BEGIN:VCALENDAR
VERSION:2.0
PRODID:icalendar-ruby
CALSCALE:GREGORIAN
X-WR-CALNAME:Colloquium:  Dr. Ittai Gavrieli
X-WR-TIMEZONE:Mountain Time (US & Canada)
BEGIN:VEVENT
DTSTAMP:20260514T105902Z
UID:tag:localist.com\,2008:EventInstance_45277503735928
DTSTART:20240207T223000Z
DTEND:20240207T233000Z
DESCRIPTION:Dr. Ittai Gavrieli\nGeological Survey of Israel\n\nTopic: The D
 ead Sea: Past present and future\n\nAcademic host: Catherine Fontana\n\nAb
 stract: The Dead Sea (DS)\, the lowest place on the continental Earth (cur
 rently at ~ 438 m below sea level)\, is a hyper-saline terminal lake with 
 a unique composition that evolved from evaporation of seawater which trans
 gressed into the Dead Sea Rift Valley in the early Pliocene\, followed by 
 precipitation of evaporites and intensive water rock interactions. Since t
 hen\, the DS basin has been occupied by a series of water bodies of differ
 ent characteristics and areal extents. The sediments deposited from these 
 lakes are excellent archives of the climatic history of the Levant region 
 as well as their limnological evolution. Pore water extracted from sedimen
 ts recovered by the ICDP Dead Sea Deep Drilling Project show that even dur
 ing high stands and positive water balance (mostly glacial periods)\, the 
 lakes were stratified but remained hypersaline. During prolonged periods o
 f negative water balance (inter-glacial) and lake level drops the water co
 lumn underwent overturn and the meromictic regime changed to a monomictic 
 one.  Thick halite intervals recovered by the cores show evidence for seve
 re arid conditions in the eastern Mediterranean during the last three inte
 r-glacials. These halite layers as well as the dominant alternating aragon
 ite and detrital laminae and gypsum and mud layers have been correlated to
  global and local climatic events. \nModern diversion of freshwater from t
 he drainage basin of the DS\, mostly by Israel and Jordan\, as well as eva
 poration of the brine in ponds of the DS chemical industries\, has resulte
 d in water level drop of more than 40 m since the 1960s. Currently water l
 evel continues to drop at an unprecedented rate of over 1 m/yr\, represent
 ing annual water deficient of ~750·106 m3. The massive anthropogenic inte
 rvention in the water balance of the lake has resulted in the onset in 198
 0s of halite precipitation from the brine\, which continues to date. Groun
 dwater level of the coastal aquifer\, and the elevation of the fresh/salin
 e groundwater interface within it\, decline in response to the falling lev
 el of the lake. This has led to wide-spread dissolution of a 10\,000 year 
 old halite layer in the subsurface\, resulting in the development of thous
 ands of sinkholes along the shores of the lake\, in effect making them uns
 afe and the shorelines un-accessible. Incisions of deep canyons in the new
 ly exposed mud flats and alluvial sediments enhance erosion and jeopardize
  and damage the highway that runs along the lake. \nThe desiccation of the
  DS and the associated environmental impacts has led to outcry to “save 
 the Dead Sea”\, which culminated in the proposed Red Sea - Dead Sea proj
 ect to convey reject brine from desalination to the DS\, agreed upon by Is
 rael and Jordan. The aim of this project would be 2-fold: 1) Provide badly
  needed potable water to Jordan 2) Slow down\, stabilize or even raise the
  water level by discharging the reject brine to the DS. However\, our stud
 ies indicate that mixing of the reject brine with the DS brine will have i
 ts own environmental impacts\, including: 1) Dilution and change in compos
 ition of the surface water if discharge volume exceeds 400·106 m3 per yea
 r. 2) Potential “whitening” of the lake due to spontaneous precipitati
 on of gypsum upon mixing. 3) Massive blooming of endemic dunaliella and ar
 chaea in the diluted epilimnion\, enabled by the dilution of the brine and
  supply of phosphate derived from anstiscalants in the reject brine. This 
 blooming will color the lake red and change its appearance. The pro and co
 ns of the environmental impacts as well as the political and social signif
 icance of the said project are at the center of the discussion of the futu
 re of the Dead Sea.
GEO:40.007953;-105.265846
LOCATION:Benson Earth Sciences\, 380
SUMMARY:Colloquium:  Dr. Ittai Gavrieli
URL;VALUE=URI:https://calendar.colorado.edu/event/colloquium_dr_ittai_gavri
 eli
CATEGORIES:Colloquium/Seminar
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