Search Results for Tag: Sea level
Greenland earthquake and tsunami – hazards of melting ice?
Following the news over the weekend with a trip to Greenland this summer at the back of my mind, my attention was immediately caught by reports of a tsunami and earthquake in Greenland. Four people were reported missing. Buildings had been swept away, including the power station on the island of Nuugaatsiaq. Greenland is not the first place that comes to mind in connection with earthquakes and tsunamis. But in fact they are not as rare as you might think.
The cause of the weekend’s event is still unclear. But a tweet from the Greenland Climate Research Centre links to an article in the Washington Post from June 25 2015:
The article reports on a paper published in the journal Science at that time by researchers from Swansea University in the UK, the Lamont-Doherty Earth Observatory at Columbia University and several other institutions. It says the loss of Greenland’s ice can generate “glacial earthquakes”.
“When vast icebergs break off at the end of tidal glaciers, they tumble in the water and jam the glaciers themselves backwards. The result is a seismic event detectable across the Earth”.
Worrying reading indeed, as GCRC wrote in their tweet.
The Washington Post article quoted Meredith Nettles from Columbia, one of the co-authors.
She specifically mentions the tsunami effect:
“The tsunami is caused because the iceberg has to move a lot of water out of the way as it tips over”.
Too early to say
I have been trying to find more information on what the experts think caused this weekend’s particular event. So far, there is no clarity. But the GCRC tweet with link to the Washington Post article seems to indicate they think it could be ice-related.
Another theory is that the quake and tsunami were caused by a landslide. The news agency DPA says the Geological Survey of Denmark and Greenland are still trying to determine the cause of the tsunami.
“Initially, geologists believed it was triggered by an earthquake, but another theory blamed a large landslide from one of the mountains on the fjord system”.
It seems the Danish Arctic Commando published images showing signs of an extensive landslide.
“Tsunamis and large waves at times affect Greenland’s coasts, but, according to the Geological Survey, they are usually caused by landslides and the breaking off of ice from melting glaciers”, the agency writes.
DPA earlier noted that the Danish earthquake authority GEUS had recorded a 4.0 quake.
Warning from Greenland ice cores
One way or other, the weekend tsunami is unlikely to allay anxiety about the effects of rapidly melting substantial quantities of ice.
And a study just published by Germany’s Alfred-Wegener-Institute (AWI) provides more food for thought about human-induced changes to our climate. It indicates that the gradual nature of the changes we are making to the CO2 concentration in the atmosphere is no guarantee that the resulting climate change will also be gradual. On the contrary. Computer models based on information from ice cores from Greenland show that in high latitudes of the northern hemisphere, there were abrupt changes in climate, which the scientists attribute to a gradual increase in CO2.
During the last ice age, they say that the influence of atmospheric CO2 on the North Atlantic Current within a few decades led to an increase in temperature of up to 10 degrees Celsius in Greenland. The study, published in the journal Nature Geoscience, by scientists from AWI and the University of Cardiff shows that in recent earth history, there have been situations when gradual increases in CO2 concentrations at what are known as “tipping points” led to abrupt changes in ocean circulation and climate.
Sudden warm age on the horizon?
Lead author Xu Zhang says the study is the first to prove that a gradual increase in CO2 can set off very rapid warming, based on interactions between ocean currents and the atmosphere.
The authors also show that the rise in CO2 is the main cause of chances in ocean currents during the transition from an ice age to a warm period.
Of course, they add, the framework conditions today are different from those during an ice age, so it is not possible to say the rise in CO2 will have similar effects in future.
But they say they can definitely show that there were abrupt climate changes in Earth’s history, which can be traced back to continual rises in CO2 concentrations.
Reason enough for concern to people living on the coast of Greenland – not to mention the rest of us, given the key role the world’s biggest island, with the biggest freshwater mass in the northern hemisphere sitting on top of it in the form a giant ice sheet, plays in influencing climate and sea levels around the globe?
DateJune 19, 2017 | 3:12 pm
TagsArctic, AWI, Climate, CO2, earthquake, Emissions, glaciers, Greenland, ice, ice age, research, science, Sea level, tsunami
Working for an international broadcaster which has Africa as one of its key target groups, I often find it difficult to interest some of my colleagues in what is happening in the Arctic. So my attention was caught instantly when I came across an article by Chelsea Harvey in the Washington Post: A climate chain reaction: Major Greenland melting could devastate crops in Africa.
DateJune 9, 2017 | 11:17 am
Tags#saveOurOceans, Africa, Arctic, Climate, Greenland, ice, ocean acidification, Renewables, research, science, Sea level, UN talks, Warming
Arctic sea ice: is the minimum maximum the new normal?
If you blinked, you might have missed it. The confirmation came this week that the Arctic sea ice reached yet another all-time low this past winter. It came and went, without too much ado.
Maybe the excitement was just past. The maximum extent was actually reached on March 7th, but of course you can only be sure it is really not going to spread any further once it has definitely been retreating for some time with the onset of spring.
I was waiting for the NSIDC confirmation, but not with any doubt in my mind that it would tell us officially the maximum for this season would be a minimum.
The danger is a “so what?” kind of reaction, or resignation, with the feeling that nothing short of some kind of unprecedented experimental geo-engineering could save the Arctic summer sea ice in the coming years, as the world continues to warm.
Lowest on record
The National Snow and Ice Data Center (NSIDC), part of the Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder, and NASA confirmed this week that Arctic sea ice was at a record low maximum extent for the third straight year.
It reached the maximum on March 7, at 14.42 million square kilometers (5.57 milion square miles). Since then, it has started its annual decline with the start of the melt season. Some time in September it will reach its minimum.
This year’s maximum is the lowest in the 38-year satellite record. NSIDC scientists said a very warm autumn and winter had contributed to the record low maximum. Air temperatures were 2.5 degrees Celsius (4.5 degrees Fahrenheit) above average over the Arctic Ocean. Against the background of overall warmth came a series of “extreme winter heat waves over the Arctic Ocean, continuing the pattern also seen in the winter of 2015”, NISDC said in a statement.
The air over the Chukchi Sea northwest of Alaska and the Barents Sea north of Scandinavia was even warmer, averaging around 9 degrees Fahrenheit (five degrees C) above the norm.
NSIDC director Mark Serreze said in his statement: “I have been looking at Arctic weather patterns for 35 years and have never seen anything close to what we’ve experienced these past two winters.”
The winter ice cover was also slightly thinner than that of the past four years, according to data from the European Space Agency’s CryoSat-2 satellite. Data from the University of Washington’s Pan-Arctic Ice Ocean Modeling and Assimiliation System also showed that the ice volume was unusually low for this time of year.
Record summer melt ahead?
“Thin ice and beset by warm weather – not a good way to begin the melt season,”, said NSIDC lead scientist Ted Scambos.
A low maximum does not necessarily mean the minimum to be measured in September will also be a record low, as it depends on summer weather patterns. But Julienne Stroeve from NSIDC and professor of polar observation and modeling at the University College London said “Such thin ice going into the melt season sets us up for the possibility of record low sea ice conditions this September”.
“While the Arctic maximum is not as important as the seasonal minimum, the long-term decline is a clear indicator of climate change”, said Walt Meier, a scientist at the NASA Goddard Space Flight Center Cryospheric Sciences Laboratory and an affiliate scientist at NSIDC. Iceblog readers might wonder if that is stating the obvious, but given the attitudes of the US administration, you can’t take anything for granted.
The September sea ice measurements began to attract attention in 2005, when the ice extent first shrank to a record low over the period of satellite observations. It broke the record again in 2007 and in 2012. There used to be little interest in the maximum extent of the Arctic sea ice at the end of winter. I can remember reading with concern and writing a piece about the maximum extent also reaching a record low in 2015.
“Arctic sea ice extents have followed a steady downward trajectory since the start of the 21st century – at the same time global temperatures have reached new record highs. Betides setting multiple record low summertime minimum extents, Arctic sea ice began to exhibit a pattern of poor winter recovery starting around 2004.”
Living on thin ice
I remember an expedition to Alaska in 2008, when locals at Barrow told me about their personal experiences of the sea ice becoming thinner and less dependable. Some years later I heard similar reports from people in Greenland, who were selling their sled dogs and buying boats in preparation for changing from ice to open water fishing. The data backs them up.
Yereth Rosen, writing for Alaska Dispatch News, draws attention to the problems of continuing to collect that data. She quotes NSIDC’s Serreze:
“Just how well the center will be able to track sea ice in the future remains unclear. No new satellite is expected to be in place until 2020, and there are concerns about potential interruptions in the record that goes back to 1979… We’re at a situation where the remaining passive microwave instruments up there are kind of elderly. If we have satellite failures, we could lose that eye in the sky”.
Now there is a worrying thought.
Against the background of budget cuts proposed by the Trump administration, that – to put it mildly – does not regard tracking climate change as a high priority – scientists are understandably worried about the future of scientific research on climate and environment related issues.
Method in the madness?
Without reliable continuous satellite data, it would be much harder to track how climate change is affecting the polar regions, the ocean and our planet in general. This may well be the intention of climate-change deniers behind the scenes. But climate change itself will not go away – and the impacts will be increasingly evident.
Tim Ellis, writing for Alaska Public media, quotes Serreze as saying the polar ice cap will not last long if the region continues to warm at this rate.
“We are on course sometime in the next few decades, maybe even earlier, to have summers in the Arctic where, you go up there at the end of August, say, and there’s no ice at all.”
“The view from space in the fall of around 2040” , he went on – assuming we still have satellites to take the pictures – “will be of a blue Arctic Ocean, aside from some scattered icebergs and clusters of pack ice”.
I don’t know about you, but I find that a rather depressing thought.
Implications for the rest of the globe
Andrea Thompson, for Climate Central, writes “even in the context of the decades of greenhouse gas-driven warming, and subsequent ice loss in the Arctic, this winter’s weather stood out.”
She also reminds us of the global impacts of a warming Arctic and decline in sea ice:
“The Arctic was one of the clear global hotspots that helped drive global temperatures to the second- hottest February on record and the third-hottest January, despite the demise of a global heat-boosting El Nino last summer.”
This week the UN’s World Meteorological Organisation (WMO) said 2016 had been the hottest year ever recorded, and that the record-breaking heat had continued into 2017, sending the world into “truly uncharted territory”.
“The dramatic melting of Arctic ice is already driving extreme weather that affects hundreds of millions of people across North America, Europe and Asia, according to emerging research”, Damian Carrington writes in the Guardian.
On March 15th, Carrington published an article entitled “Airpocalypse smog events linked to global warming”, referring to extreme smog occurrences in China.
Optimism – the only way to go?
This week I interviewed German oceanologist and climatologist Mojib Latif. I wanted to find out whether the highly unusual extreme rainfall and flooding happening in Peru could be explained by natural cycles or was likely to be a climate change impact which could reoccur. You can read the interview here or listen to it on my Living Planet show this week online or on soundcloud.
The professor stressed that the scientists are baffled, because it is not really the time for an el Nino, although this seems to be a “coastal el Nino”, driven by exceptionally warm water off the coast. Of course he is reluctant to attribute any single event to climate change. He stated unequivocally, though, that the warming of the ocean worldwide was absolutely inexplicable without anthropogenic CO2 emissions, that this is all in line with climate models and that we should all be preparing for an increasing number of increasingly extreme weather events, as the world warms.
He says the governments of the world (apart perhaps from the new US administration) are in no doubt that climate change is happening and they need to halt it. But they have so far failed in their attempts.
When I asked Professor Latif if he still felt optimistic, he told me we really had no other choice. While critical of the lack of government action, he is convinced the world will realize that renewables are ultimately far superior to fossil fuels and will ultimately prevail. The question is whether that will happen in time. As far as the Arctic summer sea ice is concerned, I have to go with a Scots expression: “A hae ma doots”.
DateMarch 24, 2017 | 2:31 pm
TagsAlaska, Arctic, Barrow, China, Climate, el Nino, Emissions, Greenland, ice, IFM-Geomar, Living Planet, polar bears, research, science, sea ice, Sea level, Warming, weather
Greenland ice holds Cold War peril
It sounds like something from a science-fiction novel or a disaster movie. A hidden city under ice, housing 200 people, complete with hospital, cinema, church and research labs – and powered by a mini nuclear reactor. In fact it is reality and lies below the ice of north-west Greenland. The building of Camp Century was started in 1959, by US army engineers.
The camp was abandoned when the glacier above turned out to be shifting much faster than expected in 1967, threatening to crush the tunneled base below. Pollutants including PCBs, tanks of raw sewage and low-level radioactive coolant from the nuclear reactor were left behind.
“When the waste was deposited there, nobody thought it would get out again”, William Colgan, an assistant professor in the Lassonde School of Engineering at York University in Canada, told AFP. Colgan is co-author of a study published in August: Melting Ice could release frozen Cold War-era waste.
Unfortunately, recent research results have told us that the ice island of Greenland is melting even faster than previously thought. A new study published this week in the journal Science Advances using GPS to help estimate how much Greenland ice is melting, comes to the conclusion it is losing around 40 trillion pounds more ice a year than scientists previously thought. That is around 7.6 percent of a difference.
GPS maps past and future ice loss
Most measurements of ice sheet loss use a satellite that measures changes in gravity, and uses computer simulations to calculate the weight loss of ice. But co-author Michael Bevis of Ohio State University told the news agency AP that a portion of the mass calculated by the satellite as ice mass, is actually made up of rocks, which rise up to replace the ice when it goes. This distorts the picture, giving the impression there is more ice than there actually is.
The new study also reconstructs ice loss from Greenland over millennia and comes to the conclusion that it is the same parts of Greenland – the north-west and the south-east – which are losing most ice today as in the distant past. The authors say this means the rapid ice lost we have seen over the last 20 years is part of a long-term trend, being exacerbated by climate change. Damian Carrington in the Guardian, quotes Christopher Harig from the University of Arizona as an independent scientist not involved in the study:
“The new research happening now really speaks to the question: ‘How fast or how much ice can or will melt by the end of the century?’ As we understand more the complexity of the ice sheets, these estimates have tended to go up. In my mind, the time for urgency about climate change really arrived years ago, and it’s past time our policy reflected that urgency.”
Frozen hazards await release
Coming back to Camp Century – here, and elsewhere in the “frozen North”, a lot of the perils once locked safely inside an icy safe are now lurking ready to emerge when the time comes. Colgan led a study published in August in the journal Geophysical Research Letters, which found that higher temperatures could eventually result in toxic waste from the base being released into the environment. By 2090 the amount of ice melting may no longer be offset by snowfall, meaning the toxic chemicals could start leaking into the environment, the study found. Even before that, fissures in the snow could lead to melt water seeping into the crushed tunnels, currently located just 35 metres below the surface.
This is just one spectacular example of a problem that is widespread across the Arctic. Anthrax spores, nuclear waste from subs and reactors … and these are only the human-made dangers. The permafrost is sometimes described as a “time bomb”, with masses of methane and carbon stored as part of natural processes coming to the surface as the world warms.
The news story on AFP centres on who is responsible for cleaning up the pollution from the under-ice camp. The USA and Denmark signed a treaty to permit the construction of Camp Century, code-named “Project iceworm”. Officially, it was to provide a laboratory for Arctic research projects. AFP says it was also home to a “secret US effort to deploy nuclear missiles”. Maybe it was lucky the project had to be abandoned in 1967. But the legacy remains in the form of the nuclear waste left buried under the snow when the reactor was removed.
We have the technology, but…
Study author William Colgan believes the physical logistics of decontaminating the site may not be the biggest challenge involved in all of this. “The environmental hazard is relatively small and far away and there are only a few native towns close by”, AFP quotes.
I was shocked by this statement, which seems to imply that we don’t need to worry about “a few native towns”. I hope I have misunderstood him here. Surely the lives of these small communities should have top priority?
But I can follow his reasoning that establishing which country is responsible for making good the damage is harder than the actual physical clean-up. (He also mentions that the USA and Denmark have experience in similar clean-up operations around the Thule air base, which is around 240 toxic messes or worrying that all our technology cannot prevent destruction of the fragile Arctic environment if we carry out risky operations?)
A worrying precedent
Colgan says the dispute over responsibility “could help set a precedent for other conflicts arising from climate change”. Now that is a very worrying prospect. Unfortunately, it is also a highly realistic one.
When it comes to accepting responsibility for the climate change which is speeding up the melting of Greenland’s huge ice-sheet – and taking action to halt it by abandoning fossil fuels – conflicts are virtually pre-programmed.
When it comes to the costs of dealing with the migration of people forced out of their homes by sea-level rise, flooding, drought, and of ensuring progress for developing countries without climate-harming fossil fuels, states are unlikely to be queuing up to foot the bill.
DateSeptember 26, 2016 | 12:47 pm
TagsArctic, Camp Century, Climate, Cold War, Emissions, Greenland, ice, nuclear, permafrost, research, science, Sea level, toxic waste, USA, Warming
The Rio games have come to an end. Summer is drawing to a close here in Germany. It feels more like autumn today, cool with heavy rainshowers. But there’s a heatwave around the corner after what most people agree has been a very strange summer.
July followed in the record-breaking trend of the earlier months of the year, being the hottest month ever recorded on the planet.
DateAugust 22, 2016 | 1:46 pm
TagsArctic, Climate, CO2, Emissions, glaciers, Greenland, ice, methane, permafrost, sea ice, Sea level, Warming, Zackenberg