darkly awe-inspiring perspective:

If assessed on palaeontological criteria, technofossil diversity already exceeds known estimates of biological diversity as measured by richness, far exceeds recognized fossil diversity, and may exceed total biological diversity through Earth’s history. The rapid transformation of much of Earth’s surface mass into the technosphere and its myriad components underscores the novelty of the current planetary transformation.

This “rapid transformation of much of Earth’s surface mass into the technosphere” means that we are turning the planet into technical objects, dismantling and recombining matter on a planetary scale. The idea that the results of this ongoing experiment “may exceed total biological diversity through Earth’s history” is sobering, to say the least.

Read the rest of the article over at The Anthropocene Review.

(Originally spotted via Chris Rowan).

Mineral TV and the Archipelago of Abandoned Shopping Malls

“A mediaeval cathedral was a sort of permanent and unchangeable TV programme that was supposed to tell people everything indispensable for their everyday life, as well as for their eternal salvation.” So says Umberto Eco, speaking at the Bibliotheca Alexandrina, Egypt, 2003.

[Image: Cathedral at Bourges, by Arnaud Frich].

This makes me wonder if everyone on Earth could take everything they know and carve it into a cliffside somewhere – or a mountain – sculpting all that rock into a cathedral; and, then, if they could take that hulking monolith of information and minerals and break it off, launch it into orbit, send it drifting through space… It’d be a kind of moving table of contents for the human species. A knowledge-object.
Would that have a better chance than NASA’s so-called Golden Record, that got sent out with Voyager, of explaining the Earth and human history to distant civilizations?

[Image: NASA’s Golden Record, “intended to communicate a story of our world to extraterrestrials.” The record is really “a 12-inch gold-plated copper disk containing sounds and images selected to portray the diversity of life and culture on Earth,” including the sound of “surf, wind and thunder, birds, whales, and other animals,” and a signed letter from then-president Jimmy Carter. A Menudo video was reportedly removed at the last minute].

Or, instead of demolishing old buildings, perhaps we should detach them from the Earth’s surface and send them into space as lessons for alien species. Like that Michael Crichton novel. You could learn about the Earth by studying its architecture – because the planet flings buildings everywhere. Constantly.
Archipelagoes of abandoned shopping malls pulled slowly toward distant planets. There goes the Mall of America…
A new film directed by Jerry Bruckheimer.