Geology – BLDGBLOG

Star Forts, Mines, and Other Maastricht Subterranea

I was in Maastricht, Netherlands, for a couple nights last week, mostly as a way to break-up my trip across the Atlantic and thus help get over jet-lag before attending an archaeology conference (where I currently type this).

I went specifically to Maastricht, however, because it’s home to an astonishing number of subterranean sites, from 800-year-old limestone mines and 17th-century star fortifications to NATO defense bunkers. I basically checked into my hotel then disappeared underground for the rest of the visit.

Here are some pics.

My morning started here, at the entrance to the Casemates Waldeck, a labyrinth of defensive earthworks complete with tunnels, counter-mine tunnels, barracks, and firing positions. Large parts of the system were then later repurposed as civilian air-raid shelters during WWII.

The geometric logic of the forts was—among other things—to lure enemy attackers in over cliff-like artificial drops and ridges, thinking they were on their way to the heart of the city. However, this simply trapped them between huge brick walls, directly in front of disguised gun emplacements, many of which were deliberately aimed at stomach-height to maximize suffering.

If you go through the door seen in the above photographs, meanwhile, you end up inside a bewildering system of multi-level tunnels weaving around for kilometers beneath the outer edge of the city.

Because the city has expanded and grown over the centuries, whole neighborhoods now sit atop these structures; if you live in Maastricht, you might very well have disused military fortification tunnels running under your basement.

What’s more, not all of the tunnels are mapped—which means that some are neither maintained nor stabilized. Apparently, seasonal floods have led to sinkholes above, as streets partially collapse into the system.

And that’s just one of many, many underground sites you can tour.

The next place I headed was called the Zonneberg Caves—which are not natural caves, but a colossal limestone mine—and I honestly can say I would spend entire weeks down there.

I’m just randomly typing facts from memory, because I’m on a break from a conference and want to get these photos up, which means I will almost certainly get a few details wrong, but I believe they said that “only” 80 or so kilometers of these ancient limestone mines remain from more than 200, and that the first shafts were cut in the 13th century.

The mines extend all the way over the international border into Belgium. The Belgian tunnels are apparently closed to the public, yet people sneak into them all the time.

There are 20th-century artworks painted on the walls, much older graffiti etched directly into rock, and massive corridors extending off on all sides into darkness.

If you’re into the underground and ever have an opportunity to spend more time than a tour down there, I would recommend it without any hesitation—and I will be deeply, deeply jealous.

The site is even complete with a little church altar.

Bear in mind, this is all still the same day.

The next site I went to was accessed through a locked metal door in the rock (pictured above). This system, known as the North Caves, is actually physically connected to the Zonneberg Caves, although it would take an hour or more to get between them underground. Like I say, I would go back there and wander around in a heartbeat.

The added interest of this latter system is that parts of it were used during WWII to house paintings by the Old Masters, protecting them from Nazi plunder and stray Allied bombs alike.

At the end, you go into a place called “the Vault” to see where Rembrandts and other paintings were hung while war waged above.

Finally, after many hours underground, I walked outside—and the first thing I saw was this rainbow. A cheesily enjoyable end to a fantastic day.

If you’re tempted to see any of these places yourself, and you hope to do so legally, check out Maastricht Underground for potential tours.

[All photos by Geoff Manaugh/BLDGBLOG.]

Mineral Hurricane

I recently had the pleasure of attending a press preview of the new documentary Architecton, directed by Victor Kossakovsky and released last week by A24.

Surreally, the screening I attended was held inside a Cedars-Sinai medical-imaging center in west Los Angeles. Seeing this particular film, with its intensely granular focus on the geological underpinnings of the built environment, amidst diagnostic tools designed for peering inside the human body seemed strangely appropriate.

I imagine that, if you were simply to wander into a room where Architecton was playing, it would very likely appear to be a film about geology: about rocks and mountains, quarries and mines, and the raw streams of matter that create and emerge from them.

There is an extraordinary early sequence, for example, from which the stills in this post were taken, where Kossakovsky captures a landslide. We watch as increasingly large rocks, from sand to gravel to room-sized blocks to immense boulders, all flow downhill in slow motion, crashing into one another, exploding, ricocheting, and splitting apart.

It looks for all the world like an oceanic phenomenon—a series of waves, not a solid planet at all, as if the Earth has begun to boil and heave with liquefaction.

The sequence then fades into what I believe is an aerial drone shot of the same landslide, but the visuals here become almost astronomical in their power and beauty, as if Architecton had somehow captured a proto-planetary storm of partially aerosolized rock. It looks like you’ve woken up inside the asteroid belt—or perhaps what J.M.W. Turner would have depicted if he had traveled in space. Not landscapes but nebulae.

There is something so elemental, even infernal, in this sequence, verging on the cosmic: glimpsing how the Earth itself was assembled through a billion-year maelstrom of mineral hurricanes, spherical landslides, and weather systems made entirely of geology.

Later, the camera lingers over detonations in the walls of strip mines. We watch rocks being bounced and agitated on conveyor belts, wet with leachate and acid. At one point, the camera stares into a minimalist doorway, cut like an Etruscan tomb, through which rocks tumble to be processed as abyssal red embers glow.

It’s just a mine, of course, but Kassakovksy has made it look like an alchemical complex, a brutalist oven in which all things planetary can be melted and enhanced, sluiced off and purified, distilled into a purely economic form. It is brute oceanic metallurgy.

It’s these early sequences that I could have watched literally for hours. It was also these scenes that felt so perfect for the unlikely setting in which the film was being screened that day, knowing that, as we all sat there, people in the rooms around me were getting CT scans, MRIs, and X-rays.

But the movie takes a more architectural turn here, increasingly focused on buildings and cities, on archaeological sites and ruins. We see residential towers in Ukraine, for example, ripped open by Russian missiles and drone-bombs, and then earthquake-damaged apartments undergoing demolition and clearance, followed by landfill-dumping operations so large they look like attempts at terraforming.

These are intercut with the film’s only speaking sections, where we watch architect Michele De Lucchi supervise the construction of a small rock circle in his garden. A light snow falls and hazy mountains are visible in the background. The scenes are meditative and calming.

At one point, De Lucchi’s circle is visually rhymed with an all-too-brief aerial glimpse of what I believe is the Richat Structure in Mauritania, continuing the film’s play on form and organization, as if rocks have within them a natural capacity to resemble storms and hurricanes—as if everything we believe to be is solid is, in fact, made of vortices and waves.

And this is all perfectly enjoyable; I was mesmerized.

But the film ends on a strange note. Despite appearing—to me—to be a documentary about the Earth, geology, and elemental form—about the human relationship with matter and our attempts to control it—Architecton concludes with a somewhat head-spinning turn in which the director himself appears on screen and asks De Lucchi, in person, why humans now construct such ugly buildings.

The question felt totally out of the blue to me and, frankly, irrelevant to the rest of the documentary. Either I had mis-understood everything I’d seen leading up to that point or perhaps Kassakovksy had felt pressured to deliver some sort of easy takeaway, an interpretation or rhetorical question that critics could discuss after viewing.

Speaking only for myself, what I wanted to discuss as I walked out of the cinema was not whether we should build fewer glass towers in Milan, but whether or not we understand what the Earth really is; whether landslide dynamics repeat, in miniature, the formational mechanics of rocky planets in the early solar system; or whether our cultural—and, yes, architectural—encounters with rock, especially in the form of mines and quarries, might force us to reevaluate how we define humanism in the first place. Some people think literature makes us human, but what if it’s actually metallurgy?

In the end, it was as if someone had created a 100-minute-long Rorschach test, composed of extraordinarily beautiful imagery of landslides and rocks, only to spring out from behind a screen and tell us that, this whole time, he had been thinking about classical architecture.

Nevertheless, the film is worth checking out—and I’d recommend doing so in a theater while you can, for the sheer scale of what Kassakovksy depicts.

(Thank you to A24 for providing the stills that appear in this post.)

geo/acc

Slag heap debris on the English coast has apparently been fusing into a new kind of sedimentary rock.

A team of geologists studying the beach recently “found a series of outcrops made from an unfamiliar type of sedimentary rock. The beach used to be sandy, so the rock must have been a recent addition. It was clearly clastic, meaning it was composed of fragments of other rocks and minerals (clasts) that have been cemented together in layers. On closer inspection, they found that the clasts were derived from the slag heap.” Based on inclusions of trash amongst the sediments, such as a discarded coin, some of this rock could not have been more than 36 years old.

It’s accelerated geology, part of what the researchers describe in their resulting paper as “a rapid anthropoclastic rock cycle,” one where a new class of geological material is “forming over decadal time scales rather than thousands to millions of years.”

These new coasts are likely forming elsewhere in the world, New Scientist adds: “Slag waste is a global phenomenon, and it is probably being turned to rock anywhere it comes into contact with ocean waves.” Let’s go find and map some more! The anthro-littoral, or geology itself as an archaeological artifact.

Crusted scablands of industrial coral, bulbous and pockmarked, herniate into the sea, long after the creatures who forged those materials have gone.

Institute for Controlled Speleogenesis

Recently, I’ve been looking back at a collaborative project with John Becker of WROT Studio.

The “Institute for Controlled Speleogenesis” (2014) was a fictional design project we originally set in the vast limestone province of Australia’s Nullarbor Plain.

[Image: A rock-acid drip-irrigation hub for the “Institute for Controlled Speleogenesis,” a collaboration between BLDGBLOG and WROT Studio; all images in this post are by John Becker of WROT Studio.]

The Nullarbor Plain is a nearly treeless region, roughly the size of Nebraska. It is also the world’s largest karst landscape, and thus home to hundreds of natural caves.

“There is a great variety of cave types under the Nullarbor,” as Australian Geographic explains, “but the plain’s most interesting features are long, deep systems (such the Old Homestead Cave), which are found only here, in the U.S. state of Florida, and on Mexico’s Yucatan Peninsula, all of which all have similar karst limestone layers.”

The Institute for Controlled Speleogenesis was imagined as a remote, thinly staffed site for applied geological research, where huge artificial caves could be generated below the Earth’s surface using a special acid mix—as safe as vinegar, but, importantly for our project, capable of dissolving limestone on a greatly accelerated timescale.

Subterranean spaces of every conceivable size, from tiny hollows and capillaries to vast megastructures, could thus be acid-etched into even the deepest karst formations, both rapidly and over decadal expanses of time.

The resulting rooms, tunnels, and interconnected cave systems could be used for a wide range of purposes: generating speleo-pharmaceuticals, for example, as well as testing recreational caving equipment, experimenting with underground agricultural systems, or developing new technologies for subterranean navigation, communication, inhabitation, and mapping.

As John writes on his own website—where you can also see larger, more-detailed versions of these images—our “aberrant caverns,” in John’s phrase, would be monitored in real-time by autonomous systems operating 24 hours a day.

The ever-growing caves could thus be left on their own, unsupervised, while the acid-drip system gradually etches down, drop by drop, reaching increasingly remote underground realms that the acid itself creates.

As a preliminary step, different blends of rock-acid mix would first be tested on large pillars aboveground, to choose or highlight specific spatial effects.

Controlled showers of rock-acid would result in totem-like sculptures, like industrial-scale menhirs—Stone Age ritual artifacts by way of 21st-century geochemistry.

Once the desired effects have been achieved, fields of bladders, nozzles, and injection arrays can be programmed and choreographed to enlarge an artificial cave mouth.

The irrigation system can then be continued underground. Necklaces of acid-drip arrays can easily be extended underground in order to expand the cave itself, but also to lengthen certain tunnels or to experiment with architecturally stable cave formations.

As John explains, the images seen here depict an “injection array using a pressurized system to move large quantities of solution to underlying areas of the cave network. These injection sites are outwardly the tell for a hidden world below. Much like oil derricks extracting resources from the earth, their density and scale across the landscape give you a glimpse into areas afforded the most resources for injection.”

Our initial siting of this in the Nullarbor Plain was motivated entirely by geology, but other large limestone provinces—from Kentucky or northern Arizona to southern France, and from California’s Lucerne Valley to Egypt—would also be good hosts.

While we looked into standard mining acids, currently used for stripping tailings piles of valuable minerals, it quickly became apparent that specific kinds of acetic acid—again, no more toxic than vinegar—offered a more viable approach for creating a maximally spacious site with minimally polluting environmental implications. (Of course, should someone without such qualms want to explore this set-up with no concern for its ecological impact, then much stronger acids capable of dissolving much stronger rocks could also be explored.)

In 2022, I was excited to see that John returned to this project, generating a new series of images using AI image-generation software trained on our earlier project documentation. Given their provenance, the resulting images are unsurprisingly cinematic—equal parts cyberpunk dereliction and underworldly luminescence.

Over the years, John has become a wizard at producing Modernist geological imagery, publishing images on his Instagram account—rock sculpted as smooth as paper and as diaphanous as a veil or curtain.

Check out his own website for more images of the Institute for Controlled Speleogenesis and other recent projects. And, if you like this, don’t miss “Architecture-by-Bee and Other Animal Printheads,” an earlier project of ours that I’m proud to say was published in Paul Dobraszczyk’s excellent recent book, Animal Architecture: Beasts, Buildings and Us.

(All images in this post are by John Becker of WROT Studio. This post contains a Bookshop.org affiliate link, meaning that I might receive a small percentage of any resulting sales.)

Cleared For Approach

[Image: “Forest and Sun” (1926) by Max Ernst.]

When I first saw this painting—“Forest and Sun” (1926) by Max Ernst, a composition and theme he continually revisited and changed over the course of his career—I mistook the tiny white squiggles in the lower right for a procession of human congregants or religious pilgrims, people approaching a huge, alien landform out of some strange act of homage or scientific curiosity. Alas, it’s just Max Ernst’s signature.

Whatever you’re approaching in 2023, may it be unfamiliar, potentially threatening, and new.

Potsdamer Sea

[Image: From Kiessling’s Grosser Verkehrs-Plan von Berlin (1920).]

It’s funny to be back in Berlin, a city where I once thought I’d spend the rest of my life, first arriving here as a backpacker in 1998 and temporarily moving in with a woman 14 years older than me, who practiced Kabbalah and had twin dogs and who, when seeing that I had bought myself a portable typewriter because I was going through a William Burroughs phase, blessed it one night in her apartment near the synagogue in a ceremony with some sort of bronze sword. It’s almost literally unbelievable how long ago that was. More years have passed since I spent time in Berlin—supposedly to study German for grad school, but in reality organized entirely around going to Tresor—than I had been alive at the time.

Because I’m here again on a reporting trip, I was speaking yesterday evening with a former geophysicist who, when the Berlin Wall came down, found work doing site-remediation studies and heritage-mapping projects on land beneath the old path of the Wall. He was tasked with looking for environmental damage and unexploded ordnance, but also for older foundations and lost buildings, earlier versions of Berlin that might pose a structural threat to the city’s future or that needed to be recorded for cultural posterity.

Ironically, in a phase of my life I rarely think about, I wrote my graduate thesis on almost exactly this topic, focused specifically on Potsdamer Platz—once divided by the Wall—and the role of architectural drawings in communicating historical context. When I was first here, in 1998 into early 1999, Potsdamer Platz was still a titanic hole in the ground, an abyss flooded with groundwater, melted snow, and rain, a kind of maelström you could walk over on pedestrian bridges, where engineering firms were busy stabilizing the earth for what would become today’s corporate office parks.

As I told the former geophysicist last night, I remember hearing at the time that there were people down there, SCUBA diving in the floodwaters, performing geotechnical studies or welding rebar or looking for WWII bombs, I had no idea, but, whatever it was, their very existence took on an outsized imaginative role in my experience of the city. Berlin, destroyed by war, divided by architecture, where people SCUBA dive through an artificial sea at its broken center. It felt like a mandala, a cosmic diagram, with this inverted Mt. Meru at its heart, not an infinite mountain but a bottomless pit.

What was so interesting to me about Berlin at the time was that it felt like a triple-exposure photograph, the city’s future overlaid atop everything else in a Piranesian haze of unbuilt architecture, whole neighborhoods yet to be constructed, everything still possible, out of focus somehow. It was incoherent in an exhilaratingly literal sense. In Potsdamer Platz, what you thought was the surface of the Earth was actually a bridge; you were not standing on the Earth at all, or at least not on earth. It was the Anthropocene in miniature, a kind of masquerade, architecture pretending to be geology.

The more that was built, however, the more Berlin seemed to lose this inchoate appeal. The only people with the power to control the rebuilding process seemed to be automobile consortiums and international hotel groups, office-strategy consultants not wizards and ghosts or backpacking writers. Perhaps the city still feels like that to other people now—unfinished, splintered, jagged in a temporal sense, excitingly so, a city with its future still taking shape in the waves of an underground sea—but it seems to me that Berlin’s blur has been misfocused.

In any case, with the caveat that I am in Berlin this week for a very specific research project, so many people I’ve met have pointed to the fall of the Wall as an explosive moment for geophysical surveys in the East. Engineers were hired by the dozen to map, scan, and survey damaged ground left behind by a collapsed imperialist Empire, and the residues of history, its chemical spills and lost foundations, its military bunkers and archaeological remains, needed to be recorded. The ground itself was a subject of study, an historical medium. On top of that, new freeways were being built and expanded, heading east into Poland—and this, too, required geophysical surveys. The future of the region was, briefly, accessible only after looking down. The gateway to the future was terrestrial, a question of gravel and sand, forgotten basements and fallen walls.

The SCUBA divers of the Potsdamer Sea now feel like mascots of that time, dream figures submerged in the waves of a future their work enabled, swimming through historical murk with limited visibility and, air tanks draining, limited time. Their pit was soon filled, the hole annihilated, and the surface of the Earth—which was actually architecture—returned with amnesia.

Terrestrial Astronomy

[Image: “The Empty Quarter (Nevada)” (2021), collage by Geoff Manaugh, using maps from the U.S. Geological Survey.]

I’m thrilled to have some map collages in the latest issue of the Yale Review.

[Image: “Groundwater Grids (North Dakota)” (2020), collage by Geoff Manaugh, using maps from the U.S. Geological Survey.]

I started making these during lockdown, as part of a larger (and, to be honest, now doomed-feeling) graphic novel project using public domain U.S. Geological Survey maps as the main material.

[Images: “Keys II (Florida)” (2020) and “Keys I (Florida)” (2020), collages by Geoff Manaugh, using maps from the U.S. Geological Survey; the source maps for these are particularly interesting, because they utilize satellite photography.]

The images in this post include a few collages not published in the Yale Review, but click through for the full issue’s broad selection of poetry, essays, fiction, and more.

[Images: “Morse Landscape II (Louisiana)” and “Morse Landscape I (Louisiana)” (2021), collages by Geoff Manaugh, using maps from the U.S. Geological Survey.]

And huge, huge thanks to Eugenia Bell for the editorial interest!

[Images: Various collages by Geoff Manaugh, using maps from the U.S. Geological Survey.]

If you’re looking for someone to design a book cover or album cover or event poster, hit me up.

[Image: “Terrestrial Astronomy (Nevada)” (2021), collage by Geoff Manaugh, using maps from the U.S. Geological Survey; it’s a pedestrian observation, but inverting the color scheme of geological maps makes them look like maps of stars.]

Cetacean Surroundsound

I was thinking about this whale song bunker idea the other week after reading about the potential for whale song to be used as a form of deep-sea seismic sensing. That original project—with no actual connection to the following news story—proposed using a derelict submarine surveillance station on the coast of Scotland as a site for eavesdropping on the songs of whales.

[Image: An otherwise unrelated image of whales, courtesy Public Domain Review.]

In a paper published in Science last month, researchers found that “fin whale songs can also be used as a seismic source for determining crustal structure. Fin whale vocalizations can be as loud as large ships and occur at frequencies useful for traveling through the ocean floor. These properties allow fin whale songs to be used for mapping out the density of ocean crust, a vital part of exploring the seafloor.”

The team noticed not only that these whale songs could be picked up on deep-sea seismometers, but that “the song recordings also contain signals reflected and refracted from crustal interfaces beneath the stations.” It could be a comic book: marine geologists teaming up with animal familiars to map undiscovered faults through tectonic sound recordings of the sea.

There’s something incredibly beautiful about the prospect of fin whales swimming around together through the darkness of the sea, following geological structures, perhaps clued in to emerging tectonic features—giant, immersive ambient soundscapes—playfully enjoying the distorted reflections of each other’s songs as they echo back off buried mineral forms in the mud below.

I’m reminded of seemingly prescient lyrics from Coil’s song “The Sea Priestess”: “I was woken three times in the night / and asked to watch whales listen for earthquakes in the sea / I had never seen such a strange sight before.”

Someday, perhaps, long after the pandemic has passed, we’ll gather together in derelict bunkers on the ocean shore to tune into the sounds of whales mapping submerged faults, a cross-species geological survey in which songs serve as seismic media.

Planetary Supercinema

[Image: Courtesy Capella Space.]

The Geocinema group is hosting a six-week class this spring called Signals and Storms, a kind of planetary-scale media studies workshop. Participants will research and critique what they describe as an emerging super-system of always-on recording technologies, from “geosensors” and street-level surveillance cameras up to weather satellites—tools that suggest a future possible medium for “largely distributed infrastructures of filmmaking.”

The image above, meanwhile, comes courtesy of Capella Space and depicts a new satellite design—as of January 2020—that allows the company to produce “on-demand observations of anywhere on Earth” (what they have elsewhere called “persistent monitoring from space”).

These sorts of technologies—though currently out of reach for the typical budgets of a film studio, let alone an arts group—are part of an increasingly omnipresent media-production infrastructure, one that continuously records the surface of the Earth in real time and in great detail, or where Geocinema gets its name in the first place.

The Magnetic Depths

The emerging sub-genre of public service announcements about geological surveys—apparently offered not just due to FAA regulations, but to quell the growth of potential conspiracy theories—continues with this heads-up about a “low-flying airplane” over parts of Virginia and North Carolina.

[Image: USGS map of eastern Virginia, altered by BLDGBLOG.]

Of course, beyond the idea of simply preempting the development of new conspiracy theories, the work being done by the project is fascinating in and of itself: “Instruments on the airplane will measure variations in the Earth’s magnetic field and natural low-level radiation created by different rock types near and up to several miles beneath the surface. This information will help researchers develop geologic maps of the area that will be used to better understand sand resources and underground faults in the region.”

While we’re on the topic of the Virginia/North Carolina border region, I’m reminded of why there’s a strange “notch” in the state line, a story “that mostly involves collecting taxes and avoiding swamps”: “The rough and rowdy inhabitants living close to the border told North Carolina tax collectors they lived in Virginia, [Gates County historian Linda Hofler] said. When the Virginia tax man came, they said North Carolina was their home.”

In any case, check out the USGS for more on the low-flying geomagnetic airplane and The Virginian-Pilot for more on VA/NC border history.

Geomedia, or What Lies Below

[Image: Courtesy USGS.]

I love the fact that the U.S. Geological Survey had to put out a press release explaining what some people in rural Wisconsin might see in the first few weeks of January: a government helicopter flying “in a grid pattern relatively low to the ground, hundreds of feet above the surface. A sensor that resembles a large hula-hoop will be towed beneath the helicopter,” the USGS explains—but it’s not some conspiratorial super-tool, silently flipping the results of voting machines. It’s simply measuring “tiny electromagnetic signals that can be used to map features below Earth’s surface,” including “shallow bedrock and glacial sediments” in the region.

Of course, the fictional possibilities are nevertheless intriguing: government geologists looking for something buried in the agricultural muds of eastern Wisconsin, part Michael Crichton, part Stephen King; or CIA contractors, masquerading as geologists, mapping unexplained radio signals emanating from a grid of points somewhere inland from Lake Michigan; or a rogue team of federal archaeologists searching for some Lovecraftian ruin, a lost city scraped down to its foundations by the last Ice Age, etc. etc.

In any case, the use of remote-sensing tools such as these—scanning the Earth to reveal electromagnetic, gravitational, and chemical signatures indicative of mineral deposits or, as it happens, architectural ruins—is the subject of a Graham Foundation grant I received earlier this autumn. That’s a project I will be exploring and updating over the next 10 months, combining lifelong obsessions with archaeology and ruins (specifically, in this case, the art history of how we depict destroyed works of architecture) with an interest in geophysical prospecting tools borrowed from the extraction industry.

In other words, the same remote-sensing tools that allow geological prospecting crews to locate subterranean mineral deposits are increasingly being used by archaeologists today to map underground architectural ruins. Empty fields mask otherwise invisible cities. How will these technologies change the way we define and represent architectural history?

[Image: Collage, Geoff Manaugh, for “Invisible Cities: Architecture’s Geophysical Turn,” Graham Foundation 2020/2021; based on “Forum Romano, Rome, Italy,” photochrom print, courtesy U.S. Library of Congress.]

For now, I’ll just note another recent USGS press release, this one touting the agency’s year-end “Mineral Resources Program Highlights.”

Included in the tally is the “Earth MRI” initiative—which, despite the apt medical-imaging metaphor, actually stands for the “Earth Mapping Resource Initiative.” From the USGS: “When learning more about ancient rocks buried deep beneath the surface of the Earth, it may seem surprising to use futuristic technologies flown hundreds of feet in the air, but that has been central to the USGS Earth Mapping Resource Initiative.”

[Image: A geophysical survey of northwestern Arkansas, courtesy USGS.]

What lies below, whether it is mineral or architectural, is becoming accessible to surface view through advanced technical means. These new tools often reveal that, beneath even the most featureless landscapes, immensely interesting forms and structures can be hidden. Ostensibly boring mud plains can hide the eroded roots of ancient mountain chains, just as endless fields of wheat or barley can stand atop forgotten towns or lost cities without any hint of the walls and streets beneath.

The surface of the Earth is an intermediary—it is media—between us and what it disguises.