Larger than Emerald Lake, Lake Helen has the look of a true alpine lake. About 110 feet deep and frozen over the seven to eight months each year, its summer temperature may only reach 39 degrees F. at the bottom. ทะเลสาบเฮเลน เป็นทะเลสาบอัลไพน์ที่อยู่ในหุบเขาที่โอบล้อมรอบลักษณะเหมือนอัฒจรรย์ หรือที่เรียกว่า Cirque Lake มีความลึกถึงกว่า 33 เมตรจึงทำให้น้ำในทะเลสาบดูดเก็บสีแดงและสีเขียวไว้ แล้วสะท้อนสีฟ้ากลับออกมา ลักษณะเดียวกับ เลคทาโฮ่ (Lake Tahoe) และ เครเตอร์เลค (Crater Lake) น้ำในทะเลสาบเย็นมากอยู่ที่ประมาณ 4 องศาซี เพราะน้ำเป็นน้ำแข็งอยู่ถึงประมาณ 8 เดือนในหนึ่งปี ทะเลสาบเฮเลน ตั้งชื่อตาม เฮเลน เพียร์สัน โบ้ท ซึ่งเป็นผู้หญิงที่ไม่ใช่คนอเมริกันอินเดียนคนแรกที่ปีนไปถึงยอดลาสัน (Lassen Peak) ในปี 1964 Lake Helen is a cirque* lake that is somewhere between 25,000 and 120,000 years old. Compared to Emerald Lake (Stop 5) which is shallow and therefore warmer, permitting algae to grow and color the lake emerald green, Lake Helen is much deeper and colder. In normal summers it remains snowbound along the edges until well into late July or August. The lake gets its sky blue tint from the deep waters that absorb all the red and green colors, while refracting the blue colors back into the air. This is typical of deep alpine lakes, such as Lake Tahoe and Crater Lake. Who was Helen? Lake Helen (once named Sapphire Lake) is named for Helen Tanner Brodt, the first non-American Indian woman known to have climbed Lassen Peak. She reached the summit on August 28, 1964, with her husband and Major Pearson B. Reading. On their route, they passed by a small beautiful lake that Pearson immediately named Lake Helen. Brodt was also a painter of western scenes and pioneer portraits, and today her work is in the Bancroft Library of the University of California, Berkley. Tree Line As elevation is gained, trees diminish in size and number as environment conditions become increasingly harsh. As some point, 'tree line' or 'timberline' is reached, that elevation above which conditions are too harsh for trees to grow. This level generally rises from north to south. Timberline occurs at around 1500 feet in Southeast Alaska, increasing to 5,500 feet in British Columbia, 6,800 feet on Mount Rainier and 9,000 to 9,500 feet in Northern California. It's even higher in Yosemite and Kings Canyon National Parks. *A cirque (from a French word for "arena"), corrie (from Scottish Gaelic coire meaning a pot or cauldron) or cwm (Welsh for "valley") is an amphitheatre-like valley head, formed at the head of a valley glacier by erosion. The concave amphitheatre shape is open on the downhill side corresponding to the flatter area of the stage, while the cupped seating section is generally steep cliff-like slopes down which ice and glaciated debris combine and converge from the three or more higher sides. The floor of the cirque ends up bowl shaped as it is the complex convergence zone of combining ice flows from multiple directions and their accompanying rock burdens, hence experiences somewhat greater erosion forces, and is most often scooped out somewhat below the level of the cirque's low-side outlet (stage) and its down slope (backstage) valley. If the cirque is subject to seasonal melting, the floor of the cirque most often forms a tarn (small lake) behind the moraine and glacial till damming the outlet.


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Lassen - July 9, 2012 - Stop 7: Lake Helen
โพสต์เมื่อ วันศุกร์ ที่ 13 กรกฏาคม 2555
เวลา 12:50
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