Blue Lakes in Antarctica and Lies from the Independent
By Paul Homewood
Put the Independent and Chris Mooney together, and what do you get? Alarmist drivel!
In a new study, scientists who study the largest ice mass on Earth – East Antarctica – have found that it is showing a surprising feature reminiscent of the fastest melting one: Greenland.
More specifically, the satellite-based study found that atop the coastal Langhovde Glacier in East Antarctica’s Dronning Maud Land, large numbers of “supraglacial” or meltwater lakes have been forming – nearly 8,000 of them during summer months between the year 2000 and 2013. Moreover, in some cases, just as in Greenland, these lakes appear to have then been draining down into the floating parts of the glacier, potentially weakening it and making it more likely to fracture and break apart.
This is the first time that such a drainage phenomenon has been observed in East Antarctica, the researchers say – though it was previously spotted on the warmer Antarctic Peninsula and was likely part of what drove spectacular events there like the shattering of the Larsen B ice shelf in 2002.
When it comes to East Antarctica, however, “that’s the part of the continent where people have for quite a long time assumed that it’s relatively stable, there’s not a huge amount of change, it’s very, very cold, and so, it’s only very recently that the first supraglacial lakes, on top of the ice, were identified,” said Stewart Jamieson, a glaciologist at Durham University in the UK and one of the study’s authors.
The study was led by Emily Langley of Durham, who worked along with Jamieson and Chris Stokes from her university and Amber Leeson of Lancaster University. Their findings were recently published online by Geophysical Research Letters.
The research raises concern, for the following reason: Mounting evidence suggests one reason that Greenland has been melting so fast lately is precisely these kinds of lakes. In the summer as air temperatures warm, lakes form on top of the ice sheet, and on its finger-like glaciers that extend outwards into deep ocean fjords.
These lakes can then suddenly disappear all at once, or flow into rivers that drain into the ice below, lubricating the ice and helping to increase the lurch forward of glaciers. Sometimes, researchers have even been able to document fresh water flowing outward directly into the sea from the base of a glacier. That injection of cold fresh water into salty water can then create tornado-like underwater flow patterns at the submerged glacier front that cause further ice loss.
In the new study, Langley and her colleagues find large numbers of lakes forming atop Langhovde Glacier, both inland from, and outward from, the so-called “grounding line,” which is where the marine glacier touches the seafloor far below the ice surface. Past the grounding line, the glacier’s ice begins to float and forms an ice shelf, extending out across the surface of the ocean.
The occurrence of these lakes was strongly related to surface air temperatures – they formed when temperatures rose above zero Celsius, or, above freezing, and formed most frequently in the summer of 2012-2013, which saw 37 days with temperatures above the freezing point.
“What we find is that the appearance of these lakes, unsurprisingly, is correlated directly with the air temperature in the region, and so the maximum number of lakes, and the total area of the lakes, as well as the depth of the lakes, all of these things peak when the air temperatures peak,” said Jamieson.
The study found in particular that atop the Langhovde ice shelf, lakes not only formed but appeared to sometimes drain downward, as rapidly as in five days in one case (which is considerably slower than the fastest drainage events in Greenland).
This raises the concern that these events could possibly be weakening the ice shelf by widening or exploiting fractures within it. But Jamieson said the study could not prove that, in part because it is much harder to observe the consequences of lake draining events in Antarctica than it is in Greenland.
Apparently it has not crossed Looney’s mind that scientists have not actually looked for these melt lakes before, or that they might be perfectly natural and common events.
This is the paper he refers to:
The authors make it clear in the Introduction that no prior analysis of this phenomenon has been done before:
Here we present the first quantitative multiyear data set of lake evolution and distribution on an East Antarctic outlet glacier for the period between 2000 and 2013.
They find that ice melt is, unsurprisingly, strongly correlated to surface air temperature:
Unsurprisingly, there is a strong correlation between supraglacial melt and surface air temperature (Figure S1), which determines the amount of energy available for melt each year [Bartholomew et al., 2010]. Lake initiation and evolution is directly correlated with surface air temperature and, more specifically, the number of positive degree days.
But what are the temperature trends in Dronning Maud Land?
There are two stations used by GISS located there, Neumayer and Novolazarevskaya. Neither show any warming trends on an annual basis:
But, more importantly, what has been happening during summer months?
Again, there is no evidence that summers are getting warmer. Indeed, the opposite appears to be true, with some of the warmest summers back in the early 1990s.
To be fair, the authors never attempted to claim that ice melt was getting worse. They have simply carried out an academic exercise.
Unfortunately, as is usually the case, the alarmist media jumps on any study like this to convince the public that we are all going to die.
The reality is much more mundane.
Even in Antarctica, there are occasionally days when the sun comes out, and temperatures creep above zero, causing small amounts of ice to melt. This is called weather, and has no doubt been occurring for millennia, during which time the Antarctic’s ice sheet has not collapsed.
Nothing in the temperature record suggests this will change in the immediate future.