With several earthquakes being shown at 10KM depth with alarming frequency, I decided to dig a little. I went to the USGS website and downloaded the earthquake data for the last 1 year. for depths between 8 & 12 Km's and magnitude between 2.5 to 7 on the Richter scale. I got 11324 results. When i apply ranges and keep 10 KM as a specific datapoint i get this most shocking result. This is not natural, and this many ? Are these all tactical nukes ?

Link - https://earthquake.usgs.gov/earthquakes/map/?extent=-89.50704,-270&extent=89.50096,630&range=search&timeZone=utc&settings=true&search=%7B%22name%22:%22Search%20Results%22,%22params%22:%7B%22starttime%22:%222020-04-15%2000:00:00%22,%22endtime%22:%222021-04-22%2023:59:59%22,%22minmagnitude%22:2.5,%22maxmagnitude%22:7,%22mindepth%22:8,%22maxdepth%22:12,%22orderby%22:%22time%22%7D%7D

In the 1970s, Los Alamos National Laboratory explored a science-fiction approach to tunneling: using nuclear power to literally melt holes through rock and turn the melted rock into tunnel lining. by Steve Weintz Digging out deep underground complexes or undersea bases could be expedited the Atomic way, in an alternate universe where the wildest ideas of the 1950s, 60s and 70s came to pass. Although our own timeline relies on mega-engineering for transportation, energy and architectural infrastructure, for the past half-century we've mostly relied on conventional power sources and design principles.

Today's Tunnel Boring Machines (TBMs) rank among the wonders of modern machinery. As wide as a several-story building and as long as a football field, these giant metal worms chew their way through rock and earth to dig out the world's ever-expanding networks of subways, drain tunnels, mines and bunkers. Aft of a huge rotating cutting head, a series of powerful jacks press, push and release the TBM along the tunnel's walls, to drive the excavation forward.

From the tunnel head forward of the cutting head, the excavated material trundles through the bulk of the machine like food through a gut to waiting hopper cars, which carry the rock out of the tunnel to a dump area. The insides of the TBM form a mass of engines and moving parts as dense as a sub's interior, full of noise and motion.

But in the 1970s, Los Alamos National Laboratory explored a science-fiction approach to tunneling: using nuclear power to literally melt holes through rock and turn the melted rock into tunnel lining. One product of the lab's research was a patent for a nuclear subterrene—a machine which could theoretically move through rock the way a submarine moves through water.

"The Atomic Subterrene," writes Mark, the author of the superlative Atomic Skies blog, "is a very atompunkish name. It sounds like a gadget Tom Swift might invent, and which would then be stolen by vaguely Slavic communists." But it grew out of serious Cold War propulsion research and aimed to solve serious problems in civil engineering. In an alternate timeline, it might have transformed America.

During the pursuit of nuclear-powered flying machines in the 1950s, Los Alamos engineers built an electrically-powered mockup of a prototype reactor that heated propellant to 3000 degrees centigrade. When the reactor project was canceled, team members sought other applications for their work. After reading Edgar Rice Burroughs' At The Earth's Core, an engineer named Bob Potter decided to see if the tungsten heating elements developed for the reactor mockup could melt rock.

Potter's 1961 experiments showed that indeed, the technology could punch through rock by melting it into lava. But the lab turned to other matters and Potter's concept laid fallow until a curious incident at a coffee shop in 1970 revived the idea.

Lab workers were shooting the breeze after a meal and the subject of Potter's rock melter came up. Someone suggested driving the device with a nuclear reactor, and while the notion was being discussed a Congressman stopped by to greet the Los Alamos men. Mistaking their blue-sky talk for an actual program, the Congressman enthusiastically endorsed the idea and would raise it with his oversight committee. Upon learning of the Congressman's plan, Norris Bradbury, Los Alamos' director, approved of the idea and made the informal discussion a real thing.

A study group was assembled and a bold paper was produced. The nuclear subterrene when fully developed would be “capable of penetrating the earth to depths of tens of kilometers... To extend geological and geophysical exploration into the earth's mantle.”

A cutting head with no moving parts, which worked by melting rather than cutting, need not be circular and its tunnels need not be cylindrical but could be square or any other shape. With no moving parts, there would be almost no vibration, a key advantage where ground disturbance was an issue.

American life could be transformed. As Mark writes,

"Aside from mining, excavating underground roads and pipes was an obvious use. Chemicals and gasses could be stored in underground chambers. Electrical energy could be stored in the form of underground pressurized air ‘batteries,’ compressed in during periods of excess production and used to drive turbines when more energy was needed. The subterrene could dig storage cavities for toxic and nuclear waste, too deep for them to ever trouble the surface. The heat and pressure found deep underground could be exploited for chemical processing. Cities, even farms, could be extended underground."

In 1972 the National Science Foundation funded a full-scale study of the nuclear subterrene. Small-scale electrically-powered prototype drills were built and one was used by the National Park Service to drill drainage holes at Bandelier National Monument near Los Alamos. The rock penetrator's lack of vibration was essential to preserving the archaeological site while the holes were drilled.

The study's full-scale concepts, however, remain its most memorable results. Both subterrene designs channeled the tremendous heat of nuclear reactions into heating elements in the nose. Two cutting-head designs were looked into, one for common rock and one for hard rock. One combined a traditional rotary cutting head with the cylindrical rock-melters, while the other replaced the rotary head with dozens of nuclear-powered needle probes. The probes would unevenly heat the rock face causing it to crack and crumble. In both designs, most of the broken rock would be sent down the subterrene's core to waiting hoppers for disposal, just like modern TBMs.

Unique among excavation equipment, however, was how the subterrenes would handle tunnel reinforcement. Both designs used nuclear heat to melt some of the excavated rock into volcanic glass and extrude it as a lining on the inside of the growing tunnel. The subterrene would generate its own reinforced cladding out of the waste rock as it proceeded.

It's possible news of the subterrene project reached Gene Roddenberry, the creator of Star Trek. A RAND study about underground transport appeared in 1972 and in 1973 Roddenberry's pilot for a new sci-fi TV series premiered. In Genesis II (which failed to become a series) a system of underground transport tunnels, much like Elon Musk's Hyperloop, features as a key background feature. The "nuclear drilling device" is mentioned as key to the system's development.

But besides a bit part in a TV pilot, the nuclear subterrene didn't get much farther. In 1975, the project was transferred from the NSF to the new Department of Energy and quietly disappeared. The concept resurfaced in the 1980s as a way of digging tunnels for bases on the Moon and other worlds but remained a concept. Advances in conventional excavation equipment since the 1970s make modern TBMs perform as well or better than Los Alamos' conceptual nukes.

These days the only place you'll find the subterrene discussed is that wild and wooly backcountry populated by those obsessed with aliens, conspiracies, magic technology and general crankiness. But like other daring ideas from the twentieth century, time may one day bring the nuclear subterrene back for review. The human need for holes will only grow.

Steve Weintz, a frequent contributor to many publications such as WarIsBoring, is a writer, filmmaker, artist, animator.

This has always been the most common depth, and if you were on the USGS site it says somewhere that estimating depth is hard, it's often off by a kilometer, and when they are in doubt they default to 10 km (which of course helps solidify 10 km as the most common depth. Where did this idea come from that there are tunnels this deep anyway? Why would anyone construct anything that deep, down in an unstable zone? How did these tunnel borers get deep enough in the first place to set off nuclear weapons without people noticing? When you think of all the crime that is done and gotten away with in ordinary basements, it seems pretty odd to try to go deeper than any known manmade shaft.

This idea of deep tunnels dug with bombs has intrigued me and I think it must have come from this cold war project. This article sums it all up quite well. tldr, we tried digging wide holes, we tried digging deep holes, we sent radioactivity all over the world, it's not a good idea (but if we could only direct a little tiny beam of antimatter we could dig a better hole...)

https://www.smithsonianmag.com/smart-news/the-us-once-wanted-to-use-nuclear-bombs-as-a-construction-tool-1957380/

The U.S. Once Wanted To Use Nuclear Bombs as a Construction Tool From digging a harbor to expanding the Panama Canal, how couldn’t nuclear bombs be used?

By Colin Schultz SMITHSONIANMAG.COM JANUARY 16, 2013 In 1962, the Atomic Energy Commission wanted to see how big of a hole they could make with a nuclear bomb. Enter, Project Sedan. The year was 1957. The Cold War was in full swing, and Sputnik was in the air. The U.S. was seemingly lagging behind in the technological arms race and needed to make a show, a display of power and prowess. Formed five months earlier by the U.S.’s Atomic Energy Commission, Project Plowshare, says Motherboard, was a project in which the nation’s scientists were supposed to find something useful to do with all the nuclear expertise they had acquired throughout World War II and its aftermath.

In what stands as the preeminent example of the high-stakes one-upmanship that fueled the Cold War, Sputnik’s launch put a ton of pressure on U.S. researchers to come up with a similar marquee scientific achievement. As historian Norman Chance explains, scientists at the Lawrence Radiation Laboratory suggested that using nuclear bombs as huge shovels would offer the “highest probability of early beneficial success” in the early stages of Plowshare. From 1961 through 1973, Project Plowshare saw 27 nuclear detonations. Many of these were at a test site in Nevada, says Motherboard, but some were a bit more experimental. In 1973, Project Rio Blanco, an operation under the banner of Project Plowshare,

“was an attempt to release 300 trillion cubic feet of natural gas under the Rocky Mountains by blasting apart caverns more than a mile deep with a trio of 33-kiloton bombs. It was the final of three attempts by Plowshare researchers to create what basically amounted to nuclear fracking.”

The project team wanted to blow a path for a railway line through California’s Bristol Mountains; they wanted to use nukes to expand the Panama Canal; and they wanted to use underwater explosions to carve out a harbor in Alaska. Plowshare’s first act was Project Gnome. In 1961, “the U.S. went ahead with Gnome, burying a 3.1 kiloton device over 1,100 feet deep in a massive salt deposit below New Mexico.” The goal was to see if underground nuclear explosions could be used to generated electricity. The result was to vent radioactive material to the atmosphere.

And, in the least productive but most destructive test, the scientists wanted “to see how big of a hole a nuclear bomb could make.” Motherboard: “It proved to be a really big hole.”

That test, Project Sedan, spewed radioactive fallout across four states, contaminating “more Americans than any other nuclear test.” Such a foolhardy project continued for so long, says Motherboard, in part because the public’s knowledge of the dangers of nuclear testing wasn’t quite keeping pace with the visions scientists had for the bombs’ uses. Eventually, though, the public caught on. In 1977, decades after it started and “amidst public uproar,” Project Plowshare was shut down.

About Colin SchultzColin Schultz Colin Schultz is a freelance science writer and editor based in Toronto, Canada. He blogs for Smart News and contributes to the American Geophysical Union. He has a B.Sc. in physical science and philosophy, and a M.A. in journalism.

I'm in the process of closing about a hundred tabs on my cell, and this is extremely low effort on my part, but I wanted to say Thanks. I appreciate skimming these kind of digs. One never knows when a small piece of knowledge will unlock something bigger. ?