Friday, August 22, 2014

New Data about the melting of our planet's ice sheets

This week researchers from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), have for the first time extensively mapped Greenland’s and Antarctica’s ice sheets with the help of the European Space Agency's satellite.  This dedicated group has been able to prove that the ice crusts of both regions have declined at an unprecedented rate.  The comprehensiveness of this research shows beyond a shadow of a doubt that the impact of global climate change is a reality.

Below are a few photos taken by the research team of the ice sheets.  




The team showed the decline in the ice sheets by measuring the elevation of the ice.  The researchers derived the elevation change maps using over 200 million data points for Antarctica and around 14.3 million data points for Greenland. The results reveal that Greenland alone is reducing in volume by about 375 cubic kilometres per year. When the research team compared the current data with data from the year 2009, they discovered that the volume loss in Greenland has doubled over the last five years. The loss of the West Antarctic Ice Sheet has in the same time span increased by a factor of three. Combined the two ice sheets are thinning at a rate of 500 cubic kilometres per year. That is the highest speed observed since altimetry satellite records began about 20 years ago,

The following charts were created from this extensive data. 

First Antarctica:


Greenland:


The two images below show where the loss in ice has occurred.



Other data and conclusions published by this research team include the impact of increased carbon dioxide levels on the acidity of the oceans.  Around half of the carbon dioxide volume discharged into the atmosphere through exhaust pipes and chimney stacks over the past two hundred years has been absorbed by the oceans - but not without consequence. The carbon dioxide dissolves in the water, creating carbonic acid. This reduces the pH value of the seawater and makes the oceans more acidic.  An example of this impact is shown in the ocean's corals.  Corals are amongst those sea dwellers to be the most greatly affected by rising temperatures and the falling pH value of the oceans. Warmer and more acidic seawater causes them to lose their colourful appearance and reduces the energy available to develop their exoskeleton.


Scientists long assumed that ocean acidification had little impact on more highly developed organisms such as fish. However, more recent research results prove the opposite: fish react sensitively to acidic water primarily at the beginning of their lives – the very time their development is in full swing.
 

To summarize the impact of the acidification of the oceans, 63 scientists from 47 institutions and 12 countries participated in writing of facts included on the webpage:

http://www.awi.de/fileadmin/user_upload/News/Im_Fokus/Ozeanversauerung/OA20Facts11_6bfinal.pdf

CITES:
All data and images are from: http://www.awi.de/en/news/press_releases/detail/item/record_decline_of_ice_sheets_for_the_first_time_scientists_map_elevation_changes_of_greenlandic_and/?cHash=64ac737e3447ae4ca984e3bbd97480fe
Angelika Humbert, Alfred-Wegener-Institut
Robert Ricker, Alfred-Wegener-Institut
Helm et al., The Cryosphere, 2014
G. Schmidt, Alfred Wegener Institute

Tuesday, August 19, 2014

New Agate Lamp

Last night and this morning I worked to finish a new agate lamp that I've been working on for a few days.  So for today's posting, I am including a photo.  It is now available for sale.  If you are interested, please send me an email to karen@agatelady.com


Monday, August 18, 2014

More Agate Close Ups

I originally planned on going on a hike last night after closing the museum, but I wasn't feeling well so I decided to just head home.  I don't know if it is a summer cold or allergies, but I don't do well when my head is all stuffed up.  So for today's blog posting, I pulled out my USB microscope again and took some pictures of a few of Neil Snepp's agates that were donated to the museum by his family.

Lake Superior agate....


Lake Superior agate....


Lake Superior agate....


Crowley Ridge agate (Arkansas)....



Lake Superior agate....


Lake Superior agate....


Saturday, August 16, 2014

Awesome Lake Superior Agate

In 16 years of operating the Gitche Gumee Museum, I have never before tried to buy a single agate brought into the museum.  However, a month ago Mark Bowen from Sault Ste. Marie came in to visit.  He read my agate book last fall and jumped into the agate world with both feet.  When winter engulfed the U.P., he went agate hunting on EBay and purchased this very rough and crusty Lake Superior agate.


Even though the outer surface was coated in limonite and other minerals, he saw interesting detail.






So Mark ground away the outer husk to reveal in interesting and very intricate tube agate.







My guess about this agate's formation is that the vesicle pocket may have been intermittently dry allowing dripping into the pocket, resulting in the formation of stalactites as well as other rod-like minerals, all of which were later replaced with chalcedony.  I love this agate.  Mark:  thanks for selling it to me.  And, yes, you have visitation rights.

Friday, August 15, 2014

New Cassini Images of Saturn

This morning I decided to check in with the Cassini Solstice Mission to see what new images of Saturn are available at the webpage http://saturn.jpl.nasa.gov/.



Seen within the vast expanse of Saturn's rings, Prometheus appears as little more than a dot. But that little moon still manages to shape the F ring, confining it to its narrow domain.

Prometheus (53 miles, or 86 kilometers across) and its fellow moon Pandora (50 miles, or 81 kilometers across) orbit beside the F ring and keep the ring from spreading outward through a process dubbed "shepherding." 




The first image above shows the geyser on one of Saturn's moons, Enceladus.  The second image is an artist's rendering showing a cross-section of the ice shell immediately beneath one of Enceladus' geyser-active fractures, illustrating the physical and thermal structure and the processes ongoing below and at the surface. Narrow cracks extend upward from the sub-surface sea all the way to the surface, through both ductile and brittle layers of the ice shell.  Liquid water under pressure fills the cracks, keeping them open even through the ductile layer and providing a conduit for vapor and sea water to reach the near-surface. Other processes, such as volatile exsolution of gases, can drive vapor and water droplets all the way to the surface, forming geysers and condensing close to the surface, depositing latent heat. This heat is observed by Cassini's long-wavelength infrared instruments as the small-scale hot spots (dozens of feet, or tens of meters, in size) surrounding each geyser. The subsurface regions immediately surrounding the cracks bearing water and vapor are expected to be warm. Regional heating from tidal flexing is also expected to be present, but is so far undetected.   The third graphic shows a 3-D model of 98 geysers whose source locations and tilts were found in a Cassini imaging survey of Enceladus' south polar terrain by the method of triangulation. While some jets are strongly tilted, it is clear the jets on average lie in four distinct "planes" that are normal to the surface at their source location.



The image above shows a colorized mosaic representing the most complete view yet of Titan's northern land of lakes and seas. Saturn's moon Titan is the only world in our solar system other than Earth that has stable liquid on its surface. The liquid in Titan's lakes and seas is mostly methane and ethane.



in the image above the Cassini spacecraft captures three magnificent sights at once: Saturn's north polar vortex and hexagon along with its expansive rings. The hexagon, which is wider than two Earths, owes its appearance to the jet stream that forms its perimeter. The jet stream forms a six-lobed, stationary wave which wraps around the north polar regions at a latitude of roughly 77 degrees North. This view looks toward the sunlit side of the rings from about 37 degrees above the ringplane. The view was obtained at a distance of approximately 1.4 million miles (2.2 million kilometers) from Saturn.


CITES:
NASA/JPL-Caltech/Space Science Institute

Thursday, August 14, 2014

Earth Observatory Images from NASA

For today's blog posting I decided to check in with NASA's website http://earthobservatory.nasa.gov/.  As many of you know, I like to check in with this website to see what new images of earth have been posted.



The two images above show how the glacial ice in the Brabazon Range in Alaska has changed over the last 25 years.  On the time scale of a glacier, the amount of ice is shrinking quite rapidly. Novatak and East Novatak glaciers, located just a few kilometers apart near the outlet of the Alsek River, are two of many retreating glaciers in southeastern Alaska. Over the last 25-years, the ends of Novatak and East Novatak have each retreated by more than a kilometer.

Snowfall in higher-elevation accumulation zones feed both glaciers. Over time, fresh snow compresses into ice that slides through alpine valleys and into a low-lying plain north of the Alsek. Meltwater collects near the ends of the glaciers, forming a sizable proglacial lake. This lake, filled with opaque, light-blue water, is drained by small streams that connect to the Alsek River a few kilometers to the south. The water’s distinctive color is caused by the presence of rock flour, a fine-grained silt formed by glacial ice grinding against rock.
This pair of satellite images illustrates how much both glaciers changed over a 26-year period and how that change affected the lake between them.

Notice how much the terminus of each glacier has shifted. Novatak retreated by about 1 kilometer (0.6 miles); East Novatak moved back by about two. Also note how part of the lake changed color. As the terminus of East Novatak retreated up into a mountain valley, it cut off a small tributary that supplied meltwater to the western lobe of the lake. With the supply of rock flour cut off, that part of the lake became dark blue. Meanwhile, the other side expanded and changed shape as East Novatak retreated.

CITE: NASA Earth Observatory image by Jesse Allen, using Landsat data from the U.S. Geological Survey. Original caption by Adam Voilan.





The images above show the Antarctic ozone hole on September 16 (the International Day for the Preservation of the Ozone Layer) in the years 1979, 1987, 2006, and 2011. 

Stratospheric ozone is typically measured in Dobson Units (DU), which is the number of molecules required to create a layer of pure ozone 0.01 millimeters thick at a temperature of 0 degrees Celsius and an air pressure of 1 atmosphere (the pressure at the surface of the Earth). The average amount of ozone in Earth’s atmosphere is 300 Dobson Units, equivalent to a layer 3 millimeters (0.12 inches) thick—the height of 2 pennies stacked together.

In 1979—when scientists were just coming to understand that atmospheric ozone could be depleted—the area of ozone depletion over Antarctica grew to 1.1 million square kilometers, with a minimum ozone concentration of 194 Dobson Units. In 1987, as the Montreal Protocol was being signed, the area of the hole reached 22.4 million square kilometers and ozone concentrations dropped to 109 DU. By 2006, the worst year for ozone depletion to date, the numbers were 29.6 million square kilometers and just 84 DU. By 2011, the most recent year with a complete data set, the hole stretched 26 million square kilometers and dropped to 95 DU.

According to NASA, “The Antarctic hole is stabilizing and may be slowly recovering. Our focus now is to make sure that it is healing as expected.” The amount of ozone-depleting substances (ODS) in the atmosphere has stopped rising in recent years, and may actually be decreasing. The yearly ozone hole should continue for a while, though, as CFCs and other ODSs can last for decades in the air. Scientists found in a 2009 study that without the Montreal Protocol, global ozone depletion (not just Antarctic) would be at least 10 times worse than current levels by 2050.

CITE: NASA animation by Robert Simmon, using imagery from the Ozone Hole Watch. Original caption by Mike Carlowicz.




In early August 2014, not one but two hurricanes were headed for the Hawaiian Islands. Storms arriving from the east are a relative rarity, and landfalling storms are also pretty infrequent.  The first image shows a nearly cloud-free eye in the center of a symmetrical storm; there is solid ring of clouds around the center rather than intermittent, spiral bands. Iselle was at its peak intensity at the time.  On August 5, the second natural-color image was captured of both Iselle and Hurricane Julio en route to Hawaii.  Note that Iselle’s eyewall had grown less distinct; the storm had decreased to category 2 intensity. The bright shading toward the center-left of the image is sunglint, the reflection of sunlight off the water and directly back at the satellite sensor.

CITE: NASA image by Jeff Schmaltz, LANCE/EOSDIS Rapid Response. Original caption by Mike Carlowicz.

Wednesday, August 13, 2014

Lake Superior Agate Close Ups

When I sorted the 200 pounds of raw Lake Superior agates that I recently purchased, I separated a few that I thought would be candidates for getting some USB microscope camera photos.  Last night I pulled out the camera and played with the agates.

Rough carnelian husk....



Tubes....


Limonite coated detail...


Chromatography stained agate bands....


Chalcedony bands intertwined with macro quartz bands, along with some peeler action....




This agate husk has a bit of everything....


Iron oxide inclusions....


Tuesday, August 12, 2014

Beach Walk and Super Moon

Last night I went on a beach walk with friends, Lois and Jamey.  It was an absolute gorgeous evening -- and there were no bugs!

A few feet more of sand is evident on my favorite beach, located east of Grand Marais.  Once we went down the bluff, we still have to walk east since there is no beach to the west.


Once we walked a quarter mile east, there was even some rock.


Enough rock, that Lois found a nice shadow agate.

 

Believe it or not, the fall colors are already starting -- probably due to the drought.


Jamey up on the bluff being Jamey....



At the bottom of the bluff notice the sedimentary layers that have bands of black sand.



The photos below could be macro shots of sandstone cliffs from out west.

 
 

White pine tree...


Driftwood sculpture...


Looking west toward town....


This mother killdeer bird was trying to keep us away from here nest.


 Heading back....



The sunset, still setting into the fog that is still out over the lake.








Sunday night entertained us with a supermoon. A supermoon is the coincidence of a full moon or a new moon with the closest approach the Moon makes to the Earth on its elliptical orbit, resulting in the largest apparent size of the lunar disk as seen from Earth. The technical name is the perigee-syzygy of the Earth-Moon-Sun system. The term "supermoon" is not astronomical, but originated in modern astrology. The association of the Moon with both oceanic and crustal tides has led to claims that the supermoon phenomenon may be associated with increased risk of events such as earthquakes and volcanic eruptions, but the evidence of such a link is widely held to be unconvincing. 


A supermoon is shown in the above photo in the right image, to show that it is larger than the normal moon's diameter.  The Moon's distance varies each month between approximately 357,000 kilometers (222,000 mi) and 406,000 km (252,000 mi) due to its elliptical orbit around the Earth (distances given are center-to-center).According to NASA, a full moon at perigee is up to 14% larger and 30% brighter than one at its farthest point, or apogee.

I took the pictures below from the sand dunes over Sable Lake.



 
 


 

Cites:
Marcoaliaslama, http://en.wikipedia.org/wiki/Supermoon#mediaviewer/File:Supermoon_comparison.jpg
http://en.wikipedia.org/wiki/Supermoon