Antarctic Ice Fields

The Antarctic ice ranges from an average depth of 2,160mtrs to a maximum depth of 4,770 mtr. and it is largely resting on rock....That would make a very serious icy pole aye! That is a lot of ice folks, we would not want it all to melt into the ocean aye.
You have to wonder what dinosaurs are lying on the rocks at the bottom of that ice. When did that ice start to form? (maybe 65 million years ago at the end of the last extinction period ?) How did it get to 4 k deep/ Must have been some serious climate changes taking place that puts our current little bit of global warming to shame.
There are active volcano's beneath that ice and there could be rivers and lakes and stuff as well, depending possibly on how close the magma is to the over lying rock and ice.

Are you sure that's not Greenland Adrian? I'll check it out anyway.
If the ice is 4.77ks deep it's all below sea level anyway so it won't make any difference to sea level.

Great topic.

No not Greenland.
Little bit of info here:
https://en.wikipedia.org/wiki/Antarctic_ice_sheet

These pics show the ice cover and the underlying land mass.




The ice overlaying  the land mass has not displaced any ocean water therefore if it all melted it would flow into the ocean and raise sea levels significantly.

adrian ss wrote:No not Greenland.
Little bit of info here:
https://en.wikipedia.org/wiki/Antarctic_ice_sheet

These pics show the ice cover and the underlying land mass.




The ice overlaying  the land mass has not displaced any ocean water therefore if it all melted it would flow into the ocean and raise sea levels significantly.

Its estimated that if all the Antarctic ice sheet melted sea level would be raised by 65 meters!

I like the picks and not wanting to kill off the topic too early but we both know it can't happen right?
Ice don't melt below 0 degrees C.

Maybe someone will disagree....wait for it... He beat me to it. ha ha.

butch wrote:I like the picks and not wanting to kill off the topic too early but we both know it can't happen right?
Ice don't melt below 0 degrees C.

 ha ha.

Why then is Greenland land ice melting?
Why then is almost every glacier in the world rapidly retreating?

You just misquoted me. Grabbing at straws again.

Greenland isn't melting.
The Arctic winter ice extent has been larger year after year for the past several years.
The Antarctic winter ice extent measured the largest extent in 2014...the largest ever recorded.

Thought this was about Antarctica?

65mtr is about right. There is a lot of ice above sea level over Antarctica. Also down deep near bedrock (Grounding Line) the land mass can be quite warm due to volcanic activity and closeness of magma. There are lakes and rivers beneath this ice that has scientists a bit baffled as to their ebbing and flowing.

    Very true ice does not melt below zero deg C.
My understanding is that ice will melt when under pressure, so maybe the ice at the Grounding Line is melting due to the high pressure from the overlying ice which may explain how a deep below sea level glacier with a couple of km of ice above it,can flow over the the grounding line rock surface. Definitely some strange things going on beneath Antarctic ice fields.

butch wrote:Greenland isn't melting.

wrong! Greenland is loosing ice mass .
The Greenland Ice Sheet Has Lost 3.8 Trillion Tons of Ice  since 1992!
"The results of IMBIE 2016 were published in 2018 for Antarctica and in 2019 for Greenland. By combining the results of 50 different surveys produced by 89 participants from 50 international organisations, we produced reconciled time-series of ice sheet mass balance, showing that the Antarctic and Greenland Ice Sheets contributed 17.8 ± 1.8 mm to global sea level rise between 1992 and 2017.
The Antarctic Ice Sheet lost 2720 ± 1390 billion tonnes of ice between 1992 and 2017, with a 4-fold increase in the rate of mass loss between the first five years of our survey (1992-1997) and the last five years of our survey (2012-2017). West Antarctica experienced the largest change with the rate of mass loss rising from 53 ± 29 billion tonnes per year at the start of our survey to 159 ± 26 billion tonnes per year at the end of our survey due to increased ocean melting at Pine Island and Thwaites Glaciers causing glacier speedup. The Antarctic Peninsula also experienced increased ice losses following the collapse of Larsen B and Wilkins ice shelves with the rate of ice loss increasing from 7 ± 13 billion tonnes to 33 ± 16 billion tonnes per year. Finally, East Antarctica, where mass balance fluctuations are primarily driven by snowfall accumulation, has remained close to a state of balance with a small gain of 5 ± 46 billion tonnes of ice per year between 1992 and 2017.

The Greenland Ice Sheet lost 3902 ± 342 billion tonnes of ice between 1992 and 2018. Over half of Greenland’s ice losses comes from increased meltwater runoff driven by warmer atmospheric  conditions, with the remainder originating from dynamical imbalance. The rate of ice loss has dramatically increased over the course of our survey, rising from 26 ± 27 billion tonnes per year in the early 1990s to 244 ± 28 billion tonnes per year between 2012 and 2017."
http://imbie.org/imbie-2016/results/
Mass balance of the Greenland Ice Sheet from 1992 to 2018
Abstract
The Greenland Ice Sheet has been a major contributor to global sea-level rise in recent decades1,2, and it is expected to continue to be so3. Although increases in glacier flow4,5,6 and surface melting7,8,9 have been driven by oceanic10,11,12 and atmospheric13,14 warming, the magnitude and trajectory of the ice sheet’s mass imbalance remain uncertain. Here we compare and combine 26 individual satellite measurements of changes in the ice sheet’s volume, flow and gravitational potential to produce a reconciled estimate of its mass balance. The ice sheet was close to a state of balance in the 1990s, but annual losses have risen since then, peaking at 345 ± 66 billion tonnes per year in 2011. In all, Greenland lost 3,902 ± 342 billion tonnes of ice between 1992 and 2018, causing the mean sea level to rise by 10.8 ± 0.9 millimetres. Using three regional climate models, we show that the reduced surface mass balance has driven 1,964 ± 565 billion tonnes (50.3 per cent) of the ice loss owing to increased meltwater runoff. The remaining 1,938 ± 541 billion tonnes (49.7 per cent) of ice loss was due to increased glacier dynamical imbalance, which rose from 46 ± 37 billion tonnes per year in the 1990s to 87 ± 25 billion tonnes per year since then. The total rate of ice loss slowed to 222 ± 30 billion tonnes per year between 2013 and 2017, on average, as atmospheric circulation favoured cooler conditions15 and ocean temperatures fell at the terminus of Jakobshavn Isbræ16. Cumulative ice losses from Greenland as a whole have been close to the rates predicted by the Intergovernmental Panel on Climate Change for their high-end climate warming scenario17, which forecast an additional 70 to 130 millimetres of global sea-level rise by 2100 compared with their central estimate.
https://www.nature.com/articles/s41586-019-1855-2

butch wrote:
The Arctic winter ice extent has been larger year after year for the past several years.

Again this is simply wrong!
Introduction
Over the period of modern satellite observations (1979- present), Arctic sea-ice extent at the end of the melt season (September) has declined at a rate of >11% per decade, and there is evidence that the rate of decline has accelerated during the last decade. Every September since 1996 the sea- ice extent has been below the 1979-99 mean. Ice extent for September 2010 was the third lowest in the satellite record for the month, behind 2007 (lowest) and 2008 (second lowest) (US National Snow and Ice Data Center (NSIDC), http://nsidc.org/arcticseaicenews/2010/100410.htm, 2010). For the last 4 years, September ice extent has been below two standard deviations below the long-term climatic mean. The winter ice extent has also been declining, but at a slower rate, although 2011’s winter maximum ice extent was close to the lowest in the satellite record. The sea-ice cover is also thinning (e.g. Reference Rothrock, Yu and MaykutRothrock and others, 1999). According to Reference Kwok and D.A.Kwok and others (2009), the Arctic Ocean has lost 40% of its multiyear ice in the last 5 years. At the end of summer 2010, <15% of the ice remaining in the Arctic was >2 years old, compared to 50-60% during the 1980s (NSIDC, http://nsidc.org/arcticseaicenews/2010/100410.htm). There is virtually none of the oldest (at least 5 years old) ice remaining in the Arctic (<60000 km2, compared to 2 × 106km2 during the 1980s).
https://www.cambridge.org/core/journals/journal-of-glaciology/article/arctic-seaice-change-a-grand-challenge-of-climate-science/845FA37029045EFA928FE0301C46ADC5
Arctic sea ice decline stalls out at second lowest minimum
September 21, 2020
On September 15, Arctic sea ice likely reached its annual minimum extent of 3.74 million square kilometers (1.44 million square miles). The minimum ice extent is the second lowest in the 42-year-old satellite record, reinforcing the long-term downward trend in Arctic ice extent. Sea ice extent will now begin its seasonal increase through autumn and winter. In the Antarctic, sea ice extent is now well above average and within the range of the ten largest ice extents on record, underscoring its high year-to-year variability. The annual maximum for Antarctic sea ice typically occurs in late September or early October.
http://nsidc.org/arcticseaicenews/2020/09/

Look yez blokes I am talking about the Antarctic ice fields not the Arctic.....
Yes the Arctic ice is reducing at a rapid rate coz the ocean around it is warming......The same reason that the Antarctic SEA ICE and the ICE SHELF is melting.
So ya gotta ask; Why is the ocean temps near the Ice shelf and surrounding the sea ice getting warmer....although to me it does not seem to have altered much at all over the past twenty years or so.....(Antarctica only)

This about the Antarctic:
https://www.pnas.org/doi/10.1073/pnas.1906556116

You already have my view Adrian.

butch wrote:Greenland isn't melting.
The Arctic winter ice extent has been larger year after year for the past several years.
The Antarctic winter ice extent measured the largest extent in 2014...the largest ever recorded.

Thought this was about Antarctica?

adrian ss wrote:Look yez blokes I am talking about the Antarctic ice fields not the Arctic.....
Yes the Arctic ice is reducing at a rapid rate coz the ocean around it is warming......The same reason that the Antarctic SEA ICE  and the ICE SHELF is melting.
So ya gotta ask; Why is the ocean temps near the Ice shelf and surrounding the sea ice getting warmer....although to me it does not seem to have altered much at all over the past twenty years or so.....(Antarctica only)

This about the Antarctic:
https://www.pnas.org/doi/10.1073/pnas.1906556116

Antarctica lost 2,720 ± 1,390 billion tonnes of ice between 1992 and 2017 based on satellite and other data.
5 Visible Signs of Climate Change in Antarctica
https://impakter.com/5-visible-signs-of-climate-change-in-antarctica/
Antarctic sea ice extent this year is the lowest ever recorded since 1979 when satellite monitoring commenced.

Nothing to do with the Antarctic ice but the frozen pole caps of Mars is also reducing at a rapid rate. Looks like climate change is far reaching Aye!!

adrian ss wrote:Nothing to do with the Antarctic ice but the frozen pole caps of Mars is also reducing at a rapid rate. Looks like climate change is far reaching Aye!!

That's a topic killer.

Not before time.

butch wrote:

adrian ss wrote:Nothing to do with the Antarctic ice but the frozen pole caps of Mars is also reducing at a rapid rate. Looks like climate change is far reaching Aye!!

That's a topic killer.

Not before time.

You might be wrong there Butch I think it will go on another path with someone telling us why Mar's poles are melting. Is our CO2 getting shipped to Mars?

I'll be happy with that Geof so long as 'someone' is not a politically motivated activist, scientifically illiterate or a climate change lemming.

adrian ss wrote:Nothing to do with the Antarctic ice but the frozen pole caps of Mars is also reducing at a rapid rate. Looks like climate change is far reaching Aye!!

The mars ice caps are mostly frozen CO2 and wax and wane due the seasonal variations.The seasonal polar caps are made of martian air that freezes during winter. Depending on the time of year, more than a quarter of the martian atmosphere can be found lying on the ground around the poles. (The atmosphere is 95% CO2; that's why the seasonal polar caps are made of dry ice.)
As seasons come and go, carbon dioxide shifts back and forth--lying on the ground during cold months, floating through the air during warmer months.

butch wrote:I'll be happy with that Geof so long as 'someone' is not a politically motivated activist, scientifically illiterate or a climate change lemming.

Describes you butch to a tee and in addition we can add conspiracy theorist! So far everything you have posted on climate change has either been utter scientific nonsense not supported by any credible evidence or just plain conspiracy rubbish!

planetcare wrote:

butch wrote:I'll be happy with that Geof so long as 'someone' is not a politically motivated activist, scientifically illiterate or a climate change lemming.

Describes you butch to  a tee and in addition we can add conspiracy theorist! So far everything you have posted on climate change has either been utter scientific nonsense not supported by any credible evidence or just plain  conspiracy rubbish!

right on queue planetcare, or Doug or Ironstone, or Marshall, oh that's right both Doug and Marshall were banned from here so now you disguise yourself as planetcare, WTF you are really on another planet you don't fit in here.

davsgold wrote:

planetcare wrote:

butch wrote:I'll be happy with that Geof so long as 'someone' is not a politically motivated activist, scientifically illiterate or a climate change lemming.

Describes you butch to  a tee and in addition we can add conspiracy theorist! So far everything you have posted on climate change has either been utter scientific nonsense not supported by any credible evidence or just plain  conspiracy rubbish!

right on queue planetcare, or Doug or Ironstone, or Marshall, oh that's right both Doug and Marshall were banned from here so now you disguise yourself as planetcare, WTF you are really on another planet you don't fit in here.    

Thank you for your opinion! Opinions are like back sides everyone has one!
Have a nice day!

The martian ice caps are shrinking. As they are made mostly of frozen carbon dioxide, this evaporation could trigger an increase in Mars' own greenhouse effect.

Images from the Mars Global Surveyor spacecraft show that ice ridges and escarpments have retreated over the past two years or so. The orbiting probe has also captured the ice thickening and thinning with the passing seasons.

The reason for the change is not yet clear. But it means that Mars' climate may be changing. "These observations," say Michael Malin and co-workers at Malin Space Science Systems in San Diego, California, "suggest that the present martian environment is neither stable nor typical of the past."

Malin and his colleagues studied photos of the two ice caps taken between October 1999 and August 20011. The pictures show ridges and pits of ice, some just a few metres wide. In some places, the edges of these features seem to have retreated by up to three metres over the observation period.

In other words, the ice caps have shrunk, irrespective of seasonal changes. The researchers estimate that if all the losses are due to evaporation of carbon dioxide, the amount of this gas in the atmosphere must be increasing by about 1% every martian decade.

Mars' atmosphere is very thin - its pressure is less than 1% of that on Earth - and consists mostly of carbon dioxide. But enough carbon dioxide evaporating from the poles would make a big difference. Because atmospheric carbon dioxide prevents solar heat radiating back into space, it warms the planet.

TheMars Global Surveyor also carries a laser altimeter, an instrument that can track changes of as little as a few centimetres in the height of the ice2.

Using this device, David Smith of NASA's Goddard Space Flight Center in Maryland and co-workers have found that ice height at both poles changes by about a metre between summer and winter. This shows that there is a considerable reservoir of carbon dioxide in the ice caps that can be pumped to and from the atmosphere.

The researchers find that the size of the north and south polar caps seem to change by about the same amount, despite the fact that, because of the shape of Mars' orbit, the planet's north pole is thought to get hotter than its south..

planetcare wrote:

butch wrote:I'll be happy with that Geof so long as 'someone' is not a politically motivated activist, scientifically illiterate or a climate change lemming.

Describes you butch to  a tee and in addition we can add conspiracy theorist! So far everything you have posted on climate change has either been utter scientific nonsense not supported by any credible evidence or just plain  conspiracy rubbish!

I hit a raw nerve there. Did i mention any names? Nasty.

Don't know about Mars, haven't been there.

Adrian, your posts, have a knack of baiting up people just for the sake of arguments sake, of which 2 members on here have now been sent on a short holiday for week. Any more enticing argumentative rhetoric out of you & you'll find yourself joining them.
I wont be repeating this again, anyone who comes on here for the purpose of deliberately stirring up trouble, in order to incite argument after argument just for the purpose of arguments sake, will be short lived. No more Mr nice guy, best of luck to you fellas.

Management

From Feb 21 until today there has been 111 Off Topic Topics and 3145 replies.= 85% 0f total combined topics
From Feb 21 until today there has been 50 Topics and 536 replies.= 14.5% of total combined topics
  Seems to me that people like the Off Topic discussions and mental jousting.

Any hoo I have a migraine this morn so I will be off the air today....to the pleasure of the 14.5 percenter's.

The mental jousting you talk of as being liked Adrian, leads more to argumentative, inflammatory debate between members than humour. Something of which I find myself constantly stepping in, in order to have things calm down or sorted out.
Good sensible write ups with humour we could all use, but inflammatory/controversial write ups/post, leading to argument over argument (over crap) management & I seriously don't need.
Funny you should come down with a migraine Adrian, for that's what us management experience almost on a daily basis, with just about every write up you put down.
Stick to making sense will ya?

Kon

Fine.
I have nothing left to say about gold detecting on the forum that has not already been said a bazillion times and nobody on the forum is interested in beach and relic detecting, so I will just just talk to myself even more than I already do.

Here's a recent video clip, explaining on what the current climate of Antarctica has been going through or currently experiencing & what possible role or effects it has had on the surrounding environment.
Think of it what you wish, but don't shoot the messenger, for I ain't no climate scientist, just something that may be of interest to some  

https://www.youtube.com/watch?v=E-60bI4ZY64

Kon

adrian ss wrote:Fine.
I have nothing left to say about gold detecting on the forum that has not already been said a bazillion times and nobody on the forum is interested in beach and relic detecting, so I will just just talk to myself even more than I already do.  
   

Adrian, I'm always interested in beach /relic detecting.
I'm heading to GC beaches on Monday, not holding my breath as to finding mush as tourism has copped a real hammering. It's still like a breath of fresh air to wander along the low tide mark with the headset on.
I'll post up "all" my finds when I get back but I'm fairly sure you know what a rusty bottle cap looks like
I went down the GC a week ago and tried running in Park 1 but far too noisy (Black sands? and possibly wifi). I did try running the GB at 1 rather than 0 and it may be coincidence but a lot more of the rusty half bottle caps begun to be detected. I'd left my test pieces at home so had nothing to definitively compare with, I'll bury a goldy in the wet and do some further testing on the GB

Kon61gold wrote:Here's a recent video clip, explaining on what the current climate of Antarctica has been going through or currently experiencing & what possible role or effects it has had on the surrounding environment.
Think of it what you wish, but don't shoot the messenger, for I ain't no climate scientist, just something that may be of interest to some  

https://www.youtube.com/watch?v=E-60bI4ZY64

Kon

Antarctica is losing ice at an accelerating rate. How much will sea levels rise?