TEDxPSU
Liz Hajek: What rivers can tell us about the earth's history
麗滋海潔克: 河流能告訴我們哪些關於地球歷史的事
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河流是自然最強大的力量之一，它們能把山推平、能切開地球，而且河道經常在變動。對於居住在河岸以及三角洲的人，了解河流如何形成、以及它們如何改變是很重要的。在這場充滿視覺展示的演說，地質學家麗滋海潔克讓我們看到古河流如何造成岩石沉積，且這些資訊如何用來當作時光機，以研究地球的歷史，讓我們能探究現今要如何以更永續的方式生活。
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，我們先來看一下地球的圖片。
00:16
The earth is pretty awesome.
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地球是很了不起的。
00:18
I'm a geologist, so I get
pretty psyched about this,
pretty psyched about this,
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我是地質學家，
所以我對這點十分亢奮。
所以我對這點十分亢奮。
00:20
but the earth is great.
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但地球很棒，
00:21
It's powerful, it's dynamic,
it's constantly changing.
it's constantly changing.
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它很強大、它是動態的、
它不斷在改變，
它不斷在改變，
00:25
It's a pretty exciting place to live.
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住在地球是很讓人興奮的。
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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但我今天想和大家分享的，
是我身為地質學家的觀點，
是我身為地質學家的觀點，
00:32
in how understanding earth's past
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來談談了解地球的過去，
00:34
can help inform and guide
decisions that we make today
decisions that we make today
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如何能提供我們資訊和導引，
00:37
about how to sustainably live
on earth's surface.
on earth's surface.
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協助我們在現今做出關於
如何在地球表面永續居住的決策。
如何在地球表面永續居住的決策。
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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在地球表面上，
有許多讓人興奮的事物在發生。
有許多讓人興奮的事物在發生。
00:45
If we zoom in here a little bit,
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如果我們把這裡放大一點，
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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我想要跟大家談一下，
其中一件正在發生的事：
其中一件正在發生的事：
物質隨時在地球表面上移來移去，
00:51
Material get shuffled around
earth's surface all the time,
earth's surface all the time,
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其中一件在發生的大事，
00:53
and one of the big thing that happens
is material from high mountains
is material from high mountains
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就是來自高山的物質
會被侵蝕、運送、沉澱到大海中。
會被侵蝕、運送、沉澱到大海中。
00:57
gets eroded and transported
and deposited in the sea.
and deposited in the sea.
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00:59
And this process is ongoing all the time,
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這個過程一直在進行中，
01:01
and it has huge effects
on how the landscape works.
on how the landscape works.
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它對於地景有很大的影響。
01:03
So this example here in south India --
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這裡的例子是南印度，
01:05
we have some of the biggest
mountains in the world,
mountains in the world,
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這裡有一些世界最大的山。
01:08
and you can see in this satellite photo
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從衛星照片可以看見，
01:10
rivers transporting material
from those mountains out to the sea.
from those mountains out to the sea.
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河流將物質從那些山
向外運送到大海。
向外運送到大海。
01:14
You can think of these rivers
like bulldozers.
like bulldozers.
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你可以把這些河流想像成推土機，
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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基本上，它們是在
將這些山推移向大海。
將這些山推移向大海。
01:21
We'll give you guys an example here.
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我會給大家看一個例子。
01:23
So we zoom in a little bit.
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再放大一點來看。
01:24
I want to talk to you guys
specifically about a river.
specifically about a river.
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我想要跟你們談的是一條河。
01:27
We can see these beautiful patterns
that the rivers make
that the rivers make
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你們可以看見河流
在把物質推向大海的同時，
在把物質推向大海的同時，
01:29
as they're pushing material
down to the sea,
down to the sea,
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構成了很漂亮的圖案，
01:32
but these patterns aren't static.
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但這些圖案不是靜態不變的，
01:33
These rivers are wiggling
and jumping around quite a bit,
and jumping around quite a bit,
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這些河流挺會擺動和跳動的，
這對我們的生活有很大的影響。
01:36
and it can have big impacts on our lives.
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01:38
So an example of this
is this is the Kosi River.
is this is the Kosi River.
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這裡是一個例子：戈西河。
01:40
So the Kosi River
has this nice c-shaped pathway,
has this nice c-shaped pathway,
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戈西河有個很完好的 C 形路徑，
01:43
and it exits the big mountains of Nepal
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它從尼泊爾的大型山岳出海，
01:45
carrying with it a ton of material,
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帶著一大堆的物質，
01:48
a lot of sediments that's being
eroded from the high mountains,
eroded from the high mountains,
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很多從高山侵蝕下來的沉積物。
01:51
and it spreads out across India
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它佈及整個印度，
01:52
and moves this material.
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移動著這些物質。
01:54
So we're going to zoom in to this area
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我們再把這個區域放大，
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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我要告訴各位戈西河的狀況。
02:00
It's an example of how dynamic
these systems can be.
these systems can be.
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這個例子可以說明
這些系統有多動態。
這些系統有多動態。
02:02
So this is a satellite image
from August of 2008,
from August of 2008,
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這是一張衛星影像，
於 2008 年 8 月拍攝。
於 2008 年 8 月拍攝。
02:06
and this satellite image is colored
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這張衛星影像是彩色的，
02:08
so that vegetations or plants
show up as green
show up as green
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植被和植物會以綠色呈現，
02:10
and water shows up as blue.
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水會用藍色呈現。
02:12
So here again you can see
that c-shaped pathway
that c-shaped pathway
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你可以再次看到 C 形路徑，
02:15
that this river takes as it exits Nepal.
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這條河流從尼泊爾出海。
02:18
And now this is monsoon season.
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這時期是季風季，
02:20
August is monsoon season
in this region of the world,
in this region of the world,
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在這個區域，八月是季風季。
02:22
and anyone that lives near a river
is no stranger to flooding
is no stranger to flooding
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住在河流附近的人，
對於洪水絕對不陌生，
對於洪水絕對不陌生，
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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且肯定也很熟悉洪水
帶來的危險以及不便。
帶來的危險以及不便。
02:29
But something interesting
happened in 2008,
happened in 2008,
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但在 2008 年發生了
一件很有意思的事，
一件很有意思的事，
02:31
and this river moved in a way
that's very different.
that's very different.
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這條河流的移動方式變得非常不同，
02:34
It flooded in a way that's very
different than it normally does.
different than it normally does.
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它泛濫的方式也和平時非常不同。
02:37
So the Kosi River is flowing down here,
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戈西河在這裡向下流，
02:40
but sometimes as these rivers
are bulldozing sediment,
are bulldozing sediment,
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但有時，當這些河流
在推動沉積物時，
在推動沉積物時，
02:43
they kind of get clogged,
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它們會像是塞住了。
02:44
and these clogs can
actually cause the rivers
actually cause the rivers
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這些堵塞會造成河流
02:46
to shift their course dramatically.
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顯著轉變它們的路線。
02:48
So this satellite image
is from just two weeks later.
is from just two weeks later.
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這張衛星影像是兩週後拍的，
02:51
Here's the previous pathway,
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這是先前的路徑，
02:53
that c-shaped pathway,
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C 形的路徑。
02:54
and you notice it's not blue anymore.
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你可以注意到，它不再是藍色的了。
02:56
But now what we have is this blue pathway
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現在我們多了這條藍色路徑，
02:58
that cuts down the middle
of the field of view here.
of the field of view here.
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從畫面的中間切下來。
03:01
What happened is
the Kosi River jumped its banks,
the Kosi River jumped its banks,
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發生的事是：
戈西河躍過了它的堤岸。
戈西河躍過了它的堤岸。
03:03
and for reference,
the scale bar here is 40 miles.
the scale bar here is 40 miles.
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供大家參考，這條比例尺的
長度是 40 英哩。
長度是 40 英哩。
03:06
This river moved
over 30 miles very abruptly.
over 30 miles very abruptly.
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這條河流非常突然地
移動了超過 30 英哩。
移動了超過 30 英哩。
03:10
So this river got clogged
and it jumped its banks.
and it jumped its banks.
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這條河流被堵塞，
接著躍過了它的堤岸。
接著躍過了它的堤岸。
03:13
Here's an image from about a week later,
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這是大約一週後的影像。
03:15
and you can see
these are the previous pathways,
these are the previous pathways,
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可以看見這些是先前的路徑，
03:18
and you can see this process
of river-jumping continues
of river-jumping continues
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且可以看見這個
河流跳躍的過程還在持續著，
河流跳躍的過程還在持續著，
03:20
as this river moves farther away
from its major course.
from its major course.
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這條河流離它的主河道越來越遠。
03:23
So you can imagine
in landscapes like this,
in landscapes like this,
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你可以想像，在這種河流
03:26
where rivers move around frequently,
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常會到處移動的地景中，
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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知道它們何時、在哪兒、
以及如何跳躍是非常重要的。
以及如何跳躍是非常重要的。
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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但這類過程也會在離家
更近的地方常常發生，
更近的地方常常發生，
03:37
So in the United States,
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在美國，
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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我們有密西西比河，
流過幾乎整個美國大陸，
流過幾乎整個美國大陸，
03:43
It pushes material
from the Rocky Mountains
from the Rocky Mountains
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它把物質從洛磯山脈，
03:45
and from the Great Plains.
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以及北美大平原推走。
03:47
It drains it and moves it
all the way across America
all the way across America
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它帶著物質，一路穿越美國，
03:50
and dumps it out in the Gulf of Mexico.
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然後將物質倒在墨西哥灣。
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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這是我們現今很熟悉的
密西西比河路線，
密西西比河路線，
03:56
but it didn't always flow
in this direction.
in this direction.
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但它之前並非都是流向這個方向的。
03:58
If we use the geologic record,
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如果我們使用地理記錄，
04:00
we can reconstruct
where it went in the past.
where it went in the past.
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我們可以重新建造出
它過去流過的路線。
它過去流過的路線。
04:04
So for example, this red area here
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比如，這裡的紅色區域
04:06
is where we know the Mississippi River
flowed and deposited material
flowed and deposited material
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是據我們所知在 4600 年前密西西比河
04:10
about 4,600 years ago.
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流過並將物質沉積的地方。
04:12
Then about 3,500 years ago it moved
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接著，約 3500 年前，它移動了，
04:14
to follow the course
outlined here in orange.
outlined here in orange.
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延著這裡用橘色標出的路線流動。
04:16
And it kept moving and it keeps moving.
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它不斷、不斷地移動。
04:18
So here's about 2,000 years ago,
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這是約 2000 年前、
04:20
a thousand years ago,
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1000 年前、
04:22
700 years ago.
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700 年前。
04:23
And it was only
as recently as 500 years ago
as recently as 500 years ago
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一直要到 500 年前
這麼近期的時候，
這麼近期的時候，
04:26
that it occupied the pathway
that we're familiar with today.
that we're familiar with today.
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它才移到了我們現今熟悉的路徑。
04:30
So these processes are really important,
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這些過程非常重要，
04:32
and especially here, this delta area,
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特別是這裡，這個三角區域，
04:34
where these river-jumping events
in the Mississippi
in the Mississippi
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在這裡，這些
密西西比河的跳躍事件
密西西比河的跳躍事件
04:38
are building land at the interface
of the land and the sea.
of the land and the sea.
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在土地和海洋的接介處建立了土地。
04:41
This is really valuable real estate,
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這是非常珍貴的不動產，
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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地球上有許多人口密度最高的
區域都是像這樣的三角洲。
區域都是像這樣的三角洲。
04:48
So understanding the dynamics
of these landscapes,
of these landscapes,
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所以，了解這些地景的動態、
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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它們如何形成、
以及它們未來會如何持續改變，
以及它們未來會如何持續改變，
04:54
is really important
for the people that live there.
for the people that live there.
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對於居住在那兒的人而言，
是非常重要的。
是非常重要的。
04:57
So rivers also wiggle.
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所以，河流也會曲行。
04:59
These are sort of bigger jumps
that we've been talking about.
that we've been talking about.
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這些是我們先前談到的大跳躍。
05:01
I want to show you guys
some river wiggles here.
some river wiggles here.
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我想讓大家看一些河流的曲行，
05:04
So we're going to fly down
to the Amazon River basin,
to the Amazon River basin,
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所以我們要飛去亞瑪遜河盆地，
05:06
and here again we have a big river system
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在這裡我們也有很大的河流系統，
05:08
that is draining and moving and plowing
material from the Andean Mountains,
material from the Andean Mountains,
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將物質從安地斯山脈取下，
05:13
transporting it across South America
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運輸到南美的另一端，
05:15
and dumping it out
into the Atlantic Ocean.
into the Atlantic Ocean.
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將它丟在大西洋中。
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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我們把這裡放大，
讓大家能看見這些彎曲的路徑。
讓大家能看見這些彎曲的路徑。
05:23
Again, they're really beautiful,
but again, they're not static.
but again, they're not static.
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同樣地，它們也很漂亮，
但也同樣地，它們不是靜態的。
但也同樣地，它們不是靜態的。
05:26
These rivers wiggle around.
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這些河流會到處曲行。
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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我們可以用
過去 30 年的衛星影像，
過去 30 年的衛星影像，
05:31
to actually monitor how these change.
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來監看這些改變。
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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花一點時間，看著這條河的彎曲處，
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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你會發現它並不會在同一處
停留很長的時間。
停留很長的時間。
05:41
It changes and evolves
and warps its pattern.
and warps its pattern.
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它會改變、會演化、
會扭曲它的路線。
會扭曲它的路線。
05:44
If you look in this area in particular,
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我們可以特別看一下這個區域，
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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請大家注意，河流的這裡
有一個像是迴圈的狀況，
有一個像是迴圈的狀況，
05:50
that gets completely cut off.
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是完全切割開來的。
05:51
It's almost like a whip cracking
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幾乎就像是鞭子猛擊過去，
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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在某個點把河流的路徑給打斷。
05:56
So just for reference, again,
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這比例尺同樣也是參考用，
05:58
in this location, that river
changed its course over four miles
changed its course over four miles
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在這個地方，河流路徑改變了 4 英哩，
06:02
over the course of a season or two.
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且只花了一到兩季的時間。
06:05
So the landscapes
that we live in on earth,
that we live in on earth,
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所以在地球上我們所居住的地景，
06:08
as this material
is being eroded from the mountains
is being eroded from the mountains
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隨著這些物質從山上被侵蝕下來
06:10
and transported to the sea,
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並運送到海洋，
06:11
are wiggling around all the time.
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隨時隨地都在移動。
它們無時無刻不在改變，
06:13
They're changing all the time,
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而我們必須要了解這些過程，
06:14
and we need to be able
to understand these processes
to understand these processes
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才能在這些地景中
以永續的方式生活下去。
以永續的方式生活下去。
06:17
so we can manage and live
sustainably on these landscapes.
sustainably on these landscapes.
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06:20
But it's hard to do
if the only information we have
if the only information we have
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但是，如果我們手上只有
關於現今地球表面
關於現今地球表面
06:23
is what's going on today
at earth's surface.
at earth's surface.
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發生什麼狀況的資訊，
就很難做到。
就很難做到。
06:25
Right? We don't have
a lot of observations.
a lot of observations.
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對吧？我們並沒有很多觀察資料。
06:27
We only have 30 years' worth
of satellite photos, for example.
of satellite photos, for example.
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比如，我們的衛星照片
就只有近 30 年的。
就只有近 30 年的。
06:32
We need more observations
to understand these processes more.
to understand these processes more.
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我們需要更多的觀察
才能更了解這些過程。
才能更了解這些過程。
06:35
And additionally, we need to know
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此外，我們得要知道
06:37
how these landscapes are going
to respond to changing climate
to respond to changing climate
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這些地景對於氣候變遷、
06:40
and to changing land use
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以及因我們持續佔領和改變地球表面
而造成的土地使用改變，
而造成的土地使用改變，
06:41
as we continue to occupy
and modify earth's surface.
and modify earth's surface.
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將會有什麼反應。
06:45
So this is where the rocks come in.
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這就是要來談岩石的地方了。
06:47
So as rivers flow,
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隨著河流流動，
06:50
as they're bulldozing material
from the mountains to the sea,
from the mountains to the sea,
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隨著它們把物質從山上推到海中，
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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有些沙、泥、石頭會卡在地上，
06:56
And that stuff that gets stuck
in the ground gets buried,
in the ground gets buried,
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卡在地上的這些東西就會被埋掉，
06:59
and through time, we get
big, thick accumulations of sediments
big, thick accumulations of sediments
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隨著時間，會讓沉積物更多更厚，
07:03
that eventually turn into rocks.
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最終變成岩石。
07:05
What this means is that we can
go to places like this,
go to places like this,
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這意味著，我們可以到
圖上的這種地方，
圖上的這種地方，
07:07
where we see big, thick stacks
of sedimentary rocks,
of sedimentary rocks,
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在這裡會看到厚實的
層層大型沉積岩，
層層大型沉積岩，
07:10
and go back in time
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再回到過去，
07:12
and see what the landscapes
looked like in the past.
looked like in the past.
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看看過去的地景是什麼樣子的。
07:14
We can do this to help reconstruct
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我們可以這樣做，來重新建造
07:16
and understand
how earth landscapes evolve.
how earth landscapes evolve.
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並了解地球地景是如何演化的。
07:22
This is pretty convenient, too,
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這也挺方便的，
07:23
because the earth has had
sort of an epic history. Right?
sort of an epic history. Right?
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因為地球的歷史還蠻壯觀的，對吧？
07:26
So this video here
is a reconstruction of paleogeography
is a reconstruction of paleogeography
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這段影片是古地理學的重建，
07:31
for just the first
600 million years of earth's history.
600 million years of earth's history.
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它僅呈現了地球歷史的前六億年。
07:35
So just a little bit of time here.
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只是一點點時間而已。
07:37
So as the plates move around,
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隨著板塊移動，
07:40
we know climate has changed,
sea level has changed,
sea level has changed,
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我們知道氣候改變了、
海平面改變了，
海平面改變了，
07:43
we have a lot of different
types of landscapes
types of landscapes
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我們有許多不同的地景，
07:46
and different types of environments
that we can go back --
that we can go back --
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及不同型的環境，
如果我們有時光機，
如果我們有時光機，
07:49
if we have a time machine --
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就可以回到過去，
07:51
we can go back and look at,
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我們可以回去看看，
07:52
and we do indeed have a time machine
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且我們的確有時光機，
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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因為我們可以去看
這些時代所沉積的岩石。
這些時代所沉積的岩石。
07:57
So I'm going to give you
an example of this
an example of this
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讓我來舉個例子，
07:59
and take you to a special
time in earth's past.
time in earth's past.
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帶大家回到地球
過去的一個特殊時點，
過去的一個特殊時點，
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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大約五千五百萬年前，
08:05
and what happened was
a whole bunch of carbon dioxide
a whole bunch of carbon dioxide
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當時的狀況是有大量的二氧化碳
被排放到地球的大氣層，
08:07
was released into earth's atmosphere,
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造成了快速且極端的全球暖化事件。
08:09
and it caused a rapid
and pretty extreme global warming event.
and pretty extreme global warming event.
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08:13
And when I say warm, I mean pretty warm,
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我說的暖化，是非常暖的暖化，
08:15
that there were things
like crocodiles and palm trees
like crocodiles and palm trees
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當時甚至會有鱷魚和棕櫚樹，
08:18
as far north as Canada
and as far south as Patagonia.
and as far south as Patagonia.
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出現在很北方如加拿大、
以及很南方如巴塔哥尼亞的地方。
以及很南方如巴塔哥尼亞的地方。
08:22
So this was a pretty warm time
and it happened really abruptly.
and it happened really abruptly.
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這是相當溫暖的時期，
且發生的非常突然。
且發生的非常突然。
08:25
So what we can do
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我們能做的是，
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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回到過去，找出
在這個時期沉積的岩石，
在這個時期沉積的岩石，
08:29
and reconstruct how the landscape changed
in response to this warming event.
in response to this warming event.
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然後重建出因應這暖化事件
而改變的地景。
而改變的地景。
08:33
So here, yay, rocks.
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所以，這裡是──太棒了，岩石。
08:35
(Laughter)
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（笑聲）
08:37
Here's a pile of rocks.
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這裡有一堆岩石。
08:39
This yellow blob here,
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這裡黃色的部份，
08:41
this is actually a fossil river,
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其實是古河流，
08:43
so just like this cartoon I showed,
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就像我剛剛展示的連環圖，
08:44
these are deposits that were
laid down 55 million years ago.
laid down 55 million years ago.
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這些沉積是五千五百萬年前發生的。
08:48
As geologists, we can go
and look at these up close
and look at these up close
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身為地質學家，
我們可以更近距離去看，
我們可以更近距離去看，
08:51
and reconstruct the landscape.
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並重建出地景來。
08:53
So here's another example.
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這裡還有另一個例子。
08:54
The yellow blob here is a fossil river.
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這裡的黃色部份是古河流。
08:57
Here's another one above it.
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上面還有一條。
08:58
We can go and look in detail
and make measurements and observations,
and make measurements and observations,
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我們可以更細部去看，
並做些測量與觀察，
並做些測量與觀察，
09:02
and we can measure features.
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我們可以去測量特徵。
09:03
For example, the features
I just highlighted there
I just highlighted there
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比如，我剛剛強調出來的特徵，
09:05
tell us that this particular river
was probably about three feet deep.
was probably about three feet deep.
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告訴我們這條河流可能有三英呎深。
09:09
You could wade
across this cute little stream
across this cute little stream
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如果五千五百萬年前你在這裡行走，
09:11
if you were walking around
55 million years ago.
55 million years ago.
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你可以徒步跋涉通過這條小溪。
09:14
The reddish stuff that's above
and below those channels,
and below those channels,
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這些河床上面和下面的紅色部份，
09:17
those are ancient soil deposits.
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是古時的土壤沉積。
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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看著這些，我們就可以知道
在這地景上住著或生長著什麼，
在這地景上住著或生長著什麼，
09:23
and to understand how these rivers
were interacting with their floodplains.
were interacting with their floodplains.
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並了解這些河流如何
與它們的泛濫平原互動。
與它們的泛濫平原互動。
09:27
So we can look in detail
and reconstruct with some specificity
and reconstruct with some specificity
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我們可以去看細節，
並更明確地重建出
並更明確地重建出
09:32
how these rivers flowed
and what the landscapes looked like.
and what the landscapes looked like.
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這些河流如何流動、
以及當時地景是什麼樣子。
以及當時地景是什麼樣子。
09:34
So when we do this
for this particular place
for this particular place
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當我們針對這個時期的特定地點
09:38
at this time,
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這麼做時，
09:39
if we look what happened
before this abrupt warming event,
before this abrupt warming event,
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如果我們去探究在突發暖化事件
之前發生了什麼事，
之前發生了什麼事，
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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河流有點像是從
山上切下一條路通往海洋，
山上切下一條路通往海洋，
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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看起來會有點像是我先前展示的
亞瑪遜盆地的狀況。
亞瑪遜盆地的狀況。
09:50
But right at the onset
of this climate change event,
of this climate change event,
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但就在這氣候變遷甚至開始時，
09:53
the rivers change dramatically.
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河流有了戲劇性的改變，
09:55
All of a sudden they got much broader,
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突然間它們變寬許多，
09:57
and they started to slide back and forth
across the landscape more readily.
across the landscape more readily.
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且它們開始更快速地
在地景上前後滑動。
在地景上前後滑動。
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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最終，河流回復到類似
10:05
to what they would have looked like
before this climate event,
before this climate event,
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氣候事件發生之前的狀態，
10:09
but it took a long, long time.
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但這花了非常長的時間。
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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我們可以回到地球的過去
並做這種重建，
並做這種重建，
10:16
and understand how
earth's landscape has changed
earth's landscape has changed
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以了解地球的地景如何改變，
10:18
in response to a climate event like this
or a land use event.
or a land use event.
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來因應像這樣的氣候事件
或土地使用事件。
或土地使用事件。
10:22
So some of the ways that rivers change
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河流改變的方式、
10:24
or the reasons that rivers change
their pattern and their movements
their pattern and their movements
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或河流改變的原因以及移動，
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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要歸因於像是當氣候變熱時
有額外的水落在
有額外的水落在
10:33
when climate is hotter,
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地球表面的這類狀況。
10:35
we can move more sediment
and erode more sediment,
and erode more sediment,
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更多沉積物被搬移、
更多沉積物被侵蝕，
更多沉積物被侵蝕，
10:37
and that changes how rivers behave.
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就會改變河流的行為。
10:40
So ultimately,
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所以，最終，
10:42
as long as earth's surface is our home,
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只要地球表面還是我們的家園，
10:45
we need to carefully manage
the resources and risks
the resources and risks
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我們就需要小心管理與居住在
10:48
associated with living
in dynamic environments.
in dynamic environments.
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動態環境相關的資源與風險。
10:51
And I think the only way
we can really do that sustainably
we can really do that sustainably
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我認為，要做到這一點的
永續方法只有一個，
永續方法只有一個，
10:55
is if we include information
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就是我們要能納入
10:58
about how landscapes evolved
and behaved in earth's past.
and behaved in earth's past.
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關於地景如何演化
以及過去行為的資訊。
以及過去行為的資訊。
11:02
Thank you.
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謝謝大家。
11:03
(Applause)
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（鼓掌）
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