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Ngozumpa Glacier meltwater lake hazard (Nepal)

PostPosted: Tue Dec 27, 2011 6:11 am
by Baarb
Maybe this is well known already but if not:
http://www.bbc.co.uk/news/science-environment-16317090

Re: Ngozumpa Glacier meltwater lake hazard (Nepal)

PostPosted: Tue Dec 27, 2011 6:12 pm
by Marmaduke
I have not read about this glacier but The Global Warming debate has been ongoing. I don't question that it is or is not happening, it obviously is. My question is it really possible to attribute "man" to the root cause and how much are "we" directly affecting global warming? I was in Banff/Jasper this past Sept/Oct and went to the Athabasca Glacier. From photos they know where the glacier was as of about 1860. It has receded ever since, so how much is just natural global warming?

edit- Also a side note, they had glacier tours that brought you out on the glacier in a huge "jeep" (seated like 75 people). Kinda strange that at this park they were saying man-made global warming was the cause of the receding glacier but they were driving this huge diesel burning jeep on the glacier.

Re: Ngozumpa Glacier meltwater lake hazard (Nepal)

PostPosted: Tue Dec 27, 2011 8:57 pm
by Baarb
Well without seeking any arguments (as I don't use SP to swap opinions on this kind of thing) the general consensus (regardless of whether it's a valid one) is that if you account (read: modelled using physics, chemistry and super-computers) for all the known natural contributions (solar variation, El Nino, volcanoes, orbital variations, albedo, feedback effects etc.) that there's still some long term warming going on. This warming can be largely accounted for (by most) by modelling anthropogenic contributions such as carbon dioxide, methane etc. Obviously there are lots of error bars, misunderstandings, counter-evidence and things we don't know about (just yesterday I read about a PhD proposal on the contribution of meteorites burning up in the atmosphere). The more people look at it the better handle they'll have on it, whatever's happening, or not happening. If you can make a giant hole in the ozone layer you can do other things too.

Re: Ngozumpa Glacier meltwater lake hazard (Nepal)

PostPosted: Tue Dec 27, 2011 9:12 pm
by Marmaduke
Thanks Baarb and I wasn't seeking an arguement either. As it happens in "off-route" consistantly, I'm finished with that for various reasons. But I do like reading various opinions on different subject matters and this topic has many opnions. I am not well read on the global warming topic, so I was looking for different thoughts on it.

Re: Ngozumpa Glacier meltwater lake hazard (Nepal)

PostPosted: Tue Dec 27, 2011 9:58 pm
by Baarb
You might also find it interesting to read about why it is people have and continuously maintain certain opinions and attitudes irrespective of what the person on the other side of the table is saying. While such analysis may normally be applied to politics or religion, there's been an increase in the number of investigations into why people have a certain outlook with regard to science, particularly with the divisiveness of climate change etc. Such studies indicate that increased knowledge about something that runs contrary to predisposed opinions may not engender agreement, but rather the opposite, with intelligent and educated people filtering information according to their own cultural biases. I.e. mistrust doesn't entirely stem from a lack of knowledge and cannot be rectified just by providing more of it. This may sound obvious but it's important for understanding how to communicate information in such a way that it makes the desired impact and not just get rebuffed. People dealing with more obvious natural hazards like earthquakes and volcanoes have been looking at this for a long time as if people don't trust you then they won't pay attention when you tell them to do something.

Edit: Here's something vaguely related regarding potential influences on voting behaviour (http://www.cracked.com/article_18847_6- ... n-day.html)

Re: Ngozumpa Glacier meltwater lake hazard (Nepal)

PostPosted: Sun Jan 01, 2012 4:02 pm
by geeyore
This story is a real laugh. I've been up the Ngozumpa Glacier and the Gokyo Valley twice, from Tengboche up past Gokyo Ri.

The entire Gokyo Valley (12+ miles long) was built from the now-receded glaciers that emerge from Cho Oyo and the other surrounding mountains, and carved into the landscape over 100's of thousands of years. To say it's "receding" is academic, like saying "water is wet." Everything is receding since the last Ice Age.

Likewise, the assertion that the 700 meter meltwater lake could "grow to 5 km" seems ludicrous. Based on what? Wouldn't the pressure of the increased water cause new avenues of drainage to be built? And even it it did breach the moraine at the snout, it wouldn't necessarily endanger and Sherpa villages (except maybe Panga and a handful of others down the Dud Kosi), since most of the Sherpa villages are perched high up on the valley walls and hundreds of feet above the riverbeds (where any breaching glacial lakes would go).

This story seems preposterous. Get on Google Earth to look at the scale of these "lakes" against the surrounding terrain, and look at the valleys and villages downstream. Once you do that you might agree that this is utterly false academic alarmism, intended to support further grant applications and to keep the researchers funded for their lengthy trips to the Khumbu Himalaya.

Re: Ngozumpa Glacier meltwater lake hazard (Nepal)

PostPosted: Sun Jan 01, 2012 6:25 pm
by Baarb
Glad to hear from someone with first hand experience in the area. From my view the article is merely reporting on what some scientists are studying as there's a possibility a large amount of water could accumulate and be released en-masse. Presumably the theoretical lake dimensions are based on the basin topography generated by the surrounding mountains and lateral moraines. Perhaps as you say water may migrate out via less dramatic means - there are two rivers going round the terminal(?) moraine at the mouth after all.

However glacial lake outburst floods are a well known phenomena so why not look at it? If that water does burst out dramatically there'll be big changes for people living not only in the immediate area but also far downstream. What kind of erosion takes place with such a large amount of water moving? There could be far reaching consequences. No-one's asking for a billion dollars for some giant engineering project. Understanding something properly requires vigorous research not just speculation. Your average funding panel assessing whether to allocate money requires detailed proposals far above and beyond what gets selectively written about by a journalist.

The article says glaciers are melting due to rising temperatures to explain where the water is coming from as that's what the article is about. Perhaps they could have thrown in snow accumulation rates etc. to offset concerns about wider bias. But again the article is not a commentary on glacial evolution in the area so in a short article there's no need to write about it, nor provide a commentary on the validity of the research. Everyone can go on to read reports from whomever they see fit to learn about the wider issues.