Page 80 - Super Earth Encyclopedia

VOLCANIC HOTSPOT

HAWAIIAN ISLAND CHAIN

The active volcanoes of Hawaii are part of a chain of islands and Trail of volcanoes
submerged seamounts that extends across the Pacific Ocean to Russia. The Hawaiian islands have been created by
Each of its volcanoes has erupted over the same hotspot beneath a plume of heat rising through Earth’s deep
mantle. This heat makes the ocean-floor rock
the moving ocean floor. The plate movement carries the islands melt and form gigantic volcanoes. As the
northwest, away from the hotspot, so the volcanoes stop ocean floor creeps slowly northwest, each
erupting and gradually sink below the waves. volcano falls extinct, and a new one starts
erupting over the stationary hotspot.

Kauai is the oldest of the The deeply eroded volcanoes
This island has sunk
below sea level, forming main islands. Its volcano last on Oahu have been extinct
erupted 500,000 years ago.
for 10,000 years.
a flat-topped seamount
called a guyot.
Heat currents in the upper
mantle are dragging the
Pacific Plate very slowly
across the globe.

Earth’s mantle is made
of heavy, very hot rock.
It is solid, but flows very
slowly, like putty.

AT A GLANCE

STATS AND FACTS

• LOCATION Central Pacific Ocean The Hawaiian island MOVING PLATE ISLAND CHAINS
The Pacific Plate
Combined, the
• VOLCANO TYPE Oceanic shield volcano chain has 132 moves northwest Hawaiian island and
volcanic islands and
by about 4 in
the Emperor Seamount
• LENGTH The Hawaiian island chain atolls. The chain (10 cm) a year. chain stretches over
3,600 miles (5,800 km).
extends northwest
is 1,490 miles (2,400 km) long in the form of over
• HEIGHT The summit of the highest 80 extinct underwater HIGHEST MOUNTAIN SEAMOUNTS
volcano, Mauna Kea, is 13,802 ft (4,207 m) volcanoes—known If measured from the The youngest seamount,
as the Emperor
above sea level. base on the ocean floor Loihi, began forming about
Seamount chain. to its summit, Mauna 400,000 years ago; the oldest
Kea is the highest named seamount, Meiji,
mountain on Earth. is 85 million years old.

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