Tag Archives: glaciers

A glacier on Mars

A glacier on Mars

Cool image time! The image on the right, cropped and reduced in resolution, is a Mars Reconnaissance Orbiter picture taken on March 28, 2016 of a glacial flow coming down off of mountains in Mars’ northern mid-latitudes. The mountains are to the south and beyond the bottom right. The flow is to the northwest. The full image can be found here. As noted on the image site,

These flow-like structures were previously called “lobate debris aprons,” but the Shallow Radar (SHARAD) instrument on [Mars Reconnaissance Orbiter] has shown that they are actually debris-covered flows of ice, or glaciers. There is no evidence for present-day flow of these glaciers, so they appear to be remnants of past climates.

Need I say it? This is water, on Mars, and in abundance. Think that this might be good real estate when those first settlers arrive?

Largest glacier calving event ever filmed

An evening pause. Hat tip Phill Oltmann. I had sworn I had posted this already, but now can’t find it on BtB. And even if I have posted it, it is worth watching again. My only comment is that I am baffled by the film’s description of the event as “horrifying.” I don’t find this natural event horrifying, I find it awe-inspiring. It reminds us that the scale of the universe if far far beyond anything we can imagine.

Finding caves on Mars

A new study of pits on Mars has isolated one particular type of pit that has all the features of an Earth-like cave entrance, with a large number located in the regions around the giant volcanoes where evidence of past glacier activity has been found. From the abstract:

These Atypical Pit Craters (APCs) generally have sharp and distinct rims, vertical or overhanging walls that extend down to their floors, surface diameters of ~50–350 m, and high depth to diameter (d/D) ratios that are usually greater than 0.3 (which is an upper range value for impacts and bowl-shaped pit craters) and can exceed values of 1.8. Observations by the Mars Odyssey Thermal Emission Imaging System (THEMIS) show that APC floor temperatures are warmer at night and fluctuate with much lower diurnal amplitudes than nearby surfaces or adjacent bowl-shaped pit craters.

In other words, these pits are deeper with steeper and overhanging walls that suggest underlying passages. They also maintain warmer temperatures at night with their day/night temperatures changing far less than the surface, similar to caves on Earth where the cave temperature remains the same year-round.

The study’s most important finding, from my perspective, was the location of these pit craters.
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The hidden glaciers of Mars

The glaciers belts of Mars

Scientists, using computer models and radar data obtained in orbit, have detected large belts of glaciers in Mars’ upper middle latitudes, buried beneath a layer of dust.

Several satellites orbit Mars and on satellite images, researchers have been able to observe the shape of glaciers just below the surface. For a long time scientists did not know if the ice was made of frozen water (H2O) or of carbon dioxide (CO2) or whether it was mud.

Using radar measurements from the NASA satellite, Mars Reconnaissance Orbiter, researchers have been able to determine that is water ice. But how thick was the ice and do they resemble glaciers on Earth? A group of researchers at the Niels Bohr Institute have now calculated this using radar observations combined with ice flow modelling.

The press release has one typo that is important. The belts appear to be located between 30-50 degrees latitude, not 300-500 (the degree sign became a 0 by mistake).

It is important to recognize the uncertainty of this discovery. Orbital images have seen features that suggest glaciers. The evidence that it is water-ice and that the water-ice is still largely present comes from the computer models. Computer models are notorious for seeing things that end up not being there.

Nonetheless, this result is important. It is further strong evidence that Mars still contains a lot of water locked in its immediate subsurface, where future colonists can mine it and use it to survive and build their homes.

India extends Mangalyaan’s mission by six months

Western slopes of Arsia Mons

Having successfully completed its nominal six month mission and continuing to operate perfectly, ISRO has extended the mission of India’s Mangalyaan Mars orbiter for another six months.

Take a gander at the images the orbiter has been sending down. Quite impressive. The cropped image on the right shows the western slopes of the giant volcano Arsia Mons, with white water vapor hovering above those slopes. (Click on the image for the full resolution version.) The water vapor is significant because scientists believe that this region once had many glaciers, and that much of that water is still present and trapped below the surface as ice, possibly in many of the caves that are there. The vapor’s presence, a routine occurance here, strengthens this theory.

Glaciers on Mars!

A geological study of orbital images of Gale Crater has led scientists to conclude that the crater was once covered in glaciers.

To carry out the study, the team has used images captured with the HiRISE and CTX cameras from NASA’s Mars Reconnaissance Orbiter, together with the HRSC onboard the Mars Express probe managed by the European Space Agency (ESA).

Analyses of the photographs have revealed the presence of concave basins, lobated structures, remains of moraines and fan-shaped deposits which point to the existence of ancient glaciers on Gale. In fact they seem to be very similar to some glacial systems observed on present-day Earth. “For example, there is a glacier on Iceland –known as Breiðamerkurjökull– which shows evident resemblances to what we see on Gale crater, and we suppose that is very similar to those which covered Gale’s central mound in the past,” says Fairén.

This is not the first place on Mars where scientists believe glaciers once flowed. The northwestern slopes of Arsia Mons, one of Mars’s giant volcanoes in the Tharsis Bulge, is also believed to have once harbored glaciers.

For the past four years the glaciers in Glacier National Park have stopped shrinking.

The uncertainty of science: For the past four years the glaciers in Glacier National Park have stopped shrinking.

“We had this sort of pause,” Fagre said of shrinking at Sperry Glacier and, by extrapolation, other glaciers. “They pretty much got as much snow as they needed.” Sperry covered 0.86 square kilometers in 2005, 0.83 in 2009 and 0.82 in 2013, illustrating the “pause” in its retreat as there was a 0.03 square kilometer loss from 2005 to 2009, but only 0.01 in the last four years, from 2009 to 2013, Fagre said.

The article spends a lot of time talking about how the shrinkage is about to resume and the glaciers are certain to disappear, but this pause in glacier shrinkage corresponds nicely with the 17 plus year pause in warming that has been going on.

And then there’s this: Great moments in climate forecasting.

And this, also from Steve Goddard: In 1971 the world’s top climate scientists said fossil fuels would cause an ice age by 2020.

I especially like the quote from the last article, where these experts say that there is “no need to worry about the carbon dioxide fuel-burning puts in the atmosphere.” These are the same experts who have have spent the past three decades since 1988 telling us that CO2-caused global warming was going to kill us all.

Are the glaciers in the Himalayas shrinking? A third paper published today falls between one study that said no and another that said yes.

The uncertainty of science: Are the glaciers in the Himalayas shrinking? A third paper published today falls between one study that said no and another that said yes.

The new estimate raises further questions about satellite and field measurements of alpine glaciers, and ”will set the cat among the pigeons,” says Graham Cogley, a remote-sensing expert at Trent University in Peterborough, Ontario. … Although the ICESat results show twice as much ice loss as the re-interpreted GRACE data, this figure is still three times lower than regional losses estimated on the basis of field studies.

A new study suggests that the glaciers in the Himalayas are shrinking, with different regions shrinking much faster than others.

The uncertainty of science: A new study suggests that the glaciers in the Himalayas are shrinking, with different regions shrinking much faster than others.

This study both supplements and contrasts other work which suggested that the western Himalayan glaciers were not shrinking.

It is interesting that the article above does not give any specifics on the rate of shrinkage, other than to say it is getting faster in some areas. Instead, the focus of this work centers more on the discovery that India’s monsoon winds have a significant influence on glacier growth or retreat.

A new study has found that the glaciers of Greenland are not behaving as predicted.

The uncertainty of science: A new study has found that the glaciers of Greenland are not behaving as predicted.

In northwestern Greenland, for example, where most of the glaciers move relatively quickly and flow directly into the sea rather than ending on land, average speed jumped by 8% between 2000 and 2005 and rose another 18% from 2005 to 2010. Nevertheless, the researchers report online today in Science, the glaciers in this region showed no uniform pattern of acceleration. About one-third flowed at the same rate throughout the decade, one-fourth slowed during the interval, and about 15% slowed during the first half of the decade and then surged from 2005 to 2010.

Similarly, many of the individual glaciers in southeastern Greenland don’t follow the region’s overall trend. Although the average speeds for these glaciers increased by 28% over the decade, substantial accelerations by some glaciers were balanced by considerable slowing by others. About 43% of the glaciers in the region sped up between 2000 and 2005, but around 25% slowed down by more than 15% from 2005 to 2010.

In other words, if there is any warming, it hasn’t manifested itself in a predictable manner in the glaciers of Greenland. In fact, the data above suggests instead that if there has been any warming, it either has been far less than predicted, or has had relatively little influence on the Greenland ice sheet.

The Himalayas and nearby peaks have lost no ice in past 10 years, study shows

The uncertainty of science: New satellite data shows that the glaciers in the Himalayas have lost no ice in past 10 years.

The scientists are careful to point out that lower-altitude glaciers in the Asian mountain ranges – sometimes dubbed the “third pole” – are definitely melting. Satellite images and reports confirm this. But over the study period from 2003-10 enough ice was added to the peaks to compensate.

Is this further confirmation that global warming stopped ten years ago? Not really. As the report notes, the time period is too short to establish a clear trend. Moreover, this study only deals with the Asian glaciers, which is also too small a sample for any firm conclusions.

Nonetheless, the data does illustrate once again how complex and uncertain the study of the Earth’s climate is. Anyone who claims we know what is really happening is either refusing to look at all the data or is simply lying.

The state of the Himalayan glaciers

A new study of the glaciers of the Himalayas by the Indian Space Research Organization and the Geological Survey of India has found that, based on satellite data, 2184 were retreating, 435 were advancing, and 148 showed no change.

It is refreshing that the scientists and politicians involved in India refused to cite global warming as a cause, referring instead to the “natural cyclic process”. As India’s former environment minister Jairam Ramesh noted, “There is no doubt that the general health of the Himalayan glaciers is worsening, but the truth is incredibly complex.”

New research finds that the Himalayan glaciers are not melting

New research finds that the Himalayan glaciers are not melting. Key quote:

The new study by scientists at the Universities of California and Potsdam has found that half of the glaciers in the Karakoram range, in the northwestern Himlaya, are in fact advancing and that global warming is not the deciding factor in whether a glacier survives or melts.

The last part of the above quote, on global warming, is almost certainly an overstatement of what we do or don’t know. Warming will cause glaciers to melt, but how much and when are factors that are still not understood. Moreover, we are still not sure how much warming has even occurred.