Eyes on Earth Episode 2 - Chernobyl
When an accident occurred at the Chernobyl Nuclear Power Plant's No. 4 reactor in Ukraine on April 26, 1986, Landsat satellites were among the first to capture visual evidence of its widespread impact. This episode of Eyes on Earth outlines how the disaster focused the world's attention on the value of remote sensing.
YOUNG: Hello everyone, welcome to this episode of Eyes on Earth, a new podcast that focuses on our ever changing planet and the people here at EROS and across the world who use remote sensing to monitor and study the health and well-being of earth. I'm your host, Steve Young. Today's guest is John Dwyer, Chief of the Science and Applications Branch here at EROS, which is also known as the Earth Resources Observation and Science Center. We are located right out of Sioux Falls, South Dakota and we are talking today about the EROS connection to the explosion of the Chernobyl Power Plant in the Ukraine on April 26, 1986. Welcome, John.
DWYER: Hi Steve, thank you for having me.
YOUNG: So back in 1986, Landsat 5 is orbiting the planet. At what point after the reactor explodes did we realize that Landsat had acquired an image of the burning reactor?
DWYER: This was kind of an interesting situation because at the time we were doing support for another federal agency looking to monitor vegetation conditions around the world, especially in agricultural regions and the Soviet Union was always kind of a target of interest, understand what was going to be their status of their crops, wheat and that kind of thing. Well, we happened to have one of their personnel on site and I think he received a phone call about it, that they had through other means, knowledge that this may have happened. And obviously, that initiated a chain of inquiry. It was like well, ok, could we have acquired any imagery over the area? When would be the next time we could? etc...
YOUNG: Landsat 5 then just happened to be going over at a good time?
DWYER: It was a bit serendipitous, yes.
YOUNG: When we found out that we did in fact have an image from Landsat 5, did it get exciting out here at EROS?
DWYER: Yes, the pace picked up quite a bit with things. Yes, like I said, I can't remember, I wasn't involved in all aspects of it, but we did have an acquisition real close if not just shortly after that and we were able to get the data sent to us. Back then, I was a senior data analyst. Myself and others were responsible getting it into our systems, looking at it, and of course, you know the first instinct is to look at the thermal data because that is where you're gonna see heat signatures, but it was quickly evident that the pixels were saturated because of the intensity of the phenomenon. And then looking at other band combinations, when we started looking at the short wave infrared, the physics drives some of this because as the temperature rate increases the peak emissivity shifts to shorter wave lengths. So what we thought we detect in the thermal, we then picked up in the short wave infrared and because those bands were 30 meters as opposed to the 120 meter thermal data, it started to be a fairly sharp discrimination. And, so we could actually see the exact pixel or two that, from the reactor complex that were effected. The other thing that we were able to do is that adjacent to the power generating facility was the cooling ponds. And so under normal operations you'd see warmer water flow out from the complex, circulate and then cooler water come in. So we did look at some pre-incident images and so you could see that circulation pattern and then shortly after that where the water is at uniform temperature, which is a clear indication that operations were shut down. So you have the number of aspects as a convergence of evidence so to speak, you know, with actually not having boots on the ground so to speak.
YOUNG: We determined that we have this image and it is here at EROS, did that 15 minutes of fame come to roost here in EROS? Did people start hearing about this place and wonder what's going on?
DWYER: Well, it did and obviously inquiries were coming in probably from other federal agencies as well as the news media in terms of, ok, we hear you guys operate these things called Landsat, you guys have imagery, what can you see and that kind of stuff. Our Center Director at the time, Al Watkins, was really handling all of that, you know, communication with other agencies and the media but it did result in a CBS news truck coming out one night for a live interview and feed. And they interviewed Al, they brought their camera crew into the data analysis lab. I showed the images on the monitors and they filmed that. That was our claim to fame. And it probably was an incident that really did bring satellite remote sensing a little bit more into the public front. I mean it had never been hidden but it wasn't something the average person was aware of. I mean today, imagery from google earth whether it be satellite or aircraft or whatever is ubiquitous, right? But, keep in mind 1986, personal computers were just coming online so.
YOUNG: You are perhaps known by friends, colleagues and the community as somebody who worked at EROS. When Al Watkins is on CBS talking about what we have here at EROS, does that filter down to you and the way people react to you in the community after that happened?
DWYER: I did have a funny incident. I was a member of the YMCA and a couple days after that I was walking in and there was a tv room there in the men's locker room. People were watching the news. I guess they must have seen the news clip at some point. At that point all eyes kind of followed me as I walked through. One person sheepishly asked, do you work at EROS and what do you guys do out there? So, I mean it was funny but you know I told them we don't do classified work.
YOUNG: So it sounds like this is a fairly significant validation of an important event in global history this image we had. Does the EROS archive include other significant images through time? If so, Can you give us some examples?
DWYER: Oh, I'm sure it does. The first Gulf War is an example when the Iraqi's were burning the Kuwait oil fields. Where we captured that big time. Stark imagery you could see not only the smoke from the flames, but over time the residue that lands on the soil, you know from the hydrocarbon. Theres a number of things like that. The value of the Landsat archive is that the effort to continuously comprehensively image the earth's land masses enables us to look at changes over time. Looking at imagery over the Aral Sea for example, we can see how drawdown in the lake due to water consumption exposes soils in that area. A lot of those salts and things have some health issues associated with them. Wild fires, that has become a ubiquitous tool for mapping wild fires every year. The extent of damage from flooding, hurricanes, tsunamis, alot of that. Landsat is always called on to look at response to natural and human disasters. And that is what Landsat satellites were designed to do. Basically a global monitoring tool.
YOUNG: We've been talking to John Dwyer, the Science & Applications Branch Chief at EROS about the center's role in helping to validate the Chernobyl Nucleaur Power Plant explosion back in 1986. It's been a very interesting conversation John, thank you.
DWYER: Thank you, Steve.
YOUNG: We hope you come back for the next episode of Eyes on Earth. This is a podcast that is a product of the US Geological Survey Department of the Interior. Thanks for joining us.