[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.98,0:00:04.24,Default,,0000,0000,0000,,All right, let's get up\Nour picture of the earth.
Dialogue: 0,0:00:04.56,0:00:05.98,Default,,0000,0000,0000,,The earth is pretty awesome.
Dialogue: 0,0:00:06.00,0:00:08.43,Default,,0000,0000,0000,,I'm a geologist, so I get\Npretty psyched about this,
Dialogue: 0,0:00:08.45,0:00:09.82,Default,,0000,0000,0000,,but the earth is great.
Dialogue: 0,0:00:09.84,0:00:13.30,Default,,0000,0000,0000,,It's powerful, it's dynamic,\Nit's constantly changing.
Dialogue: 0,0:00:13.32,0:00:15.12,Default,,0000,0000,0000,,It's a pretty exciting place to live.
Dialogue: 0,0:00:16.28,0:00:19.98,Default,,0000,0000,0000,,But I want to share with you guys today\Nmy perspective as a geologist
Dialogue: 0,0:00:20.00,0:00:22.22,Default,,0000,0000,0000,,in how understanding earth's past
Dialogue: 0,0:00:22.24,0:00:25.74,Default,,0000,0000,0000,,can help inform and guide\Ndecisions that we make today
Dialogue: 0,0:00:25.76,0:00:28.84,Default,,0000,0000,0000,,about how to sustainably live\Non earth's surface.
Dialogue: 0,0:00:29.52,0:00:33.26,Default,,0000,0000,0000,,So there's a lot of exciting things\Nthat go on on the surface of the earth.
Dialogue: 0,0:00:33.28,0:00:34.84,Default,,0000,0000,0000,,If we zoom in here a little bit,
Dialogue: 0,0:00:35.36,0:00:39.02,Default,,0000,0000,0000,,I want to talk to you guys a little bit\Nabout one of the things that happens.
Dialogue: 0,0:00:39.04,0:00:41.79,Default,,0000,0000,0000,,Material get shuffled around\Nearth's surface all the time,
Dialogue: 0,0:00:41.80,0:00:45.04,Default,,0000,0000,0000,,and one of the big thing that happens\Nis material from high mountains
Dialogue: 0,0:00:45.06,0:00:47.54,Default,,0000,0000,0000,,gets eroded and transported\Nand deposited in the sea.
Dialogue: 0,0:00:47.56,0:00:49.52,Default,,0000,0000,0000,,And this process is ongoing all the time,
Dialogue: 0,0:00:49.55,0:00:51.94,Default,,0000,0000,0000,,and it has huge effects\Non how the landscape works.
Dialogue: 0,0:00:51.96,0:00:53.86,Default,,0000,0000,0000,,So this example here in south India --
Dialogue: 0,0:00:53.88,0:00:56.38,Default,,0000,0000,0000,,we have some of the biggest\Nmountains in the world,
Dialogue: 0,0:00:56.40,0:00:58.38,Default,,0000,0000,0000,,and you can see in this satellite photo
Dialogue: 0,0:00:58.40,0:01:02.58,Default,,0000,0000,0000,,rivers transporting material\Nfrom those mountains out to the sea.
Dialogue: 0,0:01:02.60,0:01:04.78,Default,,0000,0000,0000,,You can think of these rivers\Nlike bulldozers.
Dialogue: 0,0:01:04.80,0:01:08.52,Default,,0000,0000,0000,,They're basically taking these mountains\Nand pushing them down towards the sea.
Dialogue: 0,0:01:09.44,0:01:11.26,Default,,0000,0000,0000,,We'll give you guys an example here.
Dialogue: 0,0:01:11.28,0:01:12.62,Default,,0000,0000,0000,,So we zoom in a little bit.
Dialogue: 0,0:01:12.64,0:01:15.18,Default,,0000,0000,0000,,I want to talk to you guys\Nspecifically about a river.
Dialogue: 0,0:01:15.20,0:01:17.86,Default,,0000,0000,0000,,We can see these beautiful patterns\Nthat the rivers make
Dialogue: 0,0:01:17.88,0:01:19.98,Default,,0000,0000,0000,,as they're pushing material\Ndown to the sea,
Dialogue: 0,0:01:20.00,0:01:21.62,Default,,0000,0000,0000,,but these patterns aren't static.
Dialogue: 0,0:01:21.64,0:01:24.33,Default,,0000,0000,0000,,These rivers are wiggling\Nand jumping around quite a bit,
Dialogue: 0,0:01:24.35,0:01:26.32,Default,,0000,0000,0000,,and it can have big impacts on our lives.
Dialogue: 0,0:01:26.34,0:01:28.74,Default,,0000,0000,0000,,So an example of this\Nis this is the Kosi River.
Dialogue: 0,0:01:28.76,0:01:31.42,Default,,0000,0000,0000,,So the Kosi River\Nhas this nice c-shaped pathway,
Dialogue: 0,0:01:31.44,0:01:33.90,Default,,0000,0000,0000,,and it exits the big mountains of Nepal
Dialogue: 0,0:01:33.92,0:01:36.06,Default,,0000,0000,0000,,carrying with it a ton of material,
Dialogue: 0,0:01:36.08,0:01:39.05,Default,,0000,0000,0000,,a lot of sediments that's being\Neroded from the high mountains,
Dialogue: 0,0:01:39.07,0:01:40.93,Default,,0000,0000,0000,,and it spreads out across India
Dialogue: 0,0:01:40.95,0:01:42.27,Default,,0000,0000,0000,,and moves this material.
Dialogue: 0,0:01:42.56,0:01:44.86,Default,,0000,0000,0000,,So we're going to zoom in to this area
Dialogue: 0,0:01:44.88,0:01:48.31,Default,,0000,0000,0000,,and I'm going to tell you a little bit\Nabout what happened with the Kosi.
Dialogue: 0,0:01:48.33,0:01:50.90,Default,,0000,0000,0000,,It's an example of how dynamic\Nthese systems can be.
Dialogue: 0,0:01:50.92,0:01:54.50,Default,,0000,0000,0000,,So this is a satellite image\Nfrom August of 2008,
Dialogue: 0,0:01:54.52,0:01:56.22,Default,,0000,0000,0000,,and this satellite image is colored
Dialogue: 0,0:01:56.24,0:01:58.42,Default,,0000,0000,0000,,so that vegetations or plants\Nshow up as green
Dialogue: 0,0:01:58.44,0:02:00.10,Default,,0000,0000,0000,,and water shows up as blue.
Dialogue: 0,0:02:00.12,0:02:03.66,Default,,0000,0000,0000,,So here again you can see\Nthat c-shaped pathway
Dialogue: 0,0:02:03.68,0:02:05.60,Default,,0000,0000,0000,,that this river takes as it exits Nepal.
Dialogue: 0,0:02:06.12,0:02:08.14,Default,,0000,0000,0000,,And now this is monsoon season.
Dialogue: 0,0:02:08.16,0:02:10.66,Default,,0000,0000,0000,,August is monsoon season\Nin this region of the world,
Dialogue: 0,0:02:10.68,0:02:13.58,Default,,0000,0000,0000,,and anyone that lives near a river\Nis no stranger to flooding
Dialogue: 0,0:02:13.60,0:02:17.17,Default,,0000,0000,0000,,and the hazards and inconveniences\Nat minimum that are associated with that.
Dialogue: 0,0:02:17.44,0:02:19.70,Default,,0000,0000,0000,,But something interesting\Nhappened in 2008,
Dialogue: 0,0:02:19.72,0:02:22.62,Default,,0000,0000,0000,,and this river moved in a way\Nthat's very different.
Dialogue: 0,0:02:22.64,0:02:25.64,Default,,0000,0000,0000,,It flooded in a way that's very\Ndifferent than it normally does.
Dialogue: 0,0:02:25.66,0:02:28.42,Default,,0000,0000,0000,,So the Kosi River is flowing down here,
Dialogue: 0,0:02:28.44,0:02:31.02,Default,,0000,0000,0000,,but sometimes as these rivers\Nare bulldozing sediment,
Dialogue: 0,0:02:31.04,0:02:32.30,Default,,0000,0000,0000,,they kind of get clogged,
Dialogue: 0,0:02:32.32,0:02:34.46,Default,,0000,0000,0000,,and these clogs can\Nactually cause the rivers
Dialogue: 0,0:02:34.48,0:02:36.18,Default,,0000,0000,0000,,to shift their course dramatically.
Dialogue: 0,0:02:36.20,0:02:39.06,Default,,0000,0000,0000,,So this satellite image\Nis from just two weeks later.
Dialogue: 0,0:02:39.08,0:02:41.02,Default,,0000,0000,0000,,Here's the previous pathway,
Dialogue: 0,0:02:41.04,0:02:42.66,Default,,0000,0000,0000,,that c-shaped pathway,
Dialogue: 0,0:02:42.68,0:02:44.78,Default,,0000,0000,0000,,and you notice it's not blue anymore.
Dialogue: 0,0:02:44.80,0:02:46.78,Default,,0000,0000,0000,,But now what we have is this blue pathway
Dialogue: 0,0:02:46.80,0:02:49.26,Default,,0000,0000,0000,,that cuts down the middle\Nof the field of view here.
Dialogue: 0,0:02:49.28,0:02:51.62,Default,,0000,0000,0000,,What happened is\Nthe Kosi River jumped its banks,
Dialogue: 0,0:02:51.64,0:02:54.34,Default,,0000,0000,0000,,and for reference,\Nthe scale bar here is 40 miles.
Dialogue: 0,0:02:54.36,0:02:57.88,Default,,0000,0000,0000,,This river moved\Nover 30 miles very abruptly.
Dialogue: 0,0:02:58.56,0:03:01.74,Default,,0000,0000,0000,,So this river got clogged\Nand it jumped its banks.
Dialogue: 0,0:03:01.76,0:03:03.86,Default,,0000,0000,0000,,Here's an image from about a week later,
Dialogue: 0,0:03:03.88,0:03:06.14,Default,,0000,0000,0000,,and you can see\Nthese are the previous pathways,
Dialogue: 0,0:03:06.16,0:03:08.82,Default,,0000,0000,0000,,and you can see this process\Nof river-jumping continues
Dialogue: 0,0:03:08.84,0:03:11.41,Default,,0000,0000,0000,,as this river moves farther away\Nfrom its major course.
Dialogue: 0,0:03:11.92,0:03:13.98,Default,,0000,0000,0000,,So you can imagine\Nin landscapes like this,
Dialogue: 0,0:03:14.00,0:03:16.62,Default,,0000,0000,0000,,where rivers move around frequently,
Dialogue: 0,0:03:16.64,0:03:21.14,Default,,0000,0000,0000,,it's really important to understand when,\Nwhere and how they're going to jump.
Dialogue: 0,0:03:21.16,0:03:25.04,Default,,0000,0000,0000,,But these kinds of processes\Nalso happen a lot closer to home as well.
Dialogue: 0,0:03:25.64,0:03:27.46,Default,,0000,0000,0000,,So in the United States,
Dialogue: 0,0:03:27.48,0:03:31.54,Default,,0000,0000,0000,,we have the Mississippi River\Nthat drains most of the continental US.
Dialogue: 0,0:03:31.56,0:03:33.94,Default,,0000,0000,0000,,It pushes material\Nfrom the Rocky Mountains
Dialogue: 0,0:03:33.96,0:03:35.50,Default,,0000,0000,0000,,and from the Great Plains.
Dialogue: 0,0:03:35.52,0:03:38.74,Default,,0000,0000,0000,,It drains it and moves it\Nall the way across America
Dialogue: 0,0:03:38.76,0:03:40.68,Default,,0000,0000,0000,,and dumps it out in the Gulf of Mexico.
Dialogue: 0,0:03:41.32,0:03:44.78,Default,,0000,0000,0000,,So this is the course of the Mississippi\Nthat we're familiar with today,
Dialogue: 0,0:03:44.80,0:03:46.90,Default,,0000,0000,0000,,but it didn't always flow\Nin this direction.
Dialogue: 0,0:03:46.92,0:03:48.58,Default,,0000,0000,0000,,If we use the geologic record,
Dialogue: 0,0:03:48.60,0:03:51.32,Default,,0000,0000,0000,,we can reconstruct\Nwhere it went in the past.
Dialogue: 0,0:03:52.12,0:03:54.42,Default,,0000,0000,0000,,So for example, this red area here
Dialogue: 0,0:03:54.44,0:03:57.98,Default,,0000,0000,0000,,is where we know the Mississippi River\Nflowed and deposited material
Dialogue: 0,0:03:58.00,0:03:59.64,Default,,0000,0000,0000,,about 4,600 years ago.
Dialogue: 0,0:04:00.24,0:04:02.34,Default,,0000,0000,0000,,Then about 3,500 years ago it moved
Dialogue: 0,0:04:02.36,0:04:04.74,Default,,0000,0000,0000,,to follow the course\Noutlined here in orange.
Dialogue: 0,0:04:04.76,0:04:06.78,Default,,0000,0000,0000,,And it kept moving and it keeps moving.
Dialogue: 0,0:04:06.80,0:04:08.70,Default,,0000,0000,0000,,So here's about 2,000 years ago,
Dialogue: 0,0:04:08.72,0:04:10.42,Default,,0000,0000,0000,,a thousand years ago,
Dialogue: 0,0:04:10.44,0:04:11.66,Default,,0000,0000,0000,,700 years ago.
Dialogue: 0,0:04:11.68,0:04:14.10,Default,,0000,0000,0000,,And it was only\Nas recently as 500 years ago
Dialogue: 0,0:04:14.12,0:04:16.96,Default,,0000,0000,0000,,that it occupied the pathway\Nthat we're familiar with today.
Dialogue: 0,0:04:18.08,0:04:20.02,Default,,0000,0000,0000,,So these processes are really important,
Dialogue: 0,0:04:20.04,0:04:22.90,Default,,0000,0000,0000,,and especially here, this delta area,
Dialogue: 0,0:04:22.92,0:04:26.74,Default,,0000,0000,0000,,where these river-jumping events\Nin the Mississippi
Dialogue: 0,0:04:26.76,0:04:29.58,Default,,0000,0000,0000,,are building land at the interface\Nof the land and the sea.
Dialogue: 0,0:04:29.60,0:04:31.34,Default,,0000,0000,0000,,This is really valuable real estate,
Dialogue: 0,0:04:31.36,0:04:36.62,Default,,0000,0000,0000,,and deltas like this are some of the most\Ndensely populated areas on our planet.
Dialogue: 0,0:04:36.64,0:04:39.10,Default,,0000,0000,0000,,So understanding the dynamics\Nof these landscapes,
Dialogue: 0,0:04:39.12,0:04:42.26,Default,,0000,0000,0000,,how they formed and how they will\Ncontinue to change in the future
Dialogue: 0,0:04:42.28,0:04:44.68,Default,,0000,0000,0000,,is really important\Nfor the people that live there.
Dialogue: 0,0:04:45.48,0:04:47.02,Default,,0000,0000,0000,,So rivers also wiggle.
Dialogue: 0,0:04:47.04,0:04:49.94,Default,,0000,0000,0000,,These are sort of bigger jumps\Nthat we've been talking about.
Dialogue: 0,0:04:49.96,0:04:52.22,Default,,0000,0000,0000,,I want to show you guys\Nsome river wiggles here.
Dialogue: 0,0:04:52.24,0:04:54.78,Default,,0000,0000,0000,,So we're going to fly down\Nto the Amazon River basin,
Dialogue: 0,0:04:54.80,0:04:56.82,Default,,0000,0000,0000,,and here again we have a big river system
Dialogue: 0,0:04:56.84,0:05:01.22,Default,,0000,0000,0000,,that is draining and moving and plowing\Nmaterial from the Andean Mountains,
Dialogue: 0,0:05:01.24,0:05:03.06,Default,,0000,0000,0000,,transporting it across South America
Dialogue: 0,0:05:03.08,0:05:05.76,Default,,0000,0000,0000,,and dumping it out\Ninto the Atlantic Ocean.
Dialogue: 0,0:05:06.56,0:05:11.26,Default,,0000,0000,0000,,So if we zoom in here, you guys\Ncan see these nice, curvy river pathways.
Dialogue: 0,0:05:11.28,0:05:14.26,Default,,0000,0000,0000,,Again, they're really beautiful,\Nbut again, they're not static.
Dialogue: 0,0:05:14.28,0:05:16.02,Default,,0000,0000,0000,,These rivers wiggle around.
Dialogue: 0,0:05:16.04,0:05:19.66,Default,,0000,0000,0000,,We can use satellite imagery\Nover the last 30 or so years
Dialogue: 0,0:05:19.68,0:05:21.82,Default,,0000,0000,0000,,to actually monitor how these change.
Dialogue: 0,0:05:21.84,0:05:26.02,Default,,0000,0000,0000,,So take a minute and just watch\Nany bend or curve in this river,
Dialogue: 0,0:05:26.04,0:05:29.02,Default,,0000,0000,0000,,and you'll see it doesn't stay\Nin the same place for very long.
Dialogue: 0,0:05:29.04,0:05:31.32,Default,,0000,0000,0000,,It changes and evolves\Nand warps its pattern.
Dialogue: 0,0:05:32.84,0:05:35.22,Default,,0000,0000,0000,,If you look in this area in particular,
Dialogue: 0,0:05:35.24,0:05:38.22,Default,,0000,0000,0000,,I want you guys to notice\Nthere's a sort of a loop in the river
Dialogue: 0,0:05:38.24,0:05:39.66,Default,,0000,0000,0000,,that gets completely cut off.
Dialogue: 0,0:05:39.68,0:05:41.26,Default,,0000,0000,0000,,It's almost like a whip cracking
Dialogue: 0,0:05:41.28,0:05:43.96,Default,,0000,0000,0000,,and snaps off the pathway\Nof the river at a certain spot.
Dialogue: 0,0:05:44.36,0:05:45.98,Default,,0000,0000,0000,,So just for reference, again,
Dialogue: 0,0:05:46.00,0:05:50.94,Default,,0000,0000,0000,,in this location, that river\Nchanged its course over four miles
Dialogue: 0,0:05:50.96,0:05:52.64,Default,,0000,0000,0000,,over the course of a season or two.
Dialogue: 0,0:05:53.08,0:05:55.98,Default,,0000,0000,0000,,So the landscapes\Nthat we live in on earth,
Dialogue: 0,0:05:56.00,0:05:58.42,Default,,0000,0000,0000,,as this material\Nis being eroded from the mountains
Dialogue: 0,0:05:58.44,0:05:59.78,Default,,0000,0000,0000,,and transported to the sea,
Dialogue: 0,0:05:59.80,0:06:01.42,Default,,0000,0000,0000,,are wiggling around all the time.
Dialogue: 0,0:06:01.44,0:06:02.90,Default,,0000,0000,0000,,They're changing all the time,
Dialogue: 0,0:06:02.92,0:06:05.38,Default,,0000,0000,0000,,and we need to be able\Nto understand these processes
Dialogue: 0,0:06:05.40,0:06:08.14,Default,,0000,0000,0000,,so we can manage and live\Nsustainably on these landscapes.
Dialogue: 0,0:06:08.16,0:06:11.22,Default,,0000,0000,0000,,But it's hard to do\Nif the only information we have
Dialogue: 0,0:06:11.24,0:06:13.58,Default,,0000,0000,0000,,is what's going on today\Nat earth's surface.
Dialogue: 0,0:06:13.60,0:06:15.66,Default,,0000,0000,0000,,Right? We don't have\Na lot of observations.
Dialogue: 0,0:06:15.68,0:06:20.50,Default,,0000,0000,0000,,We only have 30 years' worth\Nof satellite photos, for example.
Dialogue: 0,0:06:20.52,0:06:23.42,Default,,0000,0000,0000,,We need more observations\Nto understand these processes more.
Dialogue: 0,0:06:23.44,0:06:25.06,Default,,0000,0000,0000,,And additionally, we need to know
Dialogue: 0,0:06:25.08,0:06:28.30,Default,,0000,0000,0000,,how these landscapes are going\Nto respond to changing climate
Dialogue: 0,0:06:28.32,0:06:29.58,Default,,0000,0000,0000,,and to changing land use
Dialogue: 0,0:06:29.60,0:06:32.44,Default,,0000,0000,0000,,as we continue to occupy\Nand modify earth's surface.
Dialogue: 0,0:06:33.16,0:06:35.70,Default,,0000,0000,0000,,So this is where the rocks come in.
Dialogue: 0,0:06:35.72,0:06:38.22,Default,,0000,0000,0000,,So as rivers flow,
Dialogue: 0,0:06:38.24,0:06:41.14,Default,,0000,0000,0000,,as they're bulldozing material\Nfrom the mountains to the sea,
Dialogue: 0,0:06:41.16,0:06:44.62,Default,,0000,0000,0000,,sometimes bits of sand and clay\Nand rock get stuck in the ground.
Dialogue: 0,0:06:44.64,0:06:47.34,Default,,0000,0000,0000,,And that stuff that gets stuck\Nin the ground gets buried,
Dialogue: 0,0:06:47.36,0:06:51.10,Default,,0000,0000,0000,,and through time, we get\Nbig, thick accumulations of sediments
Dialogue: 0,0:06:51.12,0:06:53.14,Default,,0000,0000,0000,,that eventually turn into rocks.
Dialogue: 0,0:06:53.16,0:06:55.74,Default,,0000,0000,0000,,What this means is that we can\Ngo to places like this,
Dialogue: 0,0:06:55.76,0:06:58.46,Default,,0000,0000,0000,,where we see big, thick stacks\Nof sedimentary rocks,
Dialogue: 0,0:06:58.48,0:06:59.98,Default,,0000,0000,0000,,and go back in time
Dialogue: 0,0:07:00.00,0:07:02.74,Default,,0000,0000,0000,,and see what the landscapes\Nlooked like in the past.
Dialogue: 0,0:07:02.76,0:07:04.90,Default,,0000,0000,0000,,We can do this to help reconstruct
Dialogue: 0,0:07:04.92,0:07:09.24,Default,,0000,0000,0000,,and understand\Nhow earth landscapes evolve.
Dialogue: 0,0:07:10.16,0:07:11.78,Default,,0000,0000,0000,,This is pretty convenient, too,
Dialogue: 0,0:07:11.80,0:07:14.78,Default,,0000,0000,0000,,because the earth has had\Nsort of an epic history. Right?
Dialogue: 0,0:07:14.80,0:07:19.62,Default,,0000,0000,0000,,So this video here\Nis a reconstruction of paleogeography
Dialogue: 0,0:07:19.64,0:07:23.26,Default,,0000,0000,0000,,for just the first\N600 million years of earth's history.
Dialogue: 0,0:07:23.28,0:07:25.26,Default,,0000,0000,0000,,So just a little bit of time here.
Dialogue: 0,0:07:25.28,0:07:28.02,Default,,0000,0000,0000,,So as the plates move around,
Dialogue: 0,0:07:28.04,0:07:31.18,Default,,0000,0000,0000,,we know climate has changed,\Nsea level has changed,
Dialogue: 0,0:07:31.20,0:07:34.86,Default,,0000,0000,0000,,we have a lot of different\Ntypes of landscapes
Dialogue: 0,0:07:34.88,0:07:37.62,Default,,0000,0000,0000,,and different types of environments\Nthat we can go back --
Dialogue: 0,0:07:37.64,0:07:39.02,Default,,0000,0000,0000,,if we have a time machine --
Dialogue: 0,0:07:39.04,0:07:40.38,Default,,0000,0000,0000,,we can go back and look at,
Dialogue: 0,0:07:40.40,0:07:42.14,Default,,0000,0000,0000,,and we do indeed have a time machine
Dialogue: 0,0:07:42.16,0:07:45.50,Default,,0000,0000,0000,,because we can look at the rocks\Nthat were deposited at these times.
Dialogue: 0,0:07:45.52,0:07:47.54,Default,,0000,0000,0000,,So I'm going to give you\Nan example of this
Dialogue: 0,0:07:47.56,0:07:49.78,Default,,0000,0000,0000,,and take you to a special\Ntime in earth's past.
Dialogue: 0,0:07:49.80,0:07:53.02,Default,,0000,0000,0000,,About 55 million years ago,\Nthere was a really abrupt warming event,
Dialogue: 0,0:07:53.04,0:07:55.54,Default,,0000,0000,0000,,and what happened was\Na whole bunch of carbon dioxide
Dialogue: 0,0:07:55.56,0:07:57.38,Default,,0000,0000,0000,,was released into earth's atmosphere,
Dialogue: 0,0:07:57.40,0:08:01.26,Default,,0000,0000,0000,,and it caused a rapid\Nand pretty extreme global warming event.
Dialogue: 0,0:08:01.28,0:08:03.94,Default,,0000,0000,0000,,And when I say warm, I mean pretty warm,
Dialogue: 0,0:08:03.96,0:08:06.94,Default,,0000,0000,0000,,that there were things\Nlike crocodiles and palm trees
Dialogue: 0,0:08:06.96,0:08:09.98,Default,,0000,0000,0000,,as far north as Canada\Nand as far south as Patagonia.
Dialogue: 0,0:08:10.00,0:08:13.18,Default,,0000,0000,0000,,So this was a pretty warm time\Nand it happened really abruptly.
Dialogue: 0,0:08:13.20,0:08:14.42,Default,,0000,0000,0000,,So what we can do
Dialogue: 0,0:08:14.44,0:08:17.50,Default,,0000,0000,0000,,is we can go back and find rocks\Nthat were deposited at this time
Dialogue: 0,0:08:17.52,0:08:21.12,Default,,0000,0000,0000,,and reconstruct how the landscape changed\Nin response to this warming event.
Dialogue: 0,0:08:21.56,0:08:23.46,Default,,0000,0000,0000,,So here, yay, rocks.
Dialogue: 0,0:08:23.48,0:08:25.82,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:08:25.84,0:08:27.58,Default,,0000,0000,0000,,Here's a pile of rocks.
Dialogue: 0,0:08:27.60,0:08:29.22,Default,,0000,0000,0000,,This yellow blob here,
Dialogue: 0,0:08:29.24,0:08:30.98,Default,,0000,0000,0000,,this is actually a fossil river,
Dialogue: 0,0:08:31.00,0:08:32.67,Default,,0000,0000,0000,,so just like this cartoon I showed,
Dialogue: 0,0:08:32.69,0:08:35.98,Default,,0000,0000,0000,,these are deposits that were\Nlaid down 55 million years ago.
Dialogue: 0,0:08:36.00,0:08:39.10,Default,,0000,0000,0000,,As geologists, we can go\Nand look at these up close
Dialogue: 0,0:08:39.12,0:08:40.55,Default,,0000,0000,0000,,and reconstruct the landscape.
Dialogue: 0,0:08:41.24,0:08:42.74,Default,,0000,0000,0000,,So here's another example.
Dialogue: 0,0:08:42.76,0:08:45.22,Default,,0000,0000,0000,,The yellow blob here is a fossil river.
Dialogue: 0,0:08:45.24,0:08:46.78,Default,,0000,0000,0000,,Here's another one above it.
Dialogue: 0,0:08:46.80,0:08:50.10,Default,,0000,0000,0000,,We can go and look in detail\Nand make measurements and observations,
Dialogue: 0,0:08:50.12,0:08:51.50,Default,,0000,0000,0000,,and we can measure features.
Dialogue: 0,0:08:51.52,0:08:53.90,Default,,0000,0000,0000,,For example, the features\NI just highlighted there
Dialogue: 0,0:08:53.92,0:08:57.38,Default,,0000,0000,0000,,tell us that this particular river\Nwas probably about three feet deep.
Dialogue: 0,0:08:57.40,0:08:59.50,Default,,0000,0000,0000,,You could wade\Nacross this cute little stream
Dialogue: 0,0:08:59.52,0:09:01.76,Default,,0000,0000,0000,,if you were walking around\N55 million years ago.
Dialogue: 0,0:09:02.48,0:09:05.38,Default,,0000,0000,0000,,The reddish stuff that's above\Nand below those channels,
Dialogue: 0,0:09:05.40,0:09:07.18,Default,,0000,0000,0000,,those are ancient soil deposits.
Dialogue: 0,0:09:07.20,0:09:11.06,Default,,0000,0000,0000,,So we can look at those to tell us\Nwhat lived and grew on the landscape
Dialogue: 0,0:09:11.08,0:09:14.64,Default,,0000,0000,0000,,and to understand how these rivers\Nwere interacting with their floodplains.
Dialogue: 0,0:09:15.68,0:09:20.06,Default,,0000,0000,0000,,So we can look in detail\Nand reconstruct with some specificity
Dialogue: 0,0:09:20.08,0:09:22.94,Default,,0000,0000,0000,,how these rivers flowed\Nand what the landscapes looked like.
Dialogue: 0,0:09:22.96,0:09:25.44,Default,,0000,0000,0000,,So when we do this\Nfor this particular place
Dialogue: 0,0:09:26.16,0:09:27.38,Default,,0000,0000,0000,,at this time,
Dialogue: 0,0:09:27.40,0:09:30.14,Default,,0000,0000,0000,,if we look what happened\Nbefore this abrupt warming event,
Dialogue: 0,0:09:30.16,0:09:33.78,Default,,0000,0000,0000,,the rivers kind of carved their way\Ndown from the mountains to the sea,
Dialogue: 0,0:09:33.80,0:09:38.94,Default,,0000,0000,0000,,and they looked maybe similar to what\NI showed you in the Amazon River basin.
Dialogue: 0,0:09:38.96,0:09:41.42,Default,,0000,0000,0000,,But right at the onset\Nof this climate change event,
Dialogue: 0,0:09:41.44,0:09:42.92,Default,,0000,0000,0000,,the rivers change dramatically.
Dialogue: 0,0:09:43.48,0:09:45.34,Default,,0000,0000,0000,,All of a sudden they got much broader,
Dialogue: 0,0:09:45.36,0:09:48.92,Default,,0000,0000,0000,,and they started to slide back and forth\Nacross the landscape more readily.
Dialogue: 0,0:09:49.88,0:09:53.78,Default,,0000,0000,0000,,Eventually, the rivers reverted\Nback to a state that was more similar
Dialogue: 0,0:09:53.80,0:09:57.62,Default,,0000,0000,0000,,to what they would have looked like\Nbefore this climate event,
Dialogue: 0,0:09:57.64,0:09:59.28,Default,,0000,0000,0000,,but it took a long, long time.
Dialogue: 0,0:10:00.24,0:10:04.10,Default,,0000,0000,0000,,So we can go back in earth's time\Nand do these kinds of reconstructions
Dialogue: 0,0:10:04.12,0:10:06.74,Default,,0000,0000,0000,,and understand how\Nearth's landscape has changed
Dialogue: 0,0:10:06.76,0:10:10.54,Default,,0000,0000,0000,,in response to a climate event like this\Nor a land use event.
Dialogue: 0,0:10:10.56,0:10:12.66,Default,,0000,0000,0000,,So some of the ways that rivers change
Dialogue: 0,0:10:12.68,0:10:17.46,Default,,0000,0000,0000,,or the reasons that rivers change\Ntheir pattern and their movements
Dialogue: 0,0:10:17.48,0:10:21.42,Default,,0000,0000,0000,,is because of things like with extra water\Nfalling on the land's surface
Dialogue: 0,0:10:21.44,0:10:23.38,Default,,0000,0000,0000,,when climate is hotter,
Dialogue: 0,0:10:23.40,0:10:25.94,Default,,0000,0000,0000,,we can move more sediment\Nand erode more sediment,
Dialogue: 0,0:10:25.96,0:10:27.80,Default,,0000,0000,0000,,and that changes how rivers behave.
Dialogue: 0,0:10:28.68,0:10:30.78,Default,,0000,0000,0000,,So ultimately,
Dialogue: 0,0:10:30.80,0:10:33.42,Default,,0000,0000,0000,,as long as earth's surface is our home,
Dialogue: 0,0:10:33.44,0:10:36.82,Default,,0000,0000,0000,,we need to carefully manage\Nthe resources and risks
Dialogue: 0,0:10:36.84,0:10:39.82,Default,,0000,0000,0000,,associated with living\Nin dynamic environments.
Dialogue: 0,0:10:39.84,0:10:43.78,Default,,0000,0000,0000,,And I think the only way\Nwe can really do that sustainably
Dialogue: 0,0:10:43.80,0:10:46.02,Default,,0000,0000,0000,,is if we include information
Dialogue: 0,0:10:46.04,0:10:50.14,Default,,0000,0000,0000,,about how landscapes evolved\Nand behaved in earth's past.
Dialogue: 0,0:10:50.16,0:10:51.38,Default,,0000,0000,0000,,Thank you.
Dialogue: 0,0:10:51.40,0:10:55.84,Default,,0000,0000,0000,,(Applause)