What Is the Pacific Ring of Fire?

The Ring of Fire is a loop around the Pacific Ocean that's a literal hotbed of volcanoes, earthquakes, hydrothermal vents, and other geologic activity. Learn how the interactions among tectonic plates cause all this mayhem in today's episode of BrainStuff, based on this article: https://science.howstuffworks.com/environmental/earth/geology/ring-of-fire.htm

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Episode Transcript

Speaker 1 (00:01):
Welcome to Brainstuff, a production of iHeartRadio. Hey Brainstuff, Lauren Vogelbaum. Here.
When the explorer Ferdinand Magellan visited Earth's biggest ocean in
fifteen twenty, he found the waters pleasantly calm, and that's
why to this day we call it the Pacific Ocean,

(00:22):
a pacific meaning peaceful, which is ironic considering that there's
a vast loop of volcanoes and seismic activity running through
and around the Pacific Ocean. This is the infamous Ring
of Fire, a perimeter some twenty five thousand miles long.
That's forty thousand kilometers where most of the world's earthquakes

(00:44):
and volcanic vents take place. Today, let's talk about how
it works. Spoiler alert, it's got nothing to do with
the love song made popular by Johnny Cash. Unfortunately. The
Ring of Fire hugs the western coast of South, Central and
North America, spans Alaska's Aleutian Island Arc through Rushes cam

(01:05):
Chocup Peninsula, then shoots down through Japan, the Philippines, Indonesia,
pap New Guinea, and New Zealand. The ring completes itself
by going through northwestern Antarctica, which has a number of volcanoes.
All of these areas touch on the Pacific tectonic Plate
and a few smaller plates that brush up against it. Okay,

(01:27):
you and I live on top of the Earth's lithosphere,
our home world's rocky exterior crust. But this layer isn't
some rigid, single piece shell. Instead, it's made up of
about fifteen to twenty tectonic plates depending on who you ask,
that fit together pretty snugly and slowly drift over the
molten materials that lay deeper inside our planet. A heat

(01:51):
from the Earth's core causes them to move against one another.
Boundaries between these plates come in three major categories, convergent, divergent,
and transform, and the Ring of Fire includes examples of
each one. Let's start with divergent boundaries. These occur when
two neighboring plates move away from one another. In those areas,

(02:15):
molten magma rises up from beneath the plates and eventually
hardens to create new crust. Under the Pacific Ocean, the
huge Pacific Plate is being pushed away from four of
its smaller counterparts by the powerful East Pacific Rise. This
is a strip of heavy activity that parallels the coast
of South America a couple thousand miles out, stretching from

(02:38):
the Gulf of California down through Easter Island, approaching Antarctica
and New Zealand. Around Easter Island, which is offshore of Chile,
we see the fastest expansion of the Earth's crust in
the world, over six inches a year, or about one
hundred and fifty millimeters. Divergent boundaries also create hydrothermal vents
deep in the ocean that spew material and heat into

(03:00):
the water, and researchers have found fascinating ecosystems there that,
unlike any other ecosystem on Earth, doesn't have photosynthesis as
its base. These creatures live off the vents independent of
the Sun's energy. Next, let's talk about transform boundaries, areas

(03:21):
where two plates sideswipe each other up. In California proper,
we have the San Andreas Fault. That's a classic transform boundary.
The state of California is straddled across the Pacific Plate
and the North American Plate. The North American Plate is
headed south, the Pacific is moving north. A friction between
them causes the earthquakes that California is infamous for. But

(03:46):
what happens when plates collide head on. That's a convergent
boundary wherein one plate will be driven underneath the other.
This point of contact is called a subduction zone. The
Pacific Plate has a subduct zone at its northwestern rim,
along its boundary with the Philippine Sea Plate, which is
riding up over the Pacific Plate. This interaction caused part

(04:09):
of the Philippine Plate to break off millions of years ago,
forming a tiny plate in between called the Mariana which
is also riding over the Pacific Plate. These interactions forged
the Mariana Islands, one thousand miles east of the Philippine
Archipelago and created the yawning underwater chasm called the Mariana Trench,
which contains the deepest point of any ocean on Earth.

(04:33):
Its floor, named the Challenger Deep, lies some thirty six
thousand feet below sea level. That's around eleven thousand meters.
For contrast, the peak of Mount Everest is only twenty
nine thousand feet above sea level or nine thousand meters,
which means the Mariana Trench is significantly deeper than Everest
is tall. Around this and other subduction zones, researchers are

(04:57):
investigating reservoirs of hot water moving up from the ocean
floor as a potential source of geothermal energy. Solar and
wind power grab more headlines, but engineers are also working
on harnessing these underwater geothermal sources of cleaner energy. Meanwhile,
across the ocean, between the southeast part of the Pacific

(05:20):
Plate and the South American Continental Plate, there's a smaller
oceanic plate called the Nasca. At this very moment, the
Nasca Plate is being driven underneath the South American Plate.
The convergence process sets off a lot of earthquakes in
western South America. It's also uplifting mountains and sending up
magma to feed volcanoes. There are some four hundred and

(05:44):
fifty two volcanoes, both active and dormant, spread out across
throwing a fire, including plenty of vents and fissures that
arept underwater. As far as we know, these account for
seventy five percent of all volcanic activity in the world.
The area also accounts for around ninety percent of the
planet's earthquakes. Some of the worst natural disasters in recorded history,

(06:08):
like the eighteen eighty three Krakatoa eruption, the nineteen sixty
Chile earthquake and the two thousand and four Indian Ocean
tsunami had their origins along the Ring of Fires tectonic boundaries. However,
there are so many small plates and different interaction zones
involved in the Ring that any disasters that happen on

(06:29):
opposite sides of it are just coincidence. A case in point,
a series of earthquakes rocked Japan's Kshu Island in April
of twenty sixteen. That same month, Chile suffered a quake
with a Richter scale magnitude of seven point two. The
epicenters were almost ten thousand miles apart for sixteen thousand kilometers.

(06:50):
Although a strong earthquake can trigger weaker ones in nearby places,
the gap between Chile and Japan is far too big
for the ethquakes to be linked. After all, the Pacific
is the world's largest ocean, though it may not always
retain that title do in no small part to all
the subduction zones on its flanks. The Pacific might close

(07:11):
within the next two hundred and fifty million years. As Asia, Australia,
and the Americas converge. Planet Earth may wind up with
a new super continent not too dissimilar from the giant
land mass called Pangaea that started breaking apart around two
hundred million years ago. But that's just one hypothesis. Some
geologists think that the Atlantic or the Arctic oceans are

(07:33):
more likely to disappear than the Pacific. We'll all just
have to wait and find out. Today's episode is based
on the article seven hot facts about the Pacific Ring
of Fire on HowStuffWorks dot com, written by Mark Mancini.
Brain Stuff is production by Heart Radio in partnership with
hostiff works dot Com and is produced by Tyler Klang

(07:55):
and Ramsey young A. Four more podcasts from my heart Radio.
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