Today we're on a walk out of Scott Base along the McMurdo road to have a look at Observation Hill
So we're in a place where the views are spectacular and Observation Hill
is the place to go to get a 360 perspective.
So we have walked toward McMurdo Station and around the back of Observation Hill and this
is our pathway to the top! So there is a track. I will first of all point out though that if we come
this way...welcome to McMurdo Station. This is the largest settlement in Antarctica. Something like
a thousand people can reside at McMurdo Station at any one time. It's the American base it's
got an incredible amount of facilities for Science and science support. So let's go up Obs Hill!
We're at the top of Observation Hill! What an amazing viewpoint So what I'd like to do now is
I'm going to show you the landscape with a 360 view. So first of all let's look over this way:
And the green buildings down there that's Scott Base.
And behind them to the left you may be able to see the ripples on the ice shelf. Those are the
pressure ridges where the ice shelf is pushing up against the land in the area around Scott
Base. And what we'll do is we'll turn to the right and now we are looking across the Ross Ice Shelf.
And the first Landmark that we see is White Island and beyond White Island far away in the
gap between White Island and what's called Black Island, there's a little distant pimple and that is
more or less due south. And so then we go past the cross and Black Island in the background and you
may just be able to make out Mount Discovery which is a sort of rounded shield volcano.
and we'll come to the right of that which is Brown's Peninsula that dark
bit of Rocky Hill / Mountain to the right of Mount Discovery. And then as we continue
you can see some clouds but beyond the clouds there is a range of white mountains and that is
the Royal Society Range in the part of the Transantarctic Mountain Range. And the Royal Society
mountains reach up to a height of just over 4 000 metres. And as you keep going to the right you can
see some big glaciers, one of which is the Ferrar Glacier - an enormous river of ice slowly making its
way off the mountains into McMurdo Sound which is a whole flat area of sea ice in front of us.
And we can see McMurdo Station which we saw before. And then we're going to carry on round to see
the beautiful and spectacular Mount Erebus, the most southerly active volcano on Earth.
And this big shield volcano is 3794 metres above sea level. It's almost continually smoking a little
bit - a little puff of smoke or steam coming out of the crater which is actually a lava lake
down in the crater at the top. And so then if we carry on around we can see below - actually
straight below Mount Erebus is the black square rocky shape that is Castle Rock.
And then to the right of Castle Rock we have a sort of flat topped crater that's Crater Hill.
Just to the right of it is the wind farm for Scott Base and if we continue in the background
there beyond the pressure ridges is Mount Terror. Now what I'm going to do is I'm going to show you
a cool little feature just along here and that says something about the history of the landscape
around here. This is literally a couple of meters off the high point of Observation Hill there is
a very smooth rock here. And the rock itself is called trachyte which is a type of volcanic
rock and it's got lines going through it because that's part of the fabric as it was moving and
congealing on its way up from deep below towards the surface. So the trachyte is this light brown color
and it's got lines going this way but if we look carefully at this particular rock slab
there are scratch marks going across the - if you like - fabric of this trachyte and those are
superficial, they're not part of the rock itself, they are just scratch marks on the surface. So
they are telling us that sometime in the past there was a glacier grinding across the top of
Observation Hill. So there was once upon a time ice here and in fact it was probably several hundred
meters above our heads. So it was moving roughly east to west across the direction of the peninsula
and so that's really cool! It's telling us that over time there were glaciers right
above us moving across and scraping the bedrock perhaps with little pebbles at the bottom of the
ice and leaving their clue about past cold climate sort of extent in the area of
Scott Base and Observation Hill. So we're just a few meters along from the cross the top of Observation
Hill and here we have found some absolutely beautiful east to west traveling glacial
striations. What we're going to do now is we're going to drop off the end of Observation Hill
and just do a little circuit around the slopes to get back to the McMurdo Road towards Scott Base.
We have to come down from the top of Observation Hill
to the loop track which runs around at half height
So we're just passing a group of seals on the sea ice there.
So we have areas on the slopes of Observation Hill that have a lot of
spatter and lava bombs from the time when this was an active volcanic area.
So one thing to say is that although Observation Hill looks like a cone, that is not its original
shape as a volcano. It has been modified by glacial action scooping out parts of the slopes. So what
you see now is the result of highly modified volcano. But what's really great in the area of rocks and spatter and
material that was thrown out of the volcano over one million years ago, is you can sometimes find
these beautiful spindle bombs. So this is some lava that was thrown out of the crater wherever that
was - we don't see it very clearly anymore - but you can see that this was liquid at the time it was
thrown out into the air and as it twisted through the air the sides of it kind of folded over onto
itself to create this spindle bomb, which is then sort of as it congealed it landed on the
slopes almost completely solid. The tail here has broken off and sometimes the ends they're
not - you know that would have been a beautiful little pointy end at both ends - but anyway there
you go - a lava bomb from Observation Hill near Scott Base. But we are going to leave this where
we found it just on the slopes so that we don't take anything away.
Homeward! A cup of tea!