Narration:

Transcript:

DOUGLAS: This is a site that's a kilometer long and half a kilometer wide, and it was constructed on a coral reef flat, and it has a 100 really complex stone structures made of basalt, something called columnar basalt. The whole island, including the site, is just is covered with some of the densest vegetation on Earth actually. It's one of the wettest places on Earth. There's a really great variety of vegetation. There are vines there that grow a few feet every day. We just couldn't believe the complexity of what we were seeing, and nobody knew it was there because the dynasty that built Nan Madol collapsed 4 or 500 years ago, and without constant maintenance of vegetative clearance, the vegetation just covered everything. We got a NASA grant to utilize airborne lidar to scan the rest of the island, which is probably 100 times larger than just Nan Madol and the close environs that we did before. And then we found that the whole island was covered was the landscape that radically transformed. And again, nobody, nobody knew. This is not going to be feasible in many places on Earth. So what about--what about satellite lidar? The ICESat-2 data, you know, if you analyze the data properly, it's really giving you this very precise elevations for water, for sea level.

JACOB: We're looking into using ICESat-2 for that shallow water bathymetry because a lot of the, you know, the coastal environment on Pohnpei is really interesting to us. In areas where the vegetation isn't so bad, I think there's a lot of promise, especially for like monitoring archaeological--like the state of not just archeological sites, but other things. Just like monitoring the kind of the structural integrity of stuff. For example, we just like tested out in the Sacred Valley of Peru, where is another place where we work. You can see some of these terraces that, you know, people are still using. I mean, it shows up beautifully in these ICESat-2 transects because they don't have vegetation on them.

DOUGLAS: The application of this ICESat-2 data to monitoring sea level at some of these islands. People know that sea level rise is going to endanger these islands. And I'm thinking about the human impact. I'm also thinking about the cultural impact of losing that culture diversity. You have thousands of these islands that are occupied by these very different groups, and each of them has developed a really interesting and special culture, and if we lose that, what are we actually losing? Think about that.