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The death of an island
is a common occurrence on our Earth.

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And today ICESat-2, our satellite lidar

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altimetry system, can see
and watch these spectacular places.

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It's almost spooky
because islands are part of the glimmers

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of how the Earth works
in the giant oceanic environment.

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So let's take a look
at one of these island systems in a remote

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part of the Southwest Pacific,
known as the Kingdom of Tonga,

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and this island archipelago is special
because it has lots of volcanoes.

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Recently, ICESat-2 was able to produce
topography of one of these islands.

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A recently formed one known as Hunga
Tonga Hunga Ha'apai

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in the Southwest Pacific
and this island, only a couple

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hundred hectares in extent, was burst
from the shallow waters

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oceans of this part of the Pacific
about six years ago.

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It constructed a 120-meter high volcano
and that volcanic island's

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been crumbling against the barrage
of forces of the ocean

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and tropical cyclones
over the last six years.

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ICESat-2 was able to see that island
with the finest scale

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precision of satellite laser
altimetry possible

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and show us the structure of the island
as it's crumbling.

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What ICESat-2 shows us the shallow crater
lake that formed as the volcano

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was erupting and then filled with ocean
water is only ten or 15 meters deep.

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It reflects what might be the volcanic
vent system that led to the formation

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of this special island.

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Now, other islands in the Tonga system

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haven't survived as well, and one erupted
beautifully in the fall of 2019.

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And that island, which is named

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Late'iki, formed a new island
just several meters above sea level

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that was then witnessed by ICESat-2
a few months after the island washed away.

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And what's left are the remnant shoals
of a region that's very active.

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The tip of a three kilometer,
10.000 foot undersea volcano

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that pops its head above
and below the waves every decade or two.

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The death of islands is like the ghostlike
relics of what the Earth once was.

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And we know there's thousands
of these things on the ocean

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and the sea floor, most of which
don't poke their heads above the water.