The earth is pretty awesome.

好，我們先來看一下地球的圖片。

I'm a geologist, so I get pretty psyched about this,

地球是很了不起的。

but the earth is great.

我是地質學家， 所以我對這點十分亢奮。

It's powerful, it's dynamic, it's constantly changing.

但地球很棒，

It's a pretty exciting place to live.

它很強大、它是動態的、 它不斷在改變，

But I want to share with you guys today my perspective as a geologist

住在地球是很讓人興奮的。

in how understanding earth's past

但我今天想和大家分享的， 是我身為地質學家的觀點，

can help inform and guide decisions that we make today

來談談了解地球的過去，

about how to sustainably live on earth's surface.

如何能提供我們資訊和導引，

So there's a lot of exciting things that go on on the surface of the earth.

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。

If we zoom in here a little bit,

在地球表面上， 有許多讓人興奮的事物在發生。

I want to talk to you guys a little bit about one of the things that happens.

如果我們把這裡放大一點，

Material get shuffled around earth's surface all the time,

我想要跟大家談一下， 其中一件正在發生的事：

and one of the big thing that happens is material from high mountains

物質隨時在地球表面上移來移去，

gets eroded and transported and deposited in the sea.

其中一件在發生的大事，

And this process is ongoing all the time,

就是來自高山的物質 會被侵蝕、運送、沉澱到大海中。

and it has huge effects on how the landscape works.

這個過程一直在進行中，

So this example here in south India --

它對於地景有很大的影響。

we have some of the biggest mountains in the world,

這裡的例子是南印度，

and you can see in this satellite photo

這裡有一些世界最大的山。

rivers transporting material from those mountains out to the sea.

從衛星照片可以看見，

You can think of these rivers like bulldozers.

河流將物質從那些山 向外運送到大海。

They're basically taking these mountains and pushing them down towards the sea.

你可以把這些河流想像成推土機，

We'll give you guys an example here.

基本上，它們是在 將這些山推移向大海。

So we zoom in a little bit.

我會給大家看一個例子。

I want to talk to you guys specifically about a river.

再放大一點來看。

We can see these beautiful patterns that the rivers make

我想要跟你們談的是一條河。

as they're pushing material down to the sea,

你們可以看見河流 在把物質推向大海的同時，

but these patterns aren't static.

構成了很漂亮的圖案，

These rivers are wiggling and jumping around quite a bit,

但這些圖案不是靜態不變的，

and it can have big impacts on our lives.

這些河流挺會擺動和跳動的，

So an example of this is this is the Kosi River.

這對我們的生活有很大的影響。

So the Kosi River has this nice c-shaped pathway,

這裡是一個例子：戈西河。

and it exits the big mountains of Nepal

戈西河有個很完好的 C 形路徑，

carrying with it a ton of material,

它從尼泊爾的大型山岳出海，

a lot of sediments that's being eroded from the high mountains,

帶著一大堆的物質，

and it spreads out across India

很多從高山侵蝕下來的沉積物。

and moves this material.

它佈及整個印度，

So we're going to zoom in to this area

移動著這些物質。

and I'm going to tell you a little bit about what happened with the Kosi.

我們再把這個區域放大，

It's an example of how dynamic these systems can be.

我要告訴各位戈西河的狀況。

So this is a satellite image from August of 2008,

這個例子可以說明 這些系統有多動態。

and this satellite image is colored

這是一張衛星影像， 於 2008 年 8 月拍攝。

so that vegetations or plants show up as green

這張衛星影像是彩色的，

and water shows up as blue.

植被和植物會以綠色呈現，

So here again you can see that c-shaped pathway

水會用藍色呈現。

that this river takes as it exits Nepal.

你可以再次看到 C 形路徑，

And now this is monsoon season.

這條河流從尼泊爾出海。

August is monsoon season in this region of the world,

這時期是季風季，

and anyone that lives near a river is no stranger to flooding

在這個區域，八月是季風季。

and the hazards and inconveniences at minimum that are associated with that.

住在河流附近的人， 對於洪水絕對不陌生，

But something interesting happened in 2008,

且肯定也很熟悉洪水 帶來的危險以及不便。

and this river moved in a way that's very different.

但在 2008 年發生了 一件很有意思的事，

It flooded in a way that's very different than it normally does.

這條河流的移動方式變得非常不同，

So the Kosi River is flowing down here,

它泛濫的方式也和平時非常不同。

but sometimes as these rivers are bulldozing sediment,

戈西河在這裡向下流，

they kind of get clogged,

但有時，當這些河流 在推動沉積物時，

and these clogs can actually cause the rivers

它們會像是塞住了。

to shift their course dramatically.

這些堵塞會造成河流

So this satellite image is from just two weeks later.

顯著轉變它們的路線。

Here's the previous pathway,

這張衛星影像是兩週後拍的，

that c-shaped pathway,

這是先前的路徑，

and you notice it's not blue anymore.

C 形的路徑。

But now what we have is this blue pathway

你可以注意到，它不再是藍色的了。

that cuts down the middle of the field of view here.

現在我們多了這條藍色路徑，

What happened is the Kosi River jumped its banks,

從畫面的中間切下來。

and for reference, the scale bar here is 40 miles.

發生的事是： 戈西河躍過了它的堤岸。

This river moved over 30 miles very abruptly.

供大家參考，這條比例尺的 長度是 40 英哩。

So this river got clogged and it jumped its banks.

這條河流非常突然地 移動了超過 30 英哩。

Here's an image from about a week later,

這條河流被堵塞， 接著躍過了它的堤岸。

and you can see these are the previous pathways,

這是大約一週後的影像。

and you can see this process of river-jumping continues

可以看見這些是先前的路徑，

as this river moves farther away from its major course.

且可以看見這個 河流跳躍的過程還在持續著，

So you can imagine in landscapes like this,

這條河流離它的主河道越來越遠。

where rivers move around frequently,

你可以想像，在這種河流

it's really important to understand when, where and how they're going to jump.

常會到處移動的地景中，

But these kinds of processes also happen a lot closer to home as well.

知道它們何時、在哪兒、 以及如何跳躍是非常重要的。

So in the United States,

但這類過程也會在離家 更近的地方常常發生，

we have the Mississippi River that drains most of the continental US.

在美國，

It pushes material from the Rocky Mountains

我們有密西西比河， 流過幾乎整個美國大陸，

and from the Great Plains.

它把物質從洛磯山脈，

It drains it and moves it all the way across America

以及北美大平原推走。

and dumps it out in the Gulf of Mexico.

它帶著物質，一路穿越美國，

So this is the course of the Mississippi that we're familiar with today,

然後將物質倒在墨西哥灣。

but it didn't always flow in this direction.

這是我們現今很熟悉的 密西西比河路線，

If we use the geologic record,

但它之前並非都是流向這個方向的。

we can reconstruct where it went in the past.

如果我們使用地理記錄，

So for example, this red area here

我們可以重新建造出 它過去流過的路線。

is where we know the Mississippi River flowed and deposited material

比如，這裡的紅色區域

about 4,600 years ago.

是據我們所知在 4600 年前密西西比河

Then about 3,500 years ago it moved

流過並將物質沉積的地方。

to follow the course outlined here in orange.

接著，約 3500 年前，它移動了，

And it kept moving and it keeps moving.

延著這裡用橘色標出的路線流動。

So here's about 2,000 years ago,

它不斷、不斷地移動。

a thousand years ago,

這是約 2000 年前、

700 years ago.

1000 年前、

And it was only as recently as 500 years ago

700 年前。

that it occupied the pathway that we're familiar with today.

一直要到 500 年前 這麼近期的時候，

So these processes are really important,

它才移到了我們現今熟悉的路徑。

and especially here, this delta area,

這些過程非常重要，

where these river-jumping events in the Mississippi

特別是這裡，這個三角區域，

are building land at the interface of the land and the sea.

在這裡，這些 密西西比河的跳躍事件

This is really valuable real estate,

在土地和海洋的接介處建立了土地。

and deltas like this are some of the most densely populated areas on our planet.

這是非常珍貴的不動產，

So understanding the dynamics of these landscapes,

地球上有許多人口密度最高的 區域都是像這樣的三角洲。

how they formed and how they will continue to change in the future

所以，了解這些地景的動態、

is really important for the people that live there.

它們如何形成、 以及它們未來會如何持續改變，

So rivers also wiggle.

對於居住在那兒的人而言， 是非常重要的。

These are sort of bigger jumps that we've been talking about.

所以，河流也會曲行。

I want to show you guys some river wiggles here.

這些是我們先前談到的大跳躍。

So we're going to fly down to the Amazon River basin,

我想讓大家看一些河流的曲行，

and here again we have a big river system

所以我們要飛去亞瑪遜河盆地，

that is draining and moving and plowing material from the Andean Mountains,

在這裡我們也有很大的河流系統，

transporting it across South America

將物質從安地斯山脈取下，

and dumping it out into the Atlantic Ocean.

運輸到南美的另一端，

So if we zoom in here, you guys can see these nice, curvy river pathways.

將它丟在大西洋中。

Again, they're really beautiful, but again, they're not static.

我們把這裡放大， 讓大家能看見這些彎曲的路徑。

These rivers wiggle around.

同樣地，它們也很漂亮， 但也同樣地，它們不是靜態的。

We can use satellite imagery over the last 30 or so years

這些河流會到處曲行。

to actually monitor how these change.

我們可以用 過去 30 年的衛星影像，

So take a minute and just watch any bend or curve in this river,

來監看這些改變。

and you'll see it doesn't stay in the same place for very long.

花一點時間，看著這條河的彎曲處，

It changes and evolves and warps its pattern.

你會發現它並不會在同一處 停留很長的時間。

If you look in this area in particular,

它會改變、會演化、 會扭曲它的路線。

I want you guys to notice there's a sort of a loop in the river

我們可以特別看一下這個區域，

that gets completely cut off.

請大家注意，河流的這裡 有一個像是迴圈的狀況，

It's almost like a whip cracking

是完全切割開來的。

and snaps off the pathway of the river at a certain spot.

幾乎就像是鞭子猛擊過去，

So just for reference, again,

在某個點把河流的路徑給打斷。

in this location, that river changed its course over four miles

這比例尺同樣也是參考用，

over the course of a season or two.

在這個地方，河流路徑改變了 4 英哩，

So the landscapes that we live in on earth,

且只花了一到兩季的時間。

as this material is being eroded from the mountains

所以在地球上我們所居住的地景，

and transported to the sea,

隨著這些物質從山上被侵蝕下來

are wiggling around all the time.

並運送到海洋，

They're changing all the time,

隨時隨地都在移動。

and we need to be able to understand these processes

它們無時無刻不在改變，

so we can manage and live sustainably on these landscapes.

而我們必須要了解這些過程，

But it's hard to do if the only information we have

才能在這些地景中 以永續的方式生活下去。

is what's going on today at earth's surface.

但是，如果我們手上只有 關於現今地球表面

Right? We don't have a lot of observations.

發生什麼狀況的資訊， 就很難做到。

We only have 30 years' worth of satellite photos, for example.

對吧？我們並沒有很多觀察資料。

We need more observations to understand these processes more.

比如，我們的衛星照片 就只有近 30 年的。

And additionally, we need to know

我們需要更多的觀察 才能更了解這些過程。

how these landscapes are going to respond to changing climate

此外，我們得要知道

and to changing land use

這些地景對於氣候變遷、

as we continue to occupy and modify earth's surface.

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，

So this is where the rocks come in.

將會有什麼反應。

So as rivers flow,

這就是要來談岩石的地方了。

as they're bulldozing material from the mountains to the sea,

隨著河流流動，

sometimes bits of sand and clay and rock get stuck in the ground.

隨著它們把物質從山上推到海中，

And that stuff that gets stuck in the ground gets buried,

有些沙、泥、石頭會卡在地上，

and through time, we get big, thick accumulations of sediments

卡在地上的這些東西就會被埋掉，

that eventually turn into rocks.

隨著時間，會讓沉積物更多更厚，

What this means is that we can go to places like this,

最終變成岩石。

where we see big, thick stacks of sedimentary rocks,

這意味著，我們可以到 圖上的這種地方，

and go back in time

在這裡會看到厚實的 層層大型沉積岩，

and see what the landscapes looked like in the past.

再回到過去，

We can do this to help reconstruct

看看過去的地景是什麼樣子的。

and understand how earth landscapes evolve.

我們可以這樣做，來重新建造

This is pretty convenient, too,

並了解地球地景是如何演化的。

because the earth has had sort of an epic history. Right?

這也挺方便的，

So this video here is a reconstruction of paleogeography

因為地球的歷史還蠻壯觀的，對吧？

for just the first 600 million years of earth's history.

這段影片是古地理學的重建，

So just a little bit of time here.

它僅呈現了地球歷史的前六億年。

So as the plates move around,

只是一點點時間而已。

we know climate has changed, sea level has changed,

隨著板塊移動，

we have a lot of different types of landscapes

我們知道氣候改變了、 海平面改變了，

and different types of environments that we can go back --

我們有許多不同的地景，

if we have a time machine --

及不同型的環境， 如果我們有時光機，

we can go back and look at,

就可以回到過去，

and we do indeed have a time machine

我們可以回去看看，

because we can look at the rocks that were deposited at these times.

且我們的確有時光機，

So I'm going to give you an example of this

因為我們可以去看 這些時代所沉積的岩石。

and take you to a special time in earth's past.

讓我來舉個例子，

About 55 million years ago, there was a really abrupt warming event,

帶大家回到地球 過去的一個特殊時點，

and what happened was a whole bunch of carbon dioxide

大約五千五百萬年前，

was released into earth's atmosphere,

當時的狀況是有大量的二氧化碳

and it caused a rapid and pretty extreme global warming event.

被排放到地球的大氣層，

And when I say warm, I mean pretty warm,

造成了快速且極端的全球暖化事件。

that there were things like crocodiles and palm trees

我說的暖化，是非常暖的暖化，

as far north as Canada and as far south as Patagonia.

當時甚至會有鱷魚和棕櫚樹，

So this was a pretty warm time and it happened really abruptly.

出現在很北方如加拿大、 以及很南方如巴塔哥尼亞的地方。

So what we can do

這是相當溫暖的時期， 且發生的非常突然。

is we can go back and find rocks that were deposited at this time

我們能做的是，

and reconstruct how the landscape changed in response to this warming event.

回到過去，找出 在這個時期沉積的岩石，

So here, yay, rocks.

然後重建出因應這暖化事件 而改變的地景。

(Laughter)

所以，這裡是──太棒了，岩石。

Here's a pile of rocks.

（笑聲）

This yellow blob here,

這裡有一堆岩石。

this is actually a fossil river,

這裡黃色的部份，

so just like this cartoon I showed,

其實是古河流，

these are deposits that were laid down 55 million years ago.

就像我剛剛展示的連環圖，

As geologists, we can go and look at these up close

這些沉積是五千五百萬年前發生的。

and reconstruct the landscape.

身為地質學家， 我們可以更近距離去看，

So here's another example.

並重建出地景來。

The yellow blob here is a fossil river.

這裡還有另一個例子。

Here's another one above it.

這裡的黃色部份是古河流。

We can go and look in detail and make measurements and observations,

上面還有一條。

and we can measure features.

我們可以更細部去看， 並做些測量與觀察，

For example, the features I just highlighted there

我們可以去測量特徵。

tell us that this particular river was probably about three feet deep.

比如，我剛剛強調出來的特徵，

You could wade across this cute little stream

告訴我們這條河流可能有三英呎深。

if you were walking around 55 million years ago.

如果五千五百萬年前你在這裡行走，

The reddish stuff that's above and below those channels,

你可以徒步跋涉通過這條小溪。

those are ancient soil deposits.

這些河床上面和下面的紅色部份，

So we can look at those to tell us what lived and grew on the landscape

是古時的土壤沉積。

and to understand how these rivers were interacting with their floodplains.

看著這些，我們就可以知道 在這地景上住著或生長著什麼，

So we can look in detail and reconstruct with some specificity

並了解這些河流如何 與它們的泛濫平原互動。

how these rivers flowed and what the landscapes looked like.

我們可以去看細節， 並更明確地重建出

So when we do this for this particular place

這些河流如何流動、 以及當時地景是什麼樣子。

at this time,

當我們針對這個時期的特定地點

if we look what happened before this abrupt warming event,

這麼做時，

the rivers kind of carved their way down from the mountains to the sea,

如果我們去探究在突發暖化事件 之前發生了什麼事，

and they looked maybe similar to what I showed you in the Amazon River basin.

河流有點像是從 山上切下一條路通往海洋，

But right at the onset of this climate change event,

看起來會有點像是我先前展示的 亞瑪遜盆地的狀況。

the rivers change dramatically.

但就在這氣候變遷甚至開始時，

All of a sudden they got much broader,

河流有了戲劇性的改變，

and they started to slide back and forth across the landscape more readily.

突然間它們變寬許多，

Eventually, the rivers reverted back to a state that was more similar

且它們開始更快速地 在地景上前後滑動。

to what they would have looked like before this climate event,

最終，河流回復到類似

but it took a long, long time.