PhotoSat: The spy satellites that came in from the Cold War

photosat

The spy satellites that came in from the Cold War

Gerry Mitchell, president and founder of PhotoSat, tells Martin Ashcroft how photographic images taken by U.S. spy satellites in the 1960s can help the mining industry determine the safety of tailings deposits.

Safety is the No1 priority on every mining company’s list of values, and after a series of tragic events over the last few years, mine tailings have risen to the top of the safety agenda. Tailings dams are the most common disposal system for mining waste, and have been employed for over a hundred years to enable large scale and long-term storage of waste from the mineral extraction process. It is an unfortunate and poignant irony that the company we now know as Vale was once called Companhia Vale do Rio Doce, which translates roughly into English as Valley of the Sweet River. Sadly, the sweetness of the Rio Doce, downstream of the Samarco Mineração iron ore mine in Brazil’s Minas Gerais province, was soured on 5 November 2015 after the collapse of the Fundão dam, killing 19 people and spilling millions of gallons of mineral waste into the countryside the dams were designed to protect. The repercussions of this event have reverberated far and wide over the intervening years, not least in the investor community, where a number of influential shareholders launched class action lawsuits. Samarco, jointly owned by Vale and BHP, claimed the dams had been regularly inspected and declared to be safe. Investors began to wonder who they could trust.

A little over three years after the Fundão dam disaster, on 25 January 2019, a tailings dam at the Córrego do Feijão iron ore mine near Brumadinho in Minas Gerais, the same Brazilian state as the Samarco dam, suffered a catastrophic failure, killing over 250 people, many of whom were Vale employees eating lunch in the canteen, downstream of the dam.

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Vale S.A. Source: www.b1technicalinvestigation.com

Investors now began to wonder how they could obtain independent verification of the safety of mine tailings deposits. Just two days after the tragic event, a group of investors led by the Church of England Pensions Board and the Council of Ethics of the Swedish National Pension Funds called upon 727 mining companies to make disclosures about their tailings storage facilities for an independent

“After the Brumadinho disaster there was a huge international reaction, including the Church of England and the Swedish Government Pension Fund, who demanded that mining companies get their act together. The first thing they asked for was a complete inventory of all tailings dams and what the consequence of failure of them would be. A lot of companies have been scrabbling to figure that out”

photosat The spy satellites that came in from the Cold War

global database, the Global Tailings Portal. The Investor Mining & Tailings Safety Initiative was subsequently formed and a global review was announced, coconvened by the International Council of Mining and Metals (ICMM), the Principles for Responsible Investment (PRI) and the United Nations Environment Programme (UNEP), to establish an international standard on tailings storage facilities. “After the Brumadinho disaster there was a huge international reaction,” says Gerry Mitchell, president and founder of PhotoSat, “including the Church of England and the Swedish Government Pension Fund, who demanded that mining companies get their act together. The first thing they asked for was a complete inventory of all tailings dams and what the consequence of failure of them would be. A lot of companies have been scrabbling to figure that out.” Helping to figure that out is the latest line of business for PhotoSat, which can use satellite images to make astonishingly accurate calculations of the contents of a dam. Mine tailings dams are often huge structures, some of which were built over fifty years ago and added to over time. Many of them do not have accurate engineering records of how they were originally constructed and subsequently developed and extended. Without those initial designs, working out the volume of tailings contained in such a structure can only be guesswork. If only you had some detailed photographs of the site over the course of its development.

Location of the Mufulira, Zambia mine site and tailings dam.

NOTE - Reproduced from the Ordnance Survey Map with the c Crown copyright licence number 100024244 Savills (UK) Ltd NOTE - Published for the purposes of identification only and permission of the Controller of H.M. Stationery Office. although believed to be correct its accuracy is not guaranteed.

Inactive tailings deposit

Mufulira tailings dam deposition since 1987

c Image copywrite Maxar

“To measure the volume of tailings in dams that have no initial engineering information, we can use the US spy satellite data to get the original topography before the tailings dams were built”

Vancouver-based PhotoSat was founded in 1993 by Gerry Mitchell after a career as a seismic specialist with oil giant BP. The company specializes in elevation surveying for civil engineering infrastructure projects and the planning and design of resource development projects for clients in mining, oil and gas, engineering and environmental companies and government agencies. PhotoSat’s team of geophysicists, engineers and associated geoscientists has delivered over 1000 survey projects, and has developed a new technology to

Soviet Long-Range Aviation Airfield 1963

photosat The spy satellites that came in from the Cold War

c Smithsonian National Air and Space Museum

US Keyhole spy satellite photo showing two regiments of Tupelov bombers at the Dolan, Kazakhstan, Soviet nuclear bomber airfield during the Cold War. U.S. Air Force Archives.

produce the world’s most accurate satellite survey data, with better than 20cm elevation accuracy. “We provided a lot of information for the two engineering investigations of the Brazilian dam failures,” says Mitchell. “Initially our contracts were with New York law firms who were working for the engineering companies, or Vale itself.” This information was based on contemporary images, of course, but nobody could give a complete picture without historical data. Then Mitchell remembered using cold war spy satellite images in a civil engineering project in Sudan almost 20 years ago. “We started looking at the 1960s American spy satellite data (from the US Keyhole Spy Satellite Program) that was declassified by President Clinton in 1995,” he says. “It’s stereo satellite photo data. I first got into it when I did a job in Sudan about 18 years ago for a Canadian oil company.” At the time, he explained, the original owners had been accused of depopulating the oil basin of Sudan. The accusers claimed there had been two million people there. Mitchell’s company was engaged to determine how many people had been there in the 1960s and 70s. “It wasn’t possible to tell from modern satellite data, but using this declassified American satellite data we were able to show that where there were now ten thousand people, in 1965 there were about ten huts. It was spectacular data.” Even more spectacular was the discovery that the US spy satellites had taken pictures of the whole world, not just Russian military installations. The US Geological Survey, which now hosts the collection of declassified images on its website, has incredibly high-resolution American spy satellite data that covers the entire DRC copper belt, for instance, as well as the tailings dams that collapsed in Brazil. This is exactly what PhotoSat needs to calculate the volume of tailings in a dam, and help satisfy the demands of the Investor Mining & Tailings Safety Initiative.

“We’re finding that almost everywhere we look we can see stereo data from the 60s from these American spy satellites,” says Mitchell. “It’s about one and a half to two metre resolution – and that was in the mid-sixties. We didn’t reach anything like that kind of resolution commercially until 2000. The first commercially available satellite photos from 1979 have probably 1/100th of that resolution. “As far as we can tell,” he continues, “this is the first example of this data being used for engineering applications.” PhotoSat does not have exclusive use of the US spy

Image: Freepik.com

Elevations Red = 1,270 m Blue = 1,210 m

4 km

Elevation surface of the current surface of the Mufulira tailings dam derived from a Maxar WorldView-3 satellite image collected on March 23, 2020.

satellite images, however. They are available for everyone, but what is exclusive is the technology PhotoSat has created to calculate the volume contained in a dam. “To measure the volume of tailings in dams that have no initial engineering information, we can use the US spy satellite data to get the original topography before the tailings dams were built,” explains Mitchell. “Then we can use the current highresolution satellite data, which is our main business (we survey mine sites all over the world to 15cm accuracy) using Maxar’s WorldView satellite data. When we combine them, we can measure the volume in these tailings deposits.” Armed with the images and the technology, PhotoSat’s current emphasis is on independently demonstrating the accuracy and effectiveness of the system, but not on one of the failed Brazilian dams, where the consequences of failure have already been demonstrated. Better to use a current dam and produce a calculation of its contents for international scrutiny. “We have spy satellite data over the two Brazilian dams,” says Mitchell, “but we haven’t published that because we thought it would be better to look at a successful dam rather than a dam break.” They chose instead a tailings dam at the Mufulira Mine in Zambia, part of the Mopani Copper Mines complex, where Glencore is the majority owner. “The Mufulira tailings dam looks like it was very well designed, very well maintained and is very well managed, as far as we can tell. One of the key features we’re looking at is in the history of the dam; how close did the water come to the embankment? In Mufulira it never came closer than about 200 metres. “Investors and insurers are saying ‘without independent verification, what can we believe?’ So one of our motivations is to be able to produce independently verifiable data that mine owners can use to demonstrate to insurers, investors and regulators how well their tailings dams have been built and maintained.” Conveniently, the Mufulira Dam was commissioned in 1989. “In addition to the satellite photos from 1967, there are 290 cloud free satellite photos from 1988

“We have spy satellite data over the two Brazilian dams,” says Mitchell, “but we haven’t published that because we thought it would be better to look at a successful dam rather than a dam break.”

photosat The spy satellites that came in from the Cold War

New tailings embankment

Pre 1967 tailings deposits

Image: Freepik.com

An illustration of the recovery maneuver used to capture the CORONA film-return bucket with the Keyhole camera film.

to the present,” says Mitchell. “Nobody asked us to do this, so this is a totally independent survey. Without talking to anyone involved, we are demonstrating how much information we can establish.” Altogether, there are 315 archived photos from various satellites over the years. “We can see how the dam was built, and where the tailings pond was throughout the history of the dam,” says Mitchell. “That’s significant because in the two Brazilian failures they let the tailings pond go right up to the embankments. That was a key factor in why the dam embankments were water saturated and ultimately failed. Upstream tailings dam embankments need unsaturated sand to be stable. If they’re water saturated, which the two Brazilian dams were, then they’re unstable.” After comparing the satellite images over the years, PhotoSat is able to produce an accurate cross section showing the elevation of the surface of the tailings pond at various stages of its development. Using this data, the company has calculated that the Mufulira dam currently contains 50 million cubic metres of tailings. In its response to the Church of England survey, Glencore had declared this to be 79 million cubic metres. It’s a significant difference. The initial questionnaire to the mining

“One of our motivations is to be able to produce independently verifiable data that mine owners can use to demonstrate to insurers, investors and regulators how well their tailings dams have been built and maintained”

companies asked what the consequences of a tailings dam failure would be. Noone can possibly be sure of that unless they know how much the dam contains, and the only way to make an accurate

2020

photosat The spy satellites that came in from the Cold War

The Mufulira tailings dam topographic surfaces for March 23, 2020 and September 22, 1967. Cross section showing the tailings dam topographic surfaces for different years.

1989

1,500 m

KH-4B CORONA Reconnaissance Satellite with the Keyhole camera.

volume measurement is to understand the starting surface. For the mines that have no engineering data relating to the construction of their tailings dams, this might never have been possible without the U.S. spy satellite photographs, Maxar’s current, high-resolution satellite imagery and PhotoSat’s unique system of processing the data. “The Global Tailings Review is recommending that every tailings deposit in the world be classified initially as having an extreme consequence of failure,” explains Mitchell, “until the board of directors signs off on a report which says the consequences of failure are less than extreme. To figure out the consequences you need to know the quantity of tailings and water that would potentially flow downstream in the event of a dam break.”

Thanks to the US Keyhole Spy Satellite Program over fifty years ago, combined with PhotoSat’s technology, the level of investor risk is now much easier to establish.