David Attenborough said this is one of the most
unusual natural wonders of the world.
That's big cause he's seen a lot.
Gravity usually pulls things towards the Earth,
but not at this waterfall in West Australia.
It's called Horizontal Falls and the water pours
sideways.
What's going on there?
Hi, Renee.
So I can't quite wrap my head around this,
a horizontal waterfall?
Yeah, I have to say
when I first heard about it, I didn't
really understand it.
I think I had to look at a picture of it and I was like,
oh okay, I get it.
Extreme tides and two narrow gorges
create this natural wonder.
I guess people think that the ocean is flat
and so it couldn't have a waterfall.
But in this case, the ocean isn't flat
because we have a tide
that's moving down so quickly and water's
escaping a channel.
At it's peak, a million
litres of water gush through every second,
creating the waterfall effect.
The water cannot exit the channel fast enough,
so you end up with a very, very turbulent, fast flow.
Kimberly tides are
the largest in the southern hemisphere.
They fluctuate by a depth of 12 metres.
As the tide begins falling,
water is trying to rush out through
this very narrow channel,
but it's not able to rush out as fast
as the tide is falling outside of the bay.
Basically, this is the story
of the Kimberley in general,
is that water can't get out as fast as it's trying to
and so you have waterfalls and whirlpools and
all kinds of features.
So I have to admit, when I first heard
about the horizontal falls,
I wondered if maybe they defied gravity or
something?
Oh, it definitely obeys
the laws of gravity like everything on the Earth.
It definitely is obeying the laws of gravity.
In fact, it's gravity
that makes the tides do what they do.
And for that, we rely on outer space.
So the gravity of the Sun and the Moon is causing
the water in the oceans to basically bulge out
towards the Sun and the Moon because they
have small gravitational pull and it's enough to
just pull the ocean out towards those celestial
bodies.
Unlike your normal waterfall
that swells after heavy
rain, these falls
are strongest when solar and lunar calendars align.
So spring tides happen twice every month.
So when the Sun, the Moon
and the Earth are all in one line.
This happens at the full Moon and the new
Moon.
Those gravitational bulges are all aligned.
And so the tide is very big.
It's like adding the Sun and the Moon
bulges together, so we get a spring tide.
When the tides are right,
tourists come to
experience the incredible force.
Hi, Gabby.
So what does it feel like to cross them?
It's like a rollercoaster.
It really is.
It's
like going through a washing machine.
At peak tides, the torrent
generates whirlpools deep enough to swallow a
dinghy.
So the speed and the power of the water does make it
a little bit dangerous and why we do have to time
it with the tides
so that it is still going to be safe
for us to go through.
Say someone went overboard
that would get sucked down and spat out.
I've heard of at least one fatality.
A little recreational boat with people that just
didn't understand
how dangerous it can can be to go through
if you don't know what you're doing.
I think everyone is a bit more aware now of how
crazy driving through the falls really is.