Name: 美到不科學！有些湖為什麼可以「藍」成這樣？ (What Causes the Bright Turquoise Color of Glacial Lakes? GEO GIRL)
Uploaded: 2026-01-07T21:01:20.000Z
Duration: 3 min 46 s

The water in this lake is so turquoise, it almost looks fake, but it is in fact real.

這座湖的湖水藍綠得不可思議，看起來幾乎像是假的，但它其實是真實存在的。

Typically, lakes are greenish brown or even dark blue.

一般來說，湖泊的顏色多半是偏綠褐色，甚至是深藍色。

But this lake, Garibaldi Lake in British Columbia, is certainly not a typical lake color.

但這座湖——位於加拿大卑詩省的加里波第湖——顯然不是典型的湖水顏色。

So what is causing this bright turquoise color?

那麼，是什麼造成了這種明亮的藍綠色呢？

Well, it's not that there's some strange mineral dying the lake,

其實並不是因為湖裡有什麼奇怪的礦物在染色，

it's actually a combination of geology and physics that causes this color.

而是地質作用與物理現象共同造成了這種顏色。

The the secret lies in the glaciers you see feeding into the lake.

關鍵就藏在你看到流入湖中的那些冰河裡。

When glaciers grind down mountains, they don't just carve valleys,

當冰河磨蝕山體時，不只是雕刻出山谷，

they also pulverize rock into very fine powder called glacial flour.

同時也會把岩石磨成極細的粉末，稱為「冰河粉」。

These tiny particles are smaller than sand or silt, often just microns across.

這些微小顆粒比沙子或粉砂還細，大小往往只有幾微米。

And streams carry this glacial flower into Garibaldi Lake

隨著冰河融水向下流動，溪流會把這些冰河粉帶進加里波第湖，

as meltwater flows down from the glaciers up in the taller mountains surrounding the lake.

這些融水來自環繞湖泊、較高山區的冰河。

But here's the key: Those particles don't settle quickly.

但重點來了：這些顆粒不會很快沉澱。

Instead, they stay suspended in the water column, scattering light in a very specific way.

相反地，它們會懸浮在水體中，以一種非常特定的方式散射光線。

When sunlight hits the lake, the suspended glacial flour scatters the shorter wavelengths of visible light, the blues and the greens, back toward our eyes,

當陽光照射湖面時，懸浮的冰河粉會將可見光中較短波長的藍光與綠光散射回我們的眼睛，

while the longer wavelengths like reds and yellows, are absorbed.

而較長波長的紅光與黃光則會被吸收。

That's why instead of muddy mucky water, we see this incredible turquoise glow.

這就是為什麼我們看到的不是混濁骯髒的湖水，而是這種驚人的藍綠色光澤。

And fun fact, this is the same effect that causes the color of many lakes across glaciated mountain,

有趣的是，這也是許多冰河地形湖泊呈現顏色的原因，

like those in the Canadian Rockies, Alaska and even some in Iceland.

像是加拿大洛磯山脈、阿拉斯加，甚至冰島的一些湖泊。

But importantly, not all glacial lakes are bright turquoise like this.

但重點是，並不是所有冰河湖都會呈現如此鮮豔的藍綠色。

And it turns out, it's because the type or composition of the rock that gets grinded into the flour matters.

原因就在於，被磨成冰河粉的岩石種類與成分不同。

Silica-rich felsic rocks like granite and granitic gneiss produce light colored fine quartz and feldspar-rich flour,

富含二氧化矽的長英質岩石，例如花崗岩與花崗片麻岩，會產生顏色較淺、富含石英與長石的冰河粉，

which reflects light very effectively, resulting in bright turquoise to milky blue lakes.

這類顆粒能有效反射光線，使湖水呈現明亮的藍綠色到乳藍色。

Whereas those with lower silica content, like intermediate to mafic volcanic andesite and basalt,

相較之下，二氧化矽含量較低的中性至鎂鐵質火山岩，例如安山岩與玄武岩，

tend to make darker iron and magnesium-rich flour, which absorbs more light,

會產生含鐵與鎂較多、顏色較深的冰河粉，吸收更多光線，

making lakes that look greener, grayish or duller blue, depending on concentration.

因此湖水看起來會偏綠、偏灰，或較暗的藍色，取決於濃度。

And lastly, carbonate rocks like limestone or dolostone yield whitish flour.

最後，像石灰岩或白雲岩這類碳酸鹽岩石，會產生偏白色的冰河粉。

Sometimes producing chalky aqua or jade green tones.

有時會形成粉白色的湖水，呈現淺藍綠或翡翠綠的色調。

So because the glaciers feeding Garibaldi Lake grind up both felsic rocks like granite from the coast plutonic complex that I talked about a couple videos ago, and

由於供給加里波第湖的冰河，同時磨碎了我在前幾支影片提過的海岸深成岩體中的長英質岩石（如花崗岩），以及

intermediate to mafic volcanic rocks like basalts and andesites from Mount Price, Black Tusk and other lava flows,

來自普萊斯山、黑牙峰及其他熔岩流的中性至鎂鐵質火山岩，

this results in a very quartz and feldspar-rich glacial flower with some more silica-poor volcanic materials,

這使得湖中冰河粉富含石英與長石，同時也混合了一些矽含量較低的火山物質，

which are light enough to strongly scatter blue and green light, but

這些顆粒既足夠輕，能強烈散射藍光與綠光，

also fine enough to stay suspended for long periods of time.

又足夠細小，可以長時間懸浮在水中。

And this leads to Garibaldi's vivid but not opaque turquoise color.

這正是加里波第湖呈現鮮明卻不混濁藍綠色的原因。

這種顏色仰賴於仍然活躍的冰河。

As climate warms and Garibaldi's glaciers retreat,

隨著氣候變暖，加里波第的冰河正在退縮，

they'll produce less meltwater and less glacial flour.

它們產生的融水與冰河粉也會隨之減少。

And over the centuries, as the glaciers vanish, Garibaldi Lake's iconic turquoise may fade into a more ordinary blue.

在未來幾個世紀中，當冰河消失後，加里波第湖標誌性的藍綠色可能會逐漸退去，變成較普通的藍色。

So come see this beautiful lake before its gorgeous blue color fades away.

所以趁這片迷人的藍色還存在時，來親眼看看這座美麗的湖吧。

But keep in mind the hike up to Garibaldi Lake is 18km and straight uphill, so be prepared.

但請記住，前往加里波第湖的健行路線全長 18 公里，而且幾乎一路上坡，請務必做好準備。

And be sure to check out the others I made recently about the geology of this area.

也別忘了看看我最近做的其他關於這一帶地質的影片。

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美到不科學！有些湖為什麼可以「藍」成這樣？ (What Causes the Bright Turquoise Color of Glacial Lakes? GEO GIRL)

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