Hatten Down the Batches: Going With the Wind

     The American and Canadian West (including Colorado) has the Chinook winds, France the Mistral (from the Latin for "master wind"), and northern Africa the Sirocco. And, of course, in Paint Your Wagon, "They call the wind Maria(h). . ."

        The Chinook wind is a foehn or föhn which is a type of dry, warm, down-slope wind that occurs in the lee (downwind side) of a mountain range. 

     A record-breaking temperature change of 103 degrees F in 24 hours in January, 1972, was recorded in Loma, Montana, due to the effect of Chinook winds. The temperature rose from -54 degrees to +49 degrees F in this hamlet of 85 people.

       The Chinooks are named after indigenous peoples of the American northwest although local folklore says the wind word (as opposed to windward ;-)) means "ice-eater or snow-eater" for the extreme sublimation of ice and snow in the winds.

       Moving eastward across the Atlantic Ocean to the Mediterranean Sea, these wind patterns (below) all flow into the sea, with the exception of the Levante or Levanter winds which flow westward into the Atlantic Ocean.

     Most winds flow off mountains into the Mediterranean. (I still recall the scent of lavender carried in Provence, France, in the Mistral wind.) In contrast, the Levante(r) winds are mountain-gap winds flowing in the Strait of Gibralter. Here is a levante cloud forming due to the Levante(r) winds:

       Yes, it's definitely time to hatten down the batches in our strong winds. Have you experienced the Chinook, the Mistral, the Sirocco, the Maria(h) or Levante(r) winds? Any cool cloud images to share?

Whoosh,

Steph

Ethiopian "Buna" or Coffee 

Ethiopian Welo Opals, Oh Pals!

     Ethiopian opals from the Welo District include this spectacular specimen discovered in October 2013. 

     The Ethiopian Welo opal mines were first discovered in 2008 in the district north of the capital of Addis Ababa (although opal was said to have been discovered in the 1930's elsewhere in Ethiopia and minimal mining began in the 1990's):

       The USGS estimates 2012 production of Ethiopian Welo opal to be 14,000 kilograms or 31,000 pounds. This estimation would change Australia's purported 95-97 percent of the world's opal production. There is not much information currently available about the Ethiopian Welo opal mines. Perhaps my daughter, Zoe, can make a field trip to the north to discover more about their deposition (or I could visit her and the opal mines!). I am quite curious about the similarities between the depositional environments in Australia and Ethiopia. 

    Opal is a hydrated amorphous form of silica with a water content ranging from 3 to 21% by weight. Because of its amorphous character, it is classed as a mineraloid, unlike the other crystalline forms of silica, which are classed as minerals.

     Australian opal is generally of a higher water content than the Ethiopian Welo opal. It is also generally found in deeper environments. Opals which get too dry are said to "craze." Often gemologists store opals in water to keep them hydrated. I take mine swimming.

      This four minute long video of Welo opals is worth a look, oh pals!

       I like the fire and the setting of this Ethiopian opal.

     Speaking of Ethiopia, here's the Peace Corps group arrival at the airport in Addis Ababa. Where's Waldo (er, Zoe?!) What an enthusiastic bunch (especially just after a 13-hour plane ride)!

                                             ^

                  

O pals, let me know your silica thoughts,
Steph