NOAA and partners document surge in Great Lakes water levels

 

Article posted by Canada Sentinel Photo by Steven J. Myers

Ann Arbor, MI--Scientists at the Army Corps of Engineers, Environment Canada, and NOAA recently documented a record-setting surge in water levels on Lakes Superior and Michigan-Huron that began in January 2013, and has continued through November 2014. The United States and Canadian federal agencies expect water levels to stay near or above average on all of the Great Lakes over the next six months.
At no other point in recorded history have water levels risen as much on Lake Superior and Michigan-Huron over the same two-year period. Since September 2014, all of the Great Lakes have been above their seasonal averages for the first time since the late 1990s.
“The recent surge in water levels brings to an end a 15-year period of persistent below-average water levels on Lakes Superior and Michigan-Huron,” said Drew Gronewold, a research hydrologist with NOAA’s Great Lakes Environmental Research Laboratory. “However, it is uncertain if, years from now, water levels will continue to rise, or if they will fall again to below-average levels.” 

Docks were high and dry

Low water levels were the story on Lake Michigan and across the Great Lakes in early 2013, as pictured here in Grand Traverse Bay, Michigan. (Michigan Sea Grant)

Part of the uncertainty in long-term future water levels projections comes from the challenge of predicting not only the major drivers of the Great Lakes water budget (which are over-lake precipitation, runoff and over-lake evaporation) but also large-scale climate forces, such as last winter's Arctic polar vortex anomaly, which influence those drivers. The surprisingly swift rebound in water levels broke records across the region. The net rise in water levels on Lake Superior from January 2013 through November 2014 was roughly 2.3 feet (about 0.7 meters), the highest net increase ever recorded for that 23-month period. Similarly, on Lake Michigan-Huron, the net rise in water levels from the record-low in January 2013 through November 2014 was 3.2 feet (about 1 meter), an increase that tied the previous record set in 1950-1951 for the same 23-month period.
The current surge in water levels has largely provided relief to communities, businesses and industries that depend on the Great Lakes, including commercial shipping, hydropower, recreational boating and tourism. However, high water levels can have negative effects as well, including coastal erosion, flooding, and property damage along the shoreline. The severe storm in October 2014 that lashed the shores of southern Lake Michigan is just one example.
Research from NOAA, the Army Corps, Environment Canada, and regional academic institutions indicates that increases in seasonal precipitation are the major cause of the recent water level surge. Measurements from a growing network of off-shore evaporation monitoring stations indicate that evaporation rates in the recent two-year period have not been particularly low despite recent cold winter temperatures and record high ice cover. So while high evaporation rates were a major factor in keeping water levels low between 1998 and 2013, an increase in precipitation appears to be the major driver of the recent water level surge. 
Data suggests that precipitation in the Lake Superior and Lake Michigan-Huron basins was about 10 percent above long-term averages in both 2013 and 2014, while precipitation in 2012 (a year of drought that preceded the record low water levels on Michigan-Huron) was roughly 10 percent below the long-term average. 
NOAA and Army Corps scientists are also studying how a changing climate may contribute to water level changes. To improve the understanding of the relationship between climate change and Great Lakes water levels, GLERL researchers and their academic partners analyze relationships between evaporation from the lakes, seasonal ice cover, and long-term heat storage in the lakes.
This research would not be possible without the continuous operational water level and meteorological monitoring networks provided by U.S. and Canadian federal agencies, as well as the research-oriented monitoring stations of partner academic institutions. The water level stations maintained by the NOAA/National Ocean Service Center for Operational Oceanographic Products and Services (CO-OPS), for example, provide one of the longest high quality hydrometeorological data sets in North America, with data beginning in 1860. Research and monitoring of Great Lakes water levels and regional meteorological conditions is an important part of NOAA’s mission to understand and predict changes in climate, weather, oceans, and coasts.

Revealing the Secrets of “San Francisco’s Titanic”

Article By Katie Teshima

The morning of February 22, 1901, was much like any other on San Francisco Bay.

A thick blanket of fog spread across the water as the steamer City of Rio de Janeiro approached the Golden Gate, laden with passengers and freight from Hong Kong, Yokohama and Honolulu. Returning to San Francisco after more than two months at sea, the City of Rio’s cabins brimmed with the hopes and dreams of Chinese and Japanese immigrants seeking a new life in the United States. Up on deck, Captain William Ward and Pilot Frederick Jordan steered what they thought to be a safe course into the narrow mouth of the Bay, but could make out no landmarks through the damp gray void.

Present day photo at the entrance of the Golden Gate looking westward with Fort Point at the far left where the SS City of Rio de Janeiro struck the rocks and foundered on February 22, 1901. (Photo: Robert V. Schwemmer NOAA)

Shortly after 5 a.m., with visibility still at zero, disaster struck. The 345-foot steamer had veered too far south on its approach and suddenly ground to a halt on the jagged rocks of Fort Point, tearing a massive gash in its iron hull. A strong ebb tide soon pushed it back off of the rocks and allowed the frigid winter waters of the Pacific to rush into the engine room and cargo holds.Passengers and crew fought their way to the deck, but confusion reigned on the rapidly sinking ship. Within a matter of minutes, the City of Rio succumbed to its wounds and slipped beneath the waves, taking with it 128 of the 210 lives on board.Now, with the help of several private partners and cutting-edge technology, NOAA’s Office of National Marine Sanctuaries has brought back the first-ever 3-D images of this long-lost shipwreck, which historians have called the “Titanic of the Golden Gate.”

Multibeam sonar image at San Francisco's Golden Gate highlighting the shipwrecks City of Rio de Janeiro, City of Chester and Fernstream. (Credit: Gary Fabian for NOAA)

This November, a joint archaeological expedition led by the Office of National Marine Sanctuaries Maritime Heritage Program set out to document the wreck as part of a two-year study of shipwrecks in Gulf of the Farallones National Marine Sanctuary and the surrounding area. Bay Marine Services LLC provided a vessel and crew for the mission, while Hibbard Inshore LLC and Coda Octopus equipped the research team with a high-powered remotely operated vehicle (ROV) and 3-D sonar array to aid in the search.West Coast Regional Maritime Heritage Coordinator Robert Schwemmer worked in cooperation with Maritime Heritage Program Director James Delgado and sonar expert Gary Fabian to pinpoint the location of the City of Rio, which lies 287 feet below the surface just outside the Golden Gate, not far from where it ran aground in 1901.

CodaOctopus 3-D Echoscope sonar images of the SS City of Rio De Janeiro. (Credit: Coda Octopus/NOAA)

The 3-D model generated by the Coda Octopus “Echoscope” sonar also gave researchers an entirely new perspective on the condition of the wreck site. What they found was a crumpled, scarcely recognizable iron hulk encased in more than a century worth of mud and sediment, lending support to the narrative that the ship sank quickly before many of its passengers could escape.The expedition team also remapped the S.S. City of Chester,a second nearby wreck that was rediscovered in May 2013 by NOAA’s Office of the Coast Survey. In stark contrast to the City of Rio, the Echoscope revealed in great detail the surprising level of preservation of the City of Chester’s frame and propulsion machinery, telling a very different story about the circumstances of its sinking.

Survivors from SS City of Rio de Janeiro after the sinking at Baker's Beach. (Credit: San Francisco Maritime National Historical Park safr_21374_a11-14617_p)

Through advanced technology and innovative partnerships, NOAA is breaking new ground in our quest to explore and understand our nation’s maritime heritage. Shipwrecks once believed to be lost forever are now within our reach, and those we have studied in detail continue to give up new secrets with each subsequent expedition. This discovery is a reminder of NOAA’s commitment to protecting the profound ties that the nation has to our history lying beneath the ocean’s surface.