Éclairez ma lanterne! Enlighten me!

Lower Mystic Lake is located a few miles North West of Boston. It is connected upstream to upper Mystic Lake and downstream to Mystic River which empties into the Boston harbor.

The most distinctive feature of this lake is that it is a Meromictic lake, which is a rare type of lake (one counts around 200 in the word).
Unlike a Holomictic lake (the most common type) a Meromictic lake is a deep body of water lacking complete circulation of its upper and deeper layers of water. Due to this absence of mixing waters, the deeper layer receives little oxygen (less than 1 mg/l) from the atmosphere and sediments at the bottom remain undisturbed. Thus, such lakes preserve records of the geologic past of the lake exceptionally well.

Studies were performed by experts who found occasional layers of coarse sediment that had washed into the lake during flooding events and concluded that hurricanes have struck the Boston area. This record extends back to 1011 A.D. In terms of hurricanes activity the number was higher between the 12th and the 16th century.

Lower Mystic Lake est situé à quelques kilomètres au Nord Ouest de Boston. Il est connecté en amont au Upper Mystic lake et en aval à la rivière Mystique qui se jette dans le port de Boston.

La particularité de ce lac vient du fait que c'est un lac méromictique: un type de lac assez rare dans le monde (on en dénombre environ 200 ).
A la différence d’un lac holomictique (le type le plus commun), un lac méromictique est un lac très profond qui se caractérise par l’absence de circulation complète entre les eaux de surface et les eaux profondes. Du fait de cette absence de mélange des eaux, les couches profondes reçoivent très peu d’oxygène (moins de 1 mg/l) de l’atmosphère et les sédiments au fond restent stables. En conséquence, de tels lacs renferment des informations géologiques remarquables sur l’histoire du lac.

Des recherches ont été menées par des experts qui ont trouvé d'épaisses couches de sédiments déposés au fond du lac pendant des périodes d'inondations et en ont conclu que des ouragans avaient frappé la région de Boston. Les résultats obtenus ont permis de remonter jusqu'à l'an 1011 après Jésus-Christ. En termes d'activité cyclonique, le nombre d'ouragans était plus important entre les 12ème et 16ème siècles .

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French Expression in context / Expression française en contexte

1. “ Eclairer la lanterne de quelqu'un " (lit: to light somebody's lantern!): To enlighten somebody This expression is an allusion to Florian's Fable: "The Monkey showing the Magic Lantern"(1792) (French version here) which tells the story of a man who owns an outwit monkey called Jacqueau, and a magic lantern (a lantern projection). One day, the man leaves home to go to the cabaret. To impress all the animals of the village, the monkey decides to perform a show in front of them to explain how the world was created using the lantern as the sun. However one important detail was missing! He forgot to light up the magic lantern and as a result, the audience did not understand anything. After this fable was published the expression "oublier d'éclairer sa lanterne " (to forget to light one's lantern) was created and meant "missing the main point". 2. "Prendre des vessies pour des lanternes " : (lit: to take bladders for lanterns.) To think the moon is made of green cheese! Dating back to the late Middle-Ages, this expression is a play on word. It derives from the old form "vendre des vessies pour des lanternes" (to sell bladders for lanterns), where the words "lanternes" (lanterns) and "vessies" (bladders) had similar figurative sense. In old French, the word "lanternes", in the plural form, referred to “des balivernes” (twaddles) and the word "vessies" meant “des bagatelles” (trifles), or something empty, hollow, like the bladder. Eventually, the "lanternier" (the lantern merchant) was “un diseur de balivernes et de bagatelles” (a teller of trifles and twaddles"). However, in Medieval times, pigs or beef bladders (vessies de porc ou de boeuf) were commonly used as a recipient ( a goatskin flask), a ball or a lantern. The bladders were hung from the ceiling to dry, and then inflated before being used. A candle was placed inside beforehand. Et voilà! That does the trick!"! A bientôt!