WEBVTT 00:00:07.767 --> 00:00:10.860 I'm Kasey Cantwell and I work for NOAA's Office of Ocean Exploration and Research 00:00:11.060 --> 00:00:14.940 and I'm the expedition coordinator of the Okeanos Explorer Mountains in the Deep expedition. 00:00:18.619 --> 00:00:25.340 The overall goal of this expedition is to get a good first look at a number of the deep-sea habitats that exist throughout the Central Pacific Basin. 00:00:25.540 --> 00:00:27.870 Specifically, we've been focusing on seamounts. 00:00:36.165 --> 00:00:42.950 So the Central Pacific Basin is largely unknown and we understand so little about these seamounts that populate a large chunk of the seafloor. 00:00:43.150 --> 00:00:48.960 So when we've been moving the ship from American Samoa up to Honolulu, we took advantage of the opportunity to 00:00:49.160 --> 00:00:56.420 explore some very remote regions and to map and then conduct ROV dives on a number of seamounts that we have very little information about. 00:00:59.996 --> 00:01:03.060 We're exploring the Pacific Ocean seamounts because they're so largely unknown. 00:01:03.582 --> 00:01:05.690 We don't even know what they look like in a lot of cases. 00:01:06.617 --> 00:01:08.200 When we come out and we first start looking in this area, 00:01:08.400 --> 00:01:14.430 we're looking at very coarse-resolution maps of the seafloor that have maybe a data point every kilometer or something. 00:01:14.630 --> 00:01:20.230 These are generated with satellite altimeters that are really using gravity to infer what the shape might be. 00:01:20.430 --> 00:01:26.360 When we get there and we look at it with the shipboard multibeam, we're like, "holy cow! This is not what we expected." 00:01:27.785 --> 00:01:32.100 So sometimes the seamounts that we've been diving on, some of them have data, and some of them didn't have data. 00:01:32.300 --> 00:01:34.510 And the ones that didn't have data, we're mapping the night before. 00:01:34.710 --> 00:01:38.630 And sometimes when we map them, we can say, "okay, we want to get to the seamount; 00:01:38.830 --> 00:01:45.450 based on this altimetery data, we think it's 3,000 meters high, or 3,000 meters off the seafloor." 00:01:45.650 --> 00:01:48.850 Then we get there and it's only 2,000 meters high. 00:01:49.050 --> 00:01:54.130 Well, now all of a sudden our dive has changed 1,000 meters in depth, so now we're diving in a totally different region as well. 00:01:54.330 --> 00:01:59.050 So, this is why we do the mapping, because you never know exactly what you're going to see down there. 00:01:59.250 --> 00:02:04.180 And we've seen several times on this expedition so far kilometers in difference 00:02:04.380 --> 00:02:06.540 of what we thought how high these seamounts are going to be. 00:02:07.682 --> 00:02:12.890 Every time that we get a little bit more information about them and we're able to put together a better picture, a higher-resolution map, 00:02:13.090 --> 00:02:17.810 we learn more about what a seamount is, what it's history is, and what potential communities live on them. 00:02:21.276 --> 00:02:23.460 So, once we have a map, we are able to pick a dive target. 00:02:24.086 --> 00:02:27.050 We then take our remotely operated vehicles and go down and explore the seafloor. 00:02:27.858 --> 00:02:37.510 While we're there, we're able to collect high-resolution detailed imagery to specifically target in situ observations of lava flows, of eroded carbonate. 00:02:37.710 --> 00:02:41.010 You can learn a lot from just by looking at the rocks. 00:02:41.976 --> 00:02:49.080 Then we'll go down, the shipboard multibeam was giving us a depth reading every 70 meters or so, depending on how we're gridding it, 00:02:49.280 --> 00:02:54.030 and we go down with the ROV and we start looking at things on meter by meter or few meters scale 00:02:54.230 --> 00:02:57.880 and we see all sorts of relief and topography that don't show up in that data. 00:02:58.704 --> 00:03:02.090 We've been able to really see some clear volcanic features on some of these seamounts. 00:03:02.290 --> 00:03:05.120 We saw spectacular kind of collapsed lava tubes in one. 00:03:05.320 --> 00:03:09.050 So there's this record of things that went on tens of millions of years ago, 00:03:09.250 --> 00:03:13.740 that we can go down with the ROV and look at today which is just amazing. 00:03:17.374 --> 00:03:23.700 In order to figure out how these seamounts formed and to get more information about how old they are and what their history is, 00:03:23.900 --> 00:03:25.200 we have to collect a rock sample. 00:03:26.165 --> 00:03:30.120 So once we collect a rock during an ROV dive, we bring it back to the surface, we dry it, 00:03:30.320 --> 00:03:34.430 and then we prepare it to be sent to a museum or a public repository 00:03:34.630 --> 00:03:38.420 where the science community can then access it and begin the aging and dating process. 00:03:39.936 --> 00:03:41.670 We want to sample rocks for a couple of reasons. 00:03:41.870 --> 00:03:45.390 One, we can look at their geochemistry and we can compare it with the 00:03:45.590 --> 00:03:49.400 geochemistry of other rocks that tells us if those lavas might have had a common origin. 00:03:50.023 --> 00:03:54.330 The other is, we can use radiometric isotopes to actually date a rock. 00:03:54.530 --> 00:04:00.750 So when a rock forms, it takes in certain elements and some of those elements change through time at a known rate. 00:04:00.950 --> 00:04:03.370 And we can use that to constrain the age of the rock. 00:04:03.570 --> 00:04:05.560 So we did get a couple of small rock samples. 00:04:05.760 --> 00:04:10.800 And we're hopeful that we'll be able to do geochemical analysis as well as get an age date from those rocks. 00:04:14.091 --> 00:04:19.230 So one of the most exciting things about this expedition is that we're able to get a first look at a lot of these seamounts. 00:04:19.430 --> 00:04:26.097 We mapped them for the first time and then we're able to conduct ROV dives and see the first-ever in situ observations on the seafloor. 00:04:26.300 --> 00:04:29.320 We then can collect biological and geological samples, 00:04:29.520 --> 00:04:33.730 which give us an opportunity to learn more about the communities as well as date the volcanic features. 00:04:36.260 --> 00:04:41.570 All of the mapping data that we collect, all of the ROV footage, all of the rock samples, the biological samples, 00:04:41.770 --> 00:04:46.350 scientists from all over the country and all over the world will have a chance to actually use these data. 00:04:46.550 --> 00:04:51.810 And a whole lot of people will use this down the road and that's really an exciting way to do business, I think. 00:04:53.077 --> 00:04:58.080 Being able to explore at those different scales, all within 24 hours, going from a totally unknown seamount 00:04:58.280 --> 00:05:02.810 to a seamount that has beautiful images and biologic and geologic samples, 00:05:03.010 --> 00:05:06.010 we're happy to support that and love doing it. 00:05:06.210 --> 00:05:10.480 It's sort of exploration from the ground up, right?