Speaker 1: Welcome to Brainstuff, a production of iHeartRadio. Hey Brainstuff, Lauren Vogelbaum. Here.
Speaker 1: When the explorer Ferdinand Magellan visited Earth's biggest ocean in
Speaker 1: fifteen twenty, he found the waters pleasantly calm, and that's
Speaker 1: why to this day we call it the Pacific Ocean,
Speaker 1: a pacific meaning peaceful, which is ironic considering that there's
Speaker 1: a vast loop of volcanoes and seismic activity running through
Speaker 1: and around the Pacific Ocean. This is the infamous Ring
Speaker 1: of Fire, a perimeter some twenty five thousand miles long.
Speaker 1: That's forty thousand kilometers where most of the world's earthquakes
Speaker 1: and volcanic vents take place. Today, let's talk about how
Speaker 1: it works. Spoiler alert, it's got nothing to do with
Speaker 1: the love song made popular by Johnny Cash. Unfortunately. The
Speaker 1: Ring of Fire hugs the western coast of South, Central and
Speaker 1: North America, spans Alaska's Aleutian Island Arc through Rushes cam
Speaker 1: Chocup Peninsula, then shoots down through Japan, the Philippines, Indonesia,
Speaker 1: pap New Guinea, and New Zealand. The ring completes itself
Speaker 1: by going through northwestern Antarctica, which has a number of volcanoes.
Speaker 1: All of these areas touch on the Pacific tectonic Plate
Speaker 1: and a few smaller plates that brush up against it. Okay,
Speaker 1: you and I live on top of the Earth's lithosphere,
Speaker 1: our home world's rocky exterior crust. But this layer isn't
Speaker 1: some rigid, single piece shell. Instead, it's made up of
Speaker 1: about fifteen to twenty tectonic plates depending on who you ask,
Speaker 1: that fit together pretty snugly and slowly drift over the
Speaker 1: molten materials that lay deeper inside our planet. A heat
Speaker 1: from the Earth's core causes them to move against one another.
Speaker 1: Boundaries between these plates come in three major categories, convergent, divergent,
Speaker 1: and transform, and the Ring of Fire includes examples of
Speaker 1: each one. Let's start with divergent boundaries. These occur when
Speaker 1: two neighboring plates move away from one another. In those areas,
Speaker 1: molten magma rises up from beneath the plates and eventually
Speaker 1: hardens to create new crust. Under the Pacific Ocean, the
Speaker 1: huge Pacific Plate is being pushed away from four of
Speaker 1: its smaller counterparts by the powerful East Pacific Rise. This
Speaker 1: is a strip of heavy activity that parallels the coast
Speaker 1: of South America a couple thousand miles out, stretching from
Speaker 1: the Gulf of California down through Easter Island, approaching Antarctica
Speaker 1: and New Zealand. Around Easter Island, which is offshore of Chile,
Speaker 1: we see the fastest expansion of the Earth's crust in
Speaker 1: the world, over six inches a year, or about one
Speaker 1: hundred and fifty millimeters. Divergent boundaries also create hydrothermal vents
Speaker 1: deep in the ocean that spew material and heat into
Speaker 1: the water, and researchers have found fascinating ecosystems there that,
Speaker 1: unlike any other ecosystem on Earth, doesn't have photosynthesis as
Speaker 1: its base. These creatures live off the vents independent of
Speaker 1: the Sun's energy. Next, let's talk about transform boundaries, areas
Speaker 1: where two plates sideswipe each other up. In California proper,
Speaker 1: we have the San Andreas Fault. That's a classic transform boundary.
Speaker 1: The state of California is straddled across the Pacific Plate
Speaker 1: and the North American Plate. The North American Plate is
Speaker 1: headed south, the Pacific is moving north. A friction between
Speaker 1: them causes the earthquakes that California is infamous for. But
Speaker 1: what happens when plates collide head on. That's a convergent
Speaker 1: boundary wherein one plate will be driven underneath the other.
Speaker 1: This point of contact is called a subduction zone. The
Speaker 1: Pacific Plate has a subduct zone at its northwestern rim,
Speaker 1: along its boundary with the Philippine Sea Plate, which is
Speaker 1: riding up over the Pacific Plate. This interaction caused part
Speaker 1: of the Philippine Plate to break off millions of years ago,
Speaker 1: forming a tiny plate in between called the Mariana which
Speaker 1: is also riding over the Pacific Plate. These interactions forged
Speaker 1: the Mariana Islands, one thousand miles east of the Philippine
Speaker 1: Archipelago and created the yawning underwater chasm called the Mariana Trench,
Speaker 1: which contains the deepest point of any ocean on Earth.
Speaker 1: Its floor, named the Challenger Deep, lies some thirty six
Speaker 1: thousand feet below sea level. That's around eleven thousand meters.
Speaker 1: For contrast, the peak of Mount Everest is only twenty
Speaker 1: nine thousand feet above sea level or nine thousand meters,
Speaker 1: which means the Mariana Trench is significantly deeper than Everest
Speaker 1: is tall. Around this and other subduction zones, researchers are
Speaker 1: investigating reservoirs of hot water moving up from the ocean
Speaker 1: floor as a potential source of geothermal energy. Solar and
Speaker 1: wind power grab more headlines, but engineers are also working
Speaker 1: on harnessing these underwater geothermal sources of cleaner energy. Meanwhile,
Speaker 1: across the ocean, between the southeast part of the Pacific
Speaker 1: Plate and the South American Continental Plate, there's a smaller
Speaker 1: oceanic plate called the Nasca. At this very moment, the
Speaker 1: Nasca Plate is being driven underneath the South American Plate.
Speaker 1: The convergence process sets off a lot of earthquakes in
Speaker 1: western South America. It's also uplifting mountains and sending up
Speaker 1: magma to feed volcanoes. There are some four hundred and
Speaker 1: fifty two volcanoes, both active and dormant, spread out across
Speaker 1: throwing a fire, including plenty of vents and fissures that
Speaker 1: arept underwater. As far as we know, these account for
Speaker 1: seventy five percent of all volcanic activity in the world.
Speaker 1: The area also accounts for around ninety percent of the
Speaker 1: planet's earthquakes. Some of the worst natural disasters in recorded history,
Speaker 1: like the eighteen eighty three Krakatoa eruption, the nineteen sixty
Speaker 1: Chile earthquake and the two thousand and four Indian Ocean
Speaker 1: tsunami had their origins along the Ring of Fires tectonic boundaries. However,
Speaker 1: there are so many small plates and different interaction zones
Speaker 1: involved in the Ring that any disasters that happen on
Speaker 1: opposite sides of it are just coincidence. A case in point,
Speaker 1: a series of earthquakes rocked Japan's Kshu Island in April
Speaker 1: of twenty sixteen. That same month, Chile suffered a quake
Speaker 1: with a Richter scale magnitude of seven point two. The
Speaker 1: epicenters were almost ten thousand miles apart for sixteen thousand kilometers.
Speaker 1: Although a strong earthquake can trigger weaker ones in nearby places,
Speaker 1: the gap between Chile and Japan is far too big
Speaker 1: for the ethquakes to be linked. After all, the Pacific
Speaker 1: is the world's largest ocean, though it may not always
Speaker 1: retain that title do in no small part to all
Speaker 1: the subduction zones on its flanks. The Pacific might close
Speaker 1: within the next two hundred and fifty million years. As Asia, Australia,
Speaker 1: and the Americas converge. Planet Earth may wind up with
Speaker 1: a new super continent not too dissimilar from the giant
Speaker 1: land mass called Pangaea that started breaking apart around two
Speaker 1: hundred million years ago. But that's just one hypothesis. Some
Speaker 1: geologists think that the Atlantic or the Arctic oceans are
Speaker 1: more likely to disappear than the Pacific. We'll all just
Speaker 1: have to wait and find out. Today's episode is based
Speaker 1: on the article seven hot facts about the Pacific Ring
Speaker 1: of Fire on HowStuffWorks dot com, written by Mark Mancini.
Speaker 1: Brain Stuff is production by Heart Radio in partnership with
Speaker 1: hostiff works dot Com and is produced by Tyler Klang
Speaker 1: and Ramsey young A. Four more podcasts from my heart Radio.
Speaker 1: Visit the iHeartRadio app, Apple Podcasts, or wherever you listen
Speaker 1: to your favorite shows. M