Indeed, I am a few miles too far east. I didn't pick up on the fact that you were looking at Stansbury Island. OK, here's another try. When the pumps were installed in the late 80s to pump water from the lake into the west desert, the new "lake" was used a a concentrating pond for lake water and then it flowed back into the southwest end of the GSL. The water pumped into the west desert was from the north arm, and therefore already saltier and containing the red bacteria and algae. Perhaps the causeway you photographed was to keep this saltier, concentrated water separate from the water returning from the pumps. The red algae Dunaliella Salina and the bacteria species Halobacterium are responsible for the red coloration of the north arm. The green color of the south arm is a result of algae like Dunaliela Virdis. On Tuesday, February 25, 2014 2:49 PM, Larry Holmes <larry@kijoda.com> wrote: On 2/25/2014 7:47 AM, Brent Watson wrote:
The causeway you are looking at was built when I-80 was being constructed. Its purpose was to carry fill from the island for freeway construction. There was actually a belt carrier that brought materials from Antelope Island to the construction site along that causeway. Now, as to the color change, it certainly would need to be another change in mineral content. There isn't much water added to the lake at the south end, and so the salinity must increase. The red color doesn't come from the minerals, but rather from a couple of species of algae and bacteria present in the water that thrive on the high salt content. That's my guess, anyway. BTW, Robert Smithson chose the location for the Spiral Jetty because of the wine red color of the water in the north arm.
Brent, I was told the red color comes from the higher concentration of brine shrimp, esp. after the causeway was built. I do not know about algae, but as I said in an earlier post, I am going to inquire. As Dufus once said, "an inquiring publc has a right to know". 73 _______________________________________________ Utah-Astronomy mailing list http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Send messages to the list to Utah-Astronomy@mailman.xmission.com The Utah-Astronomy mailing list is not affiliated with any astronomy club. To unsubscribe go to: http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Then enter your email address in the space provided and click on "Unsubscribe or edit options".