Happiness in hexagon form

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Anyone visiting Israel during the holiday seasons from September to October and March to April discovers that the entire country is on vacation and on the road. During the recent Passover holiday, the radio news kept broadcasting figures for the number of visitors to the National Park system. On one particular day, the numbers hit a record of 80,000. With the temperatures well over 90 degrees, water features were particularly popular. 

We were vacationing in the north, which is within easy driving distance of the Golan Heights — that part of Israel to the north and east of the Sea of Galilee (Yam Kinneret). Our agenda included the Hexagon Pool otherwise known as Brachat HaMeshushim — meshushim is the Hebrew word for hexagon — which is part of the Yehudiya Nature Reserve.

The gateway to the main attraction was a large flat area filled with plantings, parked cars and families barbecuing. Just as the summer barbecue is de riguer on many public holidays in the States, the barbecue — known here as a mangal — is a requisite part of entering Nature for the day.

I expected that a short walk would bring us to the formation of basalt rock from which the park gets its name. There was, indeed, a sign pointing off to the pool and we gamely walked along. Forty-five minutes later, after descending hundreds of feet into the ravine created by the Meshushim Stream, we reached our destination.

The water was cold — about 64 degrees — but plenty of children and adults waded in to swim. We simply sat on some fallen logs and enjoyed the rest, the view and the excitement of the children splashing in the water.

Despite the interesting flora and fauna, the main attraction is the sheet-like drape of hexagonal-shaped basalt columns at the foot of the trail. Basalt is an dark, igneous rock that is generally fine-grained, rich in iron and manganese and low in silica. The hexagonal fracturing is the result of the cooling process after large masses of lava flow out of the Earth. Lava begins cooling immediately as it is exposed to the relatively air and its mass begins to shrink. 

With massive flows, it can fracture in the horizontal plane side-to-side as it begins to cool. It can, however, accommodate shrinkage in the vertical plane and this causes the visible columnar fracturing. Although fracturing yields mostly hexagons, it seems that columns with slightly more or fewer columns are common, too. The diameter of the columns depends on the rate of cooling, with rapid cooling giving rise to small columns — those less than 1 centimeter — while slow cooling over years yields columns of larger diameter.

While these columnar formations cannot be seen everywhere, they are not that rare. The best known formations are Devil’s Postpile National Monument in California, Devil’s Tower National Monument in Wyoming, Giant’s Causeway in Ireland, and Svartifoss in Iceland, where the formations look eerily similar to those at the Meshushim. 

Luckily for those of us living in Riverdale, the Palisades, which are breathtaking in the winter, are formed from such jointing. Examples can also be seen in at Hemlock Falls in Milburn, New Jersey, which involves a little hiking. Another spectacular example on the East Coast can be found in the Shenandoah National Park, Virginia.

I look forward to you, the readers, sharing your interests in the natural world with me since they may suggest future columns (forgive the pun). Let me know in the comments section.

Green scene, Sura Jeselsohn

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