Happy holidays!!

Thank you all who have logged on in the days since my last post! I'm on an adventure that turns out to have even fewer internet stops than I had anticipated, but have some fantastic geology to share when I return.

Meanwhile, everyone, I appreciate your interest in this site, and Happy New Years to all!

Winter storms in Europe and the Arctic Oscillation

From the Arctic Climatology and Meteorology Education Center
Figure there courtesy of J. Wallace, University of Washington

AO index from 1950 to present
from
National Weather Service
Climate Prediction Center

For several days now flights have been cancelled into and out of many of Europe's major airports.  London's Heathrow and Gatwick have been amongst the hardest hit, Paris Charles de Gaulle is canceling a quarter of the flights today, and Frankfurt is canceling at least 500 of a planned 1300 flights. Airlines are claiming that they haven't seen storms like this in 20-30 years.  What is going on?

Weather in Europe is strongly controlled by a natural phenomenon called the Arctic Oscillation. This is a pattern of pressures over the Arctic.  In a so-called "positive phase" (illustrated on the left of the figure at the upper right) the pressure over the polar region is low and higher pressure in the midlatitudes drives ocean storms toward the north.  In this phase, Alaska, Scotland and Scandinavia have wetter than normal weather, and the US west and the Mediterranean have drier conditions. Frigid winter air doesn't extend as far into North America as usual, which keeps much of the US east of the Rocky Mountains warmer than normal, but Greenland and Newfoundland are colder than usual. Since the 1970's the oscillation tended to be in this phase, which you can see by the dominance of red on the graph to the right.

In the "negative phase" there is relatively high pressure over the polar region and lower pressures in the midlatitudes, but the difference in the pressures are small, that is, the pressure systems are weak. We are now in a negative phase.  The Arctic is warmer than average, whereas parts of the midlatitudes are colder than normal.  The Arctic Oscillation especially affects patterns over Europe, and is the cause of the current blustery weather as well as that in December a year ago. Ironically, the Arctic Oscillation Index went strongly negative just about the time that the 2009  Copenhagen Climate Conference started, causing unexpectedly cold weather there!

For my European friends, stay warm and safe during these holidays!

Book Review: The Planet in a Pebble

Photo Oxford University Press

The Planet in a Pebble: A Journey into Earth’s Deep History

By Jan Zalasiewicz

Oxford University Press, 234 pp.

2010

ISBN 978-0-19-956970-0

$27.95 US

The Planet in a Pebble tells the story of the history of the earth as it can be inferred by a geologist thinking about a pebble. In this sense, the book is evocative of Thomas Huxley, who did the same in 1868 using a piece of chalk. Zalasiewicz, however, uses every method available in the 20^th and 21^st centuries, from the scale and style of field work to the microsopic detail provided by state-of-the art laboratory analyses now available to tell the story. In popular jargon, this is forensic geology. The intended audience appears to be the scientifically literate and interested. Given the state of science literacy in the U.S., this will, unfortunately, be a small audience here.

Zalasiewicz has studied the Welsh slate, a rock that had the “alas, reputation of being wet, grey, and monotonous,” for much of his career with the British Geological Survey, and is superbly qualified to tell this tale. He is the author of “The Earth After Us”, speculations on the state of the planet after humans are no longer a part of it. He is also a gifted writer who clearly loves the language. Two paragraphs from the prologue capture both the essence and the style of the book:

“It is just an ordinary pebble. One of millions that wash backwards and forwards on the world’s shorelines, or pile up on riverbanks or perhaps line your garden path. Yet that pebble, like its myriad kin, is a capsule of stories. There are countless stories packed tightly within that pebble, more tightly than sardines in the most ergonomic of tins.

The size of this story-capsule is deceptive. These stories are gigantic, and reach realms well beyond human experience, even beyond human imagination. They extend back to the Earth’s formation—and then yet farther back, to the births and deaths of ancient stars. Something of the Earth’s future, too, may be glimpsed beneath its smooth contours. Battle, murder, and sudden death are there, and ages of serenity too, and molecular sleights of hand that would make a magician gasp; there are extremes of cold in those stories. And also temperatures that far surpass the heart of our sun.”

Zalasiewicz says that humans love stories, are born storytellers, and he successfully tells a story here. Beginning with a chapter entitled “Stardust,” he introduces the concepts of atomic matter from which his pebble is built, and then moves on to briefly introduce the current structure of the earth’s interior before getting to the core of the book: minerals and sedimentary rocks. How were the Welsh slate pebbles actually formed and how do these pebbles relate to the “deep time” of geology that goes much further back in time than the age of the slate itself (410-570 million years)? He ends with speculations on the future of the pebble, and a nice suggested “further reading” list.

Along the way, he does a nice job of conveying the feeling about what the profession of geology is like, and the nature of the techniques that we use.

My criticisms of the book are truly minor. I was puzzled (as were several colleagues to whom I showed the book) why the front cover had brightly colored pink, grey and white rocks, perhaps even granites or sandstones(?) when the whole theme was the “wet, grey, and monotonous” shale. The back cover and chapter photos certainly show that there are plenty of beautiful grey rocks that could have been featured! If meant to challenge the reader to think about the story in every pebble, it’s too subtle, but perhaps it helps get people to pick up the book because it's more attractive than a collage of grey rocks? I also think that putting the List of Plates right in the front of the book immediately after the Table of Contents was a mistake. These captions are full of technical terms (graptolites, monazite, “tectonically thickened barrel-like mica”) that will discourage any casual reader who is not a geologist from turning more pages. A figure showing the terms used for the geologic time periods would have been helpful.

At this time, when there is such a need for science communication, Zalasiewicz’s contributions and talent are most welcome. I recommend this book not only for the well-told story of earth history, but also for the beautiful writing.

Followup on Pakistan floods

The  floods in Southern Pakistan before (left) last summers major flooding, during it (middle) and this month (right).
Photo collage originally from Modis instrument on NASA's Terra satellite.  This collage from Geology.com.

The NASA image of the September frame, with sites labeled for reference.

When I was first starting this blog, a crisis was developing near the border with China at Attabad, with the potential failure of a landslide dam (here's one blog that I wrote).  These floods that caused the crisis at Attabad moved like a wave from north to south, culminating with flooding near the delta at the bottom of the images (original, higher-quality images are available here). In these images, water ranges in color from light blue to navy; vegetation is bright green--even if it is sparse.  Bare land is beige to red. Clouds are pale green.  Here's another update as of 12/09/10.

The caption released with the images points out several places affected by the floods.  Around Sukkur on the inland side, an irrigation network had supported agriculture.  Floodwaters overwhelmed a dam north of here, creating a flood that inundated this area and dumped water into the preexisting Manchhar Lake.  There is no outlet for this lake, and so the flood waters have sat on the agricultural land for months. Even though the size of the lake has diminished during the autumn months, it is still larger than prior to the 2010 floods (compare the left and right images). Around the coast at Thatta, there is also evidence for lingering damage, with pockets of water remaining in areas which were dry in 2009. Such areas, if stagnant for long, become foci for disease.

The floods themselves were a disaster. The lingering effects such as the drowning of agricultural lands, disease, and dislocation of people from the flooded area are referred to as the "disaster within the disaster". We see how all of these can contribute to political instability in the events that are evolving in Haiti in the wake of the major earthquake there this year.

1859 Solar Superstorm

"The Northern Lights"
Frederick Church, American painter
painted in the 1960's,
perhaps inspired by the 1859 superstorm

I had an earlier post on a the current solar activity in the context of a concern of Newt Gingrich who has made it a political issue. NASA has an interesting blurb today that lays out some of the concerns, and this blog is a summary of that article which puts "The Great Solar Superstorm of 1859" in perspective of the events of the last half of the 20th century.  It includes the following collage of events from past descriptions of superstorms:

"She ran screaming down the street, unable to contain her terror as night was turned into hideous crimson daylight…communications networks failed and equipment burst into flame…a bustling city lost power, trapping thousands of people inside elevators…satellites malfunctioned and in an instant millions of people lost touch with critical services, doctors and children."

From the NASA report cited. Based
on the work of Smart et al.

The 1859 superstorm lasted for 10 days, and is deemed one of the most spectacular solar storms in the past 450 years.  The basis for saying this comes from work by Michael Smart and colleagues who discovered that nitrate concentrations in trapped gases in the Greenland and Antarctic ice crystals rise and fall with solar activity. The graph to the right shows atmospheric nitrate (NOx) abundances from Galileo's time to the present, with the 1859 event highlighted in red.  The article calls attention to the time period during which the satellite industry has based their estimates of "worst case" scenarios: the last part of the 20th century in which there were only two major events, August 4, 1972 and March 1991.  In contrast, since 1561, there have been 19 events more intense than these two, with an average (though nonuniform) interval of 23 years. "The current 40-7ear-0eriod has been the least productive in generating large [events] as far back as 1670 during the Maunder Minimum.  If you wanted to build satellites that endure the rigors of the space environment, Cycle 23 [our last one] and some of the severe storms during the last 50 years, were probably the wrong examples to use as a 'tall pole' for how bad things can get." (I need to update my NASA jargonese, never heard the 'tall pole' analogy before; wonder if goes with their newly discovered sense of drama (the collage above, and sunspot description mentioned below!).


Nevertheless, during Cycle 23, there were satellite outages and losses totaling nearly $3 billion, and commercial satellites collectively lost about 3 years of lifespan at an estimated eventual cost of tens of billions in lost profit.  There were also several near-misses with US electrical grid blackouts.  Those in Quebec who remember the day that the power grid went down in March in Quebec, or those of us who are here in a deep freeze in the midwest this December shudder (literally) at the thought of a length power outage.


If Cycle 24 (the one we have now begun) were to have such a storm, it would be close to sunspot maximum, sometime between 2010 and 2012, likely in March or September during the Equinoxes. If astronomers notice a "large, angry-looking" sunspot (when did NASA start writing poetically?!!) crossing the solar meridian, time to look out.  It is predicted that all satellites on the daylight side of Earth would be blacked out by an intense blast of X-rays and energetic particles.  The X-rays would destroy the D-layer and cause shortwave blackouts; ozone would be depleted by 5-10% causing a spike in skin cancer events.  Auroras would dazzle us around the world. Computer systems on earth would crash as the integrity of their binary information systems is compromised.  Satellite losses and malfunctions would run up to $20 billion losses, Defense Department satellites would be blinded in some ways, and GPS systems would report inaccurately. This would affect precision navigation, oil drilling, search and rescue, and military targeting. 150 million people in north America would suffer a blackout without any precedent. Components of transformers for which there are no replacements would be damaged and have to be manufactured overseas.  The daily cost could be $30 billion in lost salaries, spoiled food, and closures--a larger scale example of the danger of global interconnectedness that the Icelandic volcano Eyjafjallajokull showed us earlier this year.

Rogue wave damages cruise ship

Two days ago (12/07/2010) a cruise ship lost an engine after encountering "monster waves" near the South Shetland Islands north of the Antarctic peninsula. Two videos of the waves are here and here. The ship, The Clelia II, a 5-deck ship, is apparently safe and heading to Ushuia (Argentina), accompanied by an Argentinian naval vessel.  It departed Ushuia for the Antarctic on November 30 and was returning to port yesterday.  The ship is being reported as operated by Polar Cruises based in Bend, Oregon, but Polar Cruises has put out a press release that it neither owns nor operates the ship. It appears that the operator is Travel Dynamics International of New York.. The media is reporting that the ship is carrying 100 passengers and 60 crew members, but several pieces of information in the news conflict with more reliable sources.  According to the International Association of Antarctica Tour Operators, there were 88 passengers and 77 crew.  All of the passengers are from the US. This same ship had an accident Christmas 2009 when a stronger-than-anticipated current pushed it onto rocks at Petermann Island in the Antarctica Peninsula. The starboard propeller struck some rocks, resulting in the shutdown of the starboard engine and loss of electrical power aboard the ship. Damage was significant enough that expeditions were cancelled through mid-January, 2010.

SS Edmund Fitzgerald May, 1975

As can be seen on the video there were heavy seas, and reportedly 55 mph winds northeast of the Shetland Islands. Two ingredients contribute to the creation of rogue waves: strong winds and fast currents. Rogue waves are common in this area of the world because winds have a long interrupted stretch of ocean to blow on the sea surface and build up the waves. For centuries mariners told tales of monster waves up to 100 feet in height.  Mathematical probability theory, however, based on a Rayleigh distribution of wave heights led to conclusions that these waves were unlikely.  A concerted effort to document the waves, including satellite measurements and pressure records from buoys, has now shown that waves exceeding 100 feet are much more common than expected.

Rogue waves also occur on the Great Lakes, and are believed to have cause the sinking of the SS Edmund Fitzgerald in November, 1975. At the time, it was the largest ship (a freighter) on the Great Lakes. The ship sank so quickly that no distress signals were received. When it was located on the bottom later that month, it was found to have broken in two. One theory is that it was hit by the "Three Sisters", a name for the phenomenon that these rogue waves occur in sets (there is a hint of that in the videos above of the recent episode in the Antarctic).  "The Wreck of the Edmund Fitzgerald" was a 1976 hit song by Gordon Lightfoot.

Beautiful, beautiful volcanic picture!

Klyuchevskaya Volcano, December 4, 2010 as observed by the Advanced Land Imager (ALI) aboard Earth Observing-1 (EO-1) satellite. You can link to a high resolution image that covers a larger area here.

This is one of those "worth a thousand word" pictures.  Rarely have I seen a photo in which the atmosphere is so clear around a volcano, the winds are so calm, the lighting is so perfect, and the eruption so striking.  No scale is given for this particular photo, but it is one of a series that have been rising to nearly 8 km (26,000 feet) from Klyuchevskaya.  Perhaps even more striking than the plume is the beautiful collar of pileus clouds surrounding the higher flanks of the mountain. Pileus is the Latin word for "cap". They form when updrafts push up moist air from lower altitudes.  In rising, the air cools to its dew point, causing droplets to form and create the cloud. Pileus clouds often form over cumulus clouds, and over rising plumes themselves as shown in this post about the eruption of Sarychev Peak volcano.

Volcanic plumes have two parts. Near the vent from which they emerge, the ascent of the plume is driven by momentum.  Further away from the vent, the plume rises buoyantly, and at high elevations (not shown here), some plumes form an umbrella. My guess is that this one did not. Plumes transport volcanic ash.  Near the plume, the primary control on ash dispersal is the plume itself--it's momentum and buoyancy characteristics and, to some extent, its interaction with the atmosphere as air is entrained into the eruption column.  Further away from the plume, atmospheric structure and winds control the dispersal of ejecta.  An excellent reference on volcanic plume dynamics is "Physics of Explosive Volcanic Eruptions", Special Publication 145 of the Geological Society of London, edited by R.S.J. Sparks and J.S. Gilbert, 2002.

Cold Lahars Displacing People at Mount Merapi, Indonesia

Dredging in the Code River, Yogyakarta
Photo from here.

Eruptions at Mount Merapi, discussed here, here, and here before in this blog, produced ash and other debris that sits atop the mountain awaiting the monsoon rains. Those rains have arrived; the wet monsoon season in Indonesia lasts from November through March. For weeks muddy torrents have been flowing down from the mountain. On November 30 an apparently big one, reported to be up to 2 meters deep, arrived. According to the Nov. 30 edition of the JakartaGlobe, thousands of residents were forced to evacuate. These muddy flows of volcanic materials are termed "lahars", and they can be either hot or cold depending on the timing of the volcanic activity and the weather.

The lahars flow down the channel of the Code River, which flows through the center of Yogyakarta.  The river has been channelized to control the path of the lahars, a historic danger from Merapi. Sandbags up to 1 meter high help control the flows, but authorities have warned residents that these temporary levees will not contain the large flows that are likely to occur.  Surono, the head of the Volcanology and Geological Disaster Mitigation Agency (PVMBG) has warned that people should stay 300 meters away from the river.  Evacuation has been hindered by damage to roads and bridges, as well as by heavy traffic from people coming in to see the disaster.

An interesting side-bar mentioned in the DredgingToday.com article linked in the figure caption is that the dredging of the Code River has been hampered by the lack of heavy machinery.  However, people living near the river have been helping by manually carting material away.  Apparently it is well known that the volcanic mud is rich in nutrients, and a truck of this material is fetching 50-60 thousand Rp! (50,000 rupiahs convert to about $5.50 US.)