thanks to brilliant for supporting this
whole week of scishow go to brilliant
org slash scishow to learn more the
hottest region on earth is in Eastern
Africa but the heat might be the least
interesting thing about it it has a
volcano featuring one of the planet's
few lava lakes places where molten rock
sits exposed full-time and it has some
of the Earth's hottest saltiest and most
acidic natural water but hominids like
us humans have lived nearby for millions
of years including one whose skeleton is
so famous I bet you know her name
welcome to Ethiopia's Donna killed
depression home to all of the extreme
sand to Lucy thanks to its super arid
desert climate the Donegal depression is
so dry that major rivers just dry up
there without ever reaching the sea and
the Donegal depression gets hot Death
Valley California might have the hottest
verified days on record but on average
over the whole year Donna kill is hotter
than anywhere else on earth and it's not
even like a close contest measurements
showed that on average Donna kill is
about 34 degrees Celsius that's a couple
degrees hotter than anywhere else on
earth and at least 9 degrees hotter than
Death Valley but here he doesn't just
come from the Sun it's called the Donna
kill depression because it's a lower
than everything else around at around
125 meters below sea level it's so low
because Donna kil is the junction of
three tectonic plates the Nubian the
somalian and the Arabian and those
plates are spreading apart leaving the
region between them to sink lower and
lower and just like everything else with
this area the Donegal depression isn't
your average plate boundary underneath
eastern Africa there's what's known as a
mantle plume a huge mass of magma from
within the Earth's mantle is being
shoved up against the crust for reasons
that scientists don't fully understand
that plume is helping push those plates
apart and as a result the Somalian and
Nubian plates which
used to be a single plate will
completely split right near Donna Kel
this means that the Donna keel
depression is one of the few places on
earth where scientists can watch the
kinds of processes that might have
formed Earth's first plates billions of
years ago the region experiences lots of
earthquakes and hosts its own share of
volcanoes all evidence of the chaos
brewing under the crust and the Donna
Kiel depressions volcanoes work together
with its rocks to make the region look
pretty different from your classic
monochrome sandy deserts a hard cracked
ground is sometimes surprisingly
colorful where the little water that's
available mixes with iron and copper and
sulfur from volcanoes and salt from the
rocks to produce a rainbow that you
would not want to swim in that water is
about as acidic as battery acid 10 times
as bad as the acid your stomach uses to
kill bacteria and it's heated to around
boiling by all that magma beneath the
surface
and by the way the airs not much better
in some spots it has so much chlorine in
it that it will burn your throat if you
don't wear a gas mask but remarkably
even here scientists have found a kind
of life called extremophiles microbes
adapted to thrive and what we would
usually think of as inhospitable
environments and they haven't has found
one type of extremophiles
there are at least a couple Hardy little
organisms there and they're tolerant to
so many different extreme conditions
that they're not just extremophiles they
are poly extremophiles now what you
won't find in the Donna keel depression
today is many larger organisms because
it's honestly a pretty unpleasant place
what would the ultra-hot days and the
throat corroding air and the pools of
boiling acid although humans do visit
sometimes in 1974 a team of scientists
in the area stumbled upon the partial
skeleton of a kind of hominid who used
to live there called Australopithecus
afarensis
at night they were listening to the
Beatles and thought of the perfect name
for their discovery Lucy hominids
include every species related to humans
since we split from the African Apes
several million years ago Lucy lived a
little more than 3 million years ago and
when they
found her she was the oldest most
complete early hominid ever discovered
Lucy helped us write the story of
hominid evolution helping to answer tons
of questions while also inspiring lots
of new ones
despite her fame we still don't know
exactly where she and her closest
relatives sit on our family tree that's
okay
scientists can handle uncertainty it
comes with the job but we do know is
that when Lucy was around the Donna
killed depression did not look like it
does today it's special combination of
heat plate tectonics elevation acid and
volcanism probably only kicked into high
gear about a century ago and it won't
last forever either millions of years
from now the African and Arabian plates
will have spread far enough apart that
the nearby Red Sea will be able to flow
right into the depression that they're
currently creating and a brand new ocean
will sit where Lucy once climbed trees
we're just lucky to live right now we
get to be on earth when this incredibly
weird unique place exists for us to see
and talk about or if not lucky like or
something humans really love knowing
about stuff and that's what drives us to
study even remote unforgiving places
like this one to learn more about the
world and if you like learning more
every day you might be interested in the
daily challenges on brilliant org every
day they post new challenge questions
covering topics like statistics
electricity and computer science each
one ties into a related course on
brilliant so you can also learn about
the topic in depth if it piques your
interest these daily challenges are a
fun bite-sized way to learn something
new every day whether you're passing
time on the train or just want to make
some time for curiosity the daily
challenges are free for everyone but
premium members get access to the whole
archive of challenges and it just so
happens that the first 200 people to
sign up at brilliant org slash scishow
look at 20% off the annual premium
subscription so thanks for checking it
out
[Music]