TEDxPSU
Liz Hajek: What rivers can tell us about the earth's history
Liz Hajek: 河流告诉我们的地球历史
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河流是自然最强大的力量之一——它们推动高山，侵蚀大地，而且河道也一直在变化。理解它们如何形成以及如何变化对居住在河岸旁和三角洲的人来说十分重要。在这一图片信息丰富的演讲中，地质学家Liz Hajek向我们展示了由古代河流堆积成的岩石如何可以被用作时间机器来研究地球的历史，从而让我们得知在今天应当如何可持续的生存下去。
Liz Hajek - Geoscientist
Liz Hajek studies sedimentary rocks to understand how landscapes change and evolve. Full bio
Liz Hajek studies sedimentary rocks to understand how landscapes change and evolve. Full bio
Double-click the English transcript below to play the video.
00:12
All right, let's get up
our picture of the earth.
our picture of the earth.
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好的，我们来看看地球的照片。
00:16
The earth is pretty awesome.
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地球确实令人惊叹。
00:18
I'm a geologist, so I get
pretty psyched about this,
pretty psyched about this,
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我是名地质学家，所以对这很着迷，
地球很伟大。
00:20
but the earth is great.
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00:21
It's powerful, it's dynamic,
it's constantly changing.
it's constantly changing.
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它充满力量，充满活力，
时时刻刻都在变化。
时时刻刻都在变化。
确实是个令人兴奋的居住地。
00:25
It's a pretty exciting place to live.
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00:28
But I want to share with you guys today
my perspective as a geologist
my perspective as a geologist
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但我今天想从一个地质学家的视角
和你们分享，了解地球的过去
00:32
in how understanding earth's past
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00:34
can help inform and guide
decisions that we make today
decisions that we make today
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将如何帮助并指导我们在地球上
可持续的生存下去。
00:37
about how to sustainably live
on earth's surface.
on earth's surface.
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00:41
So there's a lot of exciting things
that go on on the surface of the earth.
that go on on the surface of the earth.
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地球表面有着许多令人兴奋的事物。
如果我们在这里放大一点，
00:45
If we zoom in here a little bit,
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00:47
I want to talk to you guys a little bit
about one of the things that happens.
about one of the things that happens.
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我想和你们谈谈一个现象。
物质在地球的表面不断被冲刷，
00:51
Material get shuffled around
earth's surface all the time,
earth's surface all the time,
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其中一个重要的影响是，
高山上的东西也会被冲刷掉，
高山上的东西也会被冲刷掉，
00:53
and one of the big thing that happens
is material from high mountains
is material from high mountains
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被搬运并最终沉淀于海底。
00:57
gets eroded and transported
and deposited in the sea.
and deposited in the sea.
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这一过程一直发生着，
00:59
And this process is ongoing all the time,
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并且深刻的影响了地形的形成。
01:01
and it has huge effects
on how the landscape works.
on how the landscape works.
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举个例子，在印度南部
01:03
So this example here in south India --
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01:05
we have some of the biggest
mountains in the world,
mountains in the world,
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有着世界上最高的山峰，
01:08
and you can see in this satellite photo
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你可以从这张卫星图像上看到，
01:10
rivers transporting material
from those mountains out to the sea.
from those mountains out to the sea.
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河流运输着这些山上的东西直至海洋。
你可以把这些河流想象成推土机。
01:14
You can think of these rivers
like bulldozers.
like bulldozers.
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它们基本上就是在拽着这些山峰，
将它们向海的方向推移。
将它们向海的方向推移。
01:16
They're basically taking these mountains
and pushing them down towards the sea.
and pushing them down towards the sea.
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01:21
We'll give you guys an example here.
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给你们举个例子。
01:23
So we zoom in a little bit.
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我们放大一点。
我想和你们具体谈谈其中一条河。
01:24
I want to talk to you guys
specifically about a river.
specifically about a river.
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我们可以看到河流
运输物质到海洋的过程中，
运输物质到海洋的过程中，
01:27
We can see these beautiful patterns
that the rivers make
that the rivers make
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描绘出的美丽图案，
01:29
as they're pushing material
down to the sea,
down to the sea,
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但是这些图案不是一成不变的。
01:32
but these patterns aren't static.
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这些河流这里绕一绕，那里绕一绕，
01:33
These rivers are wiggling
and jumping around quite a bit,
and jumping around quite a bit,
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就会对我们的生活产生很大的影响。
01:36
and it can have big impacts on our lives.
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其中一个例子是戈西河。
01:38
So an example of this
is this is the Kosi River.
is this is the Kosi River.
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01:40
So the Kosi River
has this nice c-shaped pathway,
has this nice c-shaped pathway,
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戈西河有着漂亮的C形河道，
01:43
and it exits the big mountains of Nepal
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它从尼泊尔的高山流出，
带着成吨的矿物，
01:45
carrying with it a ton of material,
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通过侵蚀高山得到的沉积物，
01:48
a lot of sediments that's being
eroded from the high mountains,
eroded from the high mountains,
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穿过印度，
01:51
and it spreads out across India
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并且运输着它们。
01:52
and moves this material.
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01:54
So we're going to zoom in to this area
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我们将放大这一块区域，
01:56
and I'm going to tell you a little bit
about what happened with the Kosi.
about what happened with the Kosi.
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而我将告诉你们戈西河发生的事情。
这个例子告诉了我们
这些系统的动态程度。
这些系统的动态程度。
02:00
It's an example of how dynamic
these systems can be.
these systems can be.
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这是2008年八月的一张卫星图像，
02:02
So this is a satellite image
from August of 2008,
from August of 2008,
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已经被着色了，
02:06
and this satellite image is colored
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所以植物或植被都是绿色的，
02:08
so that vegetations or plants
show up as green
show up as green
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水是蓝色的。
02:10
and water shows up as blue.
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你可以看到当它离开尼泊尔时
02:12
So here again you can see
that c-shaped pathway
that c-shaped pathway
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是呈C形的河道。
02:15
that this river takes as it exits Nepal.
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02:18
And now this is monsoon season.
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现在是季风季节。
02:20
August is monsoon season
in this region of the world,
in this region of the world,
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八月是这个地区的季风季节，
任何住在河流旁边的人都对洪水
02:22
and anyone that lives near a river
is no stranger to flooding
is no stranger to flooding
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以及洪水带来的危害
和不便不感到陌生。
和不便不感到陌生。
02:25
and the hazards and inconveniences
at minimum that are associated with that.
at minimum that are associated with that.
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02:29
But something interesting
happened in 2008,
happened in 2008,
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但是2008年发生了有趣的事情，
02:31
and this river moved in a way
that's very different.
that's very different.
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这条河流以十分不同的方式变化了。
它以与平常不同的方式造成了洪水。
02:34
It flooded in a way that's very
different than it normally does.
different than it normally does.
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戈西河流到这里，
02:37
So the Kosi River is flowing down here,
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02:40
but sometimes as these rivers
are bulldozing sediment,
are bulldozing sediment,
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但是有时随着这些河流
运输的沉积物越来越多，
运输的沉积物越来越多，
河道开始堵塞了，
02:43
they kind of get clogged,
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而这些堵塞实际上可以
02:44
and these clogs can
actually cause the rivers
actually cause the rivers
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导致河流走向的巨大变动。
02:46
to shift their course dramatically.
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这是仅仅两周后的卫星图像。
02:48
So this satellite image
is from just two weeks later.
is from just two weeks later.
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这是之前的河道，
02:51
Here's the previous pathway,
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那C形的河道，
02:53
that c-shaped pathway,
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你会发现它不再是蓝的了。
02:54
and you notice it's not blue anymore.
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现在蓝色的河道，
02:56
But now what we have is this blue pathway
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在图中央纵切了一刀。
02:58
that cuts down the middle
of the field of view here.
of the field of view here.
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现实中，戈西河漫上了它的河堤，
03:01
What happened is
the Kosi River jumped its banks,
the Kosi River jumped its banks,
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还有这里的比例尺是40英里。
03:03
and for reference,
the scale bar here is 40 miles.
the scale bar here is 40 miles.
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这条河十分突然的
移动了超过30英里。
移动了超过30英里。
03:06
This river moved
over 30 miles very abruptly.
over 30 miles very abruptly.
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03:10
So this river got clogged
and it jumped its banks.
and it jumped its banks.
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这条河堵住了，然后漫过了河堤。
03:13
Here's an image from about a week later,
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这是一周后的一张图片，
你可以看到这些是之前的河道，
03:15
and you can see
these are the previous pathways,
these are the previous pathways,
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而且漫堤的过程仍在继续，
03:18
and you can see this process
of river-jumping continues
of river-jumping continues
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这条河离它的主道越来越远。
03:20
as this river moves farther away
from its major course.
from its major course.
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03:23
So you can imagine
in landscapes like this,
in landscapes like this,
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所以你可以想象，
03:26
where rivers move around frequently,
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在这种河流经常改道的地形里，
理解河流何时、何地以及
如何改道是十分重要的。
如何改道是十分重要的。
03:28
it's really important to understand when,
where and how they're going to jump.
where and how they're going to jump.
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但是这种过程同样也发生在我们身边。
03:33
But these kinds of processes
also happen a lot closer to home as well.
also happen a lot closer to home as well.
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03:37
So in the United States,
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在美国，
03:39
we have the Mississippi River
that drains most of the continental US.
that drains most of the continental US.
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密西西比河流经大部分的美洲大陆。
它推动着来自落基山脉
03:43
It pushes material
from the Rocky Mountains
from the Rocky Mountains
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和大平原的物质。
03:45
and from the Great Plains.
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它夹带着这些物质贯穿美国，
03:47
It drains it and moves it
all the way across America
all the way across America
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然后把它们倒入墨西哥湾。
03:50
and dumps it out in the Gulf of Mexico.
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03:53
So this is the course of the Mississippi
that we're familiar with today,
that we're familiar with today,
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这是我们今天熟悉的密西西比河河道，
但是它并非一直是按这个方向流动的。
03:56
but it didn't always flow
in this direction.
in this direction.
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如果我们利用地质记录，
03:58
If we use the geologic record,
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就可以重建它过去的走向。
04:00
we can reconstruct
where it went in the past.
where it went in the past.
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04:04
So for example, this red area here
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举个例子，这里红色的区域
04:06
is where we know the Mississippi River
flowed and deposited material
flowed and deposited material
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据我们目前所知，是大约
4600年前密西西比河流过
4600年前密西西比河流过
并且沉积物质的地方。
04:10
about 4,600 years ago.
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04:12
Then about 3,500 years ago it moved
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然后大约在3500年前，
04:14
to follow the course
outlined here in orange.
outlined here in orange.
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它移动到了橘色标注的河道流动。
它一直移动，不停移动。
04:16
And it kept moving and it keeps moving.
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04:18
So here's about 2,000 years ago,
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这是约2000年前，
1000年前，
04:20
a thousand years ago,
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700年前。
04:22
700 years ago.
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直到500年前，
04:23
And it was only
as recently as 500 years ago
as recently as 500 years ago
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它才移动到了我们今天熟悉的河道。
04:26
that it occupied the pathway
that we're familiar with today.
that we're familiar with today.
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04:30
So these processes are really important,
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这些过程十分重要，
04:32
and especially here, this delta area,
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特别是这里，这个三角洲，
在这个三角洲里密西西比河
不断漫堤和改道，
不断漫堤和改道，
04:34
where these river-jumping events
in the Mississippi
in the Mississippi
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于是在陆地和海洋的交界处
形成了（新的）陆地。
形成了（新的）陆地。
04:38
are building land at the interface
of the land and the sea.
of the land and the sea.
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这是非常宝贵的资产，
04:41
This is really valuable real estate,
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像这样的三角洲是我们星球上
人口最稠密的地区。
人口最稠密的地区。
04:43
and deltas like this are some of the most
densely populated areas on our planet.
densely populated areas on our planet.
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所以了解这些地形的动态变化，
04:48
So understanding the dynamics
of these landscapes,
of these landscapes,
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它们如何形成，在未来将如何继续演化
04:51
how they formed and how they will
continue to change in the future
continue to change in the future
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对于生活在那里的人们十分重要。
04:54
is really important
for the people that live there.
for the people that live there.
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04:57
So rivers also wiggle.
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河流也会轻微摆动。
04:59
These are sort of bigger jumps
that we've been talking about.
that we've been talking about.
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我们刚才谈到的是更大的漫堤过程。
我想向你们展示这里的一些河流摆动。
05:01
I want to show you guys
some river wiggles here.
some river wiggles here.
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我们转移到亚马逊河流域，
05:04
So we're going to fly down
to the Amazon River basin,
to the Amazon River basin,
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类似的，这里有一个巨大的河流系统，
05:06
and here again we have a big river system
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不断冲刷，转移着
安第斯山脉上的物质，
安第斯山脉上的物质，
05:08
that is draining and moving and plowing
material from the Andean Mountains,
material from the Andean Mountains,
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携带着它们穿越南美大陆，
05:13
transporting it across South America
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最终它们被倾入大西洋。
05:15
and dumping it out
into the Atlantic Ocean.
into the Atlantic Ocean.
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05:18
So if we zoom in here, you guys
can see these nice, curvy river pathways.
can see these nice, curvy river pathways.
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如果我们在这里放大，
你们可以看到这些蜿蜒曲折的河道。
你们可以看到这些蜿蜒曲折的河道。
05:23
Again, they're really beautiful,
but again, they're not static.
but again, they're not static.
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同样的，它们十分美丽，但又不稳定。
这些河流的走向不停扭曲变动。
05:26
These rivers wiggle around.
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我们可以利用最近30年的卫星图像
05:28
We can use satellite imagery
over the last 30 or so years
over the last 30 or so years
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05:31
to actually monitor how these change.
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来实际观察这是如何变化的。
05:33
So take a minute and just watch
any bend or curve in this river,
any bend or curve in this river,
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花点时间看看这条河
任何地方的弯曲，
任何地方的弯曲，
你会发现它并不会在一个地方呆很久。
05:38
and you'll see it doesn't stay
in the same place for very long.
in the same place for very long.
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它会不断变化，演变，改变图案。
05:41
It changes and evolves
and warps its pattern.
and warps its pattern.
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05:44
If you look in this area in particular,
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如果你再仔细看看这块区域，
05:47
I want you guys to notice
there's a sort of a loop in the river
there's a sort of a loop in the river
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我想让你们关注到河流中
有一个类似圆圈的地方，
有一个类似圆圈的地方，
完完全全的被分隔开来了。
05:50
that gets completely cut off.
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05:51
It's almost like a whip cracking
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它就像个马鞭，
从河流的某个位置被分开了。
05:53
and snaps off the pathway
of the river at a certain spot.
of the river at a certain spot.
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05:56
So just for reference, again,
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方便大家参考，
05:58
in this location, that river
changed its course over four miles
changed its course over four miles
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在这个地方，河流在一到两个季节里
将它的河道移动了将近四英里。
06:02
over the course of a season or two.
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06:05
So the landscapes
that we live in on earth,
that we live in on earth,
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所以我们所居住的这个地球上的
地形其实是不断在变化的：
地形其实是不断在变化的：
06:08
as this material
is being eroded from the mountains
is being eroded from the mountains
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随着高山上的物质被不断侵蚀，
不断被运输到海洋，
06:10
and transported to the sea,
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地形也在不断地发生变化，
06:11
are wiggling around all the time.
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它们时时刻刻都在变化着，
06:13
They're changing all the time,
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而我们需要理解这些过程
06:14
and we need to be able
to understand these processes
to understand these processes
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以便于可持续的生存在这些地形之中。
06:17
so we can manage and live
sustainably on these landscapes.
sustainably on these landscapes.
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但如果仅仅知道地表发生了什么，
06:20
But it's hard to do
if the only information we have
if the only information we have
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仍不足以为可持续的生存指明方向。
06:23
is what's going on today
at earth's surface.
at earth's surface.
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我们的观测还不够。
06:25
Right? We don't have
a lot of observations.
a lot of observations.
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例如，我们只有近30年的卫星数据。
06:27
We only have 30 years' worth
of satellite photos, for example.
of satellite photos, for example.
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我们需要更多的观测来
更加深入地了解这些过程。
更加深入地了解这些过程。
06:32
We need more observations
to understand these processes more.
to understand these processes more.
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此外，我们需要了解
06:35
And additionally, we need to know
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随着人类不断占据和改造地表，
06:37
how these landscapes are going
to respond to changing climate
to respond to changing climate
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这些地形对气候的变化和
06:40
and to changing land use
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人类对土地的使用将会呈现怎样的反应。
06:41
as we continue to occupy
and modify earth's surface.
and modify earth's surface.
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06:45
So this is where the rocks come in.
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这就是为什么我们接下来会提到岩石。
06:47
So as rivers flow,
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随着河流流动，
随着它们不断将物质
从高山运送到海洋，
从高山运送到海洋，
06:50
as they're bulldozing material
from the mountains to the sea,
from the mountains to the sea,
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有的时候一些泥沙和石块会滞留在地面。
06:53
sometimes bits of sand and clay
and rock get stuck in the ground.
and rock get stuck in the ground.
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这些留在地面的沙石逐渐被掩埋，
06:56
And that stuff that gets stuck
in the ground gets buried,
in the ground gets buried,
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随着时间的流逝，
便形成了又大又厚的堆积，
便形成了又大又厚的堆积，
06:59
and through time, we get
big, thick accumulations of sediments
big, thick accumulations of sediments
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最终变成了岩石。
07:03
that eventually turn into rocks.
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这意味着，我们可以去到
07:05
What this means is that we can
go to places like this,
go to places like this,
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拥有大量沉积岩的地方，
07:07
where we see big, thick stacks
of sedimentary rocks,
of sedimentary rocks,
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回到过去，
07:10
and go back in time
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了解过去的地形是什么样子的。
07:12
and see what the landscapes
looked like in the past.
looked like in the past.
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从而我们可以重构
07:14
We can do this to help reconstruct
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并理解地球的地形演化过程。
07:16
and understand
how earth landscapes evolve.
how earth landscapes evolve.
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07:22
This is pretty convenient, too,
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这也非常方便，
07:23
because the earth has had
sort of an epic history. Right?
sort of an epic history. Right?
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因为地球有着宏伟的历史，对吧？
07:26
So this video here
is a reconstruction of paleogeography
is a reconstruction of paleogeography
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这个视频重构的是地球历史中
最开始的那6亿年的地表演变。
07:31
for just the first
600 million years of earth's history.
600 million years of earth's history.
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07:35
So just a little bit of time here.
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我们花了短短几秒就看完了（笑）。
07:37
So as the plates move around,
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随着板块移动，
我们知道气候变化了，
海平面变化了，
海平面变化了，
07:40
we know climate has changed,
sea level has changed,
sea level has changed,
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不同的地形和环境形成了，
07:43
we have a lot of different
types of landscapes
types of landscapes
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07:46
and different types of environments
that we can go back --
that we can go back --
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我们可以回到过去——
如果有时间机器的话——
07:49
if we have a time machine --
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我们可以回到过去进行观察，
07:51
we can go back and look at,
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而我们确实拥有一台时间机器，
07:52
and we do indeed have a time machine
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我们可以观察这段时间内堆积的岩石。
07:54
because we can look at the rocks
that were deposited at these times.
that were deposited at these times.
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举个例子，带你们到
07:57
So I'm going to give you
an example of this
an example of this
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地球历史上的一个特殊时期。
07:59
and take you to a special
time in earth's past.
time in earth's past.
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大约5500万年前，地球骤暖。
08:01
About 55 million years ago,
there was a really abrupt warming event,
there was a really abrupt warming event,
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当时大量的二氧化碳
08:05
and what happened was
a whole bunch of carbon dioxide
a whole bunch of carbon dioxide
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被释放到了地球的大气中，
08:07
was released into earth's atmosphere,
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这导致了快速并且极端的全球变暖。
08:09
and it caused a rapid
and pretty extreme global warming event.
and pretty extreme global warming event.
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我说的“暖和”是指超级暖和，
08:13
And when I say warm, I mean pretty warm,
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那时北至加拿大，南至巴塔哥尼亚，
08:15
that there were things
like crocodiles and palm trees
like crocodiles and palm trees
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都能找到鳄鱼和棕榈树。
08:18
as far north as Canada
and as far south as Patagonia.
and as far south as Patagonia.
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所以这的确是非常暖和的时期，
而且发生得非常突然。
而且发生得非常突然。
08:22
So this was a pretty warm time
and it happened really abruptly.
and it happened really abruptly.
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我们能做的，
08:25
So what we can do
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就是回到过去，找到当时沉积的岩石，
08:26
is we can go back and find rocks
that were deposited at this time
that were deposited at this time
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并且重构这些地形是
如何随全球变暖变化的。
如何随全球变暖变化的。
08:29
and reconstruct how the landscape changed
in response to this warming event.
in response to this warming event.
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08:33
So here, yay, rocks.
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这里，太好了，有岩石。
08:35
(Laughter)
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（笑声）
这是一堆岩石。
08:37
Here's a pile of rocks.
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这里黄色圈出的一片，
08:39
This yellow blob here,
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其实是一条古河道，
08:41
this is actually a fossil river,
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就像我刚才展示的卡通一样，
08:43
so just like this cartoon I showed,
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这些是5500万年前留下的沉积物。
08:44
these are deposits that were
laid down 55 million years ago.
laid down 55 million years ago.
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作为地质学家，
我们可以近距离的观测它们，
我们可以近距离的观测它们，
08:48
As geologists, we can go
and look at these up close
and look at these up close
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并且重构地形。
08:51
and reconstruct the landscape.
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08:53
So here's another example.
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还有一个例子。
08:54
The yellow blob here is a fossil river.
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这黄色范围内的一片是古河道。
在它上面还有一片。
08:57
Here's another one above it.
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我们可以到实地仔细考察、测量，
08:58
We can go and look in detail
and make measurements and observations,
and make measurements and observations,
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还可以观测它们的特征。
09:02
and we can measure features.
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例如，我刚刚标注的地方
09:03
For example, the features
I just highlighted there
I just highlighted there
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告诉我们这条河大约3英尺深。
09:05
tell us that this particular river
was probably about three feet deep.
was probably about three feet deep.
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如果你生活在5500万年前，
09:09
You could wade
across this cute little stream
across this cute little stream
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你可以涉水通过这条萌萌的小溪。
09:11
if you were walking around
55 million years ago.
55 million years ago.
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09:14
The reddish stuff that's above
and below those channels,
and below those channels,
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在这些渠道之上和之下的红色物质，
09:17
those are ancient soil deposits.
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是古代的土壤沉积。
我们可以通过它们知道在这片土地
生活和生长着什么样的生物，
生活和生长着什么样的生物，
09:19
So we can look at those to tell us
what lived and grew on the landscape
what lived and grew on the landscape
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并且了解这些河流是如何和
冲积平原相互影响的。
冲积平原相互影响的。
09:23
and to understand how these rivers
were interacting with their floodplains.
were interacting with their floodplains.
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09:27
So we can look in detail
and reconstruct with some specificity
and reconstruct with some specificity
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我们可以仔细的观测，准确的重构
这些河流的走向，以及地形的样貌。
09:32
how these rivers flowed
and what the landscapes looked like.
and what the landscapes looked like.
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现在当我们为这个地区重构过去的
09:34
So when we do this
for this particular place
for this particular place
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09:38
at this time,
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地形时，
如果我们看看
在这次突然变暖之前发生了什么，
在这次突然变暖之前发生了什么，
09:39
if we look what happened
before this abrupt warming event,
before this abrupt warming event,
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这些河流从高山到海洋开辟了一条道路，
09:42
the rivers kind of carved their way
down from the mountains to the sea,
down from the mountains to the sea,
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看上去和我向你们展示的
亚马逊流域很像。
亚马逊流域很像。
09:45
and they looked maybe similar to what
I showed you in the Amazon River basin.
I showed you in the Amazon River basin.
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但是气候变化刚一开始，
09:50
But right at the onset
of this climate change event,
of this climate change event,
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这些河流就发生了剧变。
09:53
the rivers change dramatically.
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09:55
All of a sudden they got much broader,
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首先它们一下子就变宽了许多，
09:57
and they started to slide back and forth
across the landscape more readily.
across the landscape more readily.
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其次它们在地表上的
改道活动更加频繁。
改道活动更加频繁。
10:01
Eventually, the rivers reverted
back to a state that was more similar
back to a state that was more similar
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最终，这些河流变回了
10:05
to what they would have looked like
before this climate event,
before this climate event,
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气候变暖之前的样子，
但这花了很长很长的时间。
10:09
but it took a long, long time.
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10:12
So we can go back in earth's time
and do these kinds of reconstructions
and do these kinds of reconstructions
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我们可以回到地球的过去，
做类似的重构，
做类似的重构，
10:16
and understand how
earth's landscape has changed
earth's landscape has changed
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了解地表是如何随着气候变化，
如之前提到的地球骤暖
如之前提到的地球骤暖
或土地使用的变化而变化的。
10:18
in response to a climate event like this
or a land use event.
or a land use event.
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河流产生变化一些方式，
10:22
So some of the ways that rivers change
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或是改变走向和水文活动的原因，
10:24
or the reasons that rivers change
their pattern and their movements
their pattern and their movements
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有一些是因为当地表有了更多的水，
10:29
is because of things like with extra water
falling on the land's surface
falling on the land's surface
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再加上气候变暖，
10:33
when climate is hotter,
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沉积物会被更加频繁地被运送或侵蚀，
10:35
we can move more sediment
and erode more sediment,
and erode more sediment,
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这些都会对河流产生影响。
10:37
and that changes how rivers behave.
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10:40
So ultimately,
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总而言之，
10:42
as long as earth's surface is our home,
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只要地球是我们的家园，
我们就需要小心的管理资源，
10:45
we need to carefully manage
the resources and risks
the resources and risks
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警惕生活在这种动态环境中的风险。
10:48
associated with living
in dynamic environments.
in dynamic environments.
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我认为我们能真正持续
这么做的唯一途径
这么做的唯一途径
10:51
And I think the only way
we can really do that sustainably
we can really do that sustainably
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是充分考虑在地球历史的
10:55
is if we include information
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慢慢长河中，地形的演变和走向。
10:58
about how landscapes evolved
and behaved in earth's past.
and behaved in earth's past.
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谢谢。
11:02
Thank you.
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（掌声）
11:03
(Applause)
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ABOUT THE SPEAKER
Liz Hajek - GeoscientistLiz Hajek studies sedimentary rocks to understand how landscapes change and evolve.
Why you should listen
Liz Hajek's research has contributed new perspectives on how rivers and coastlines move and how sediments record earth history. She is an assistant professor of geosciences at The Pennsylvania State University, where she teaches a range of courses spanning topics from oceanography to petroleum geology. Hajek and her students often conduct fieldwork in rugged places and use computer models and experiments to reveal the rhythms and dynamics of earth's surface. She recently appeared in the NOVA Treasures of the Earth: Power episode and has a paper in the Annual Review of Earth and Planetary Sciences.
More profile about the speakerLiz Hajek | Speaker | TED.com