Talk:San Francisco Bay

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hello there. what is the depth profile of the sf bay? tks.

1 About the cryptid footnote
2 Re: Depth profile
3 קטגוריה
4 Bay

[edit] About the cryptid footnote

Who wants to give the cryptid rumoured to live in the bay a name?I can't think of any

[edit] Re: Depth profile

SF Bay's profile changed dramatically in the late nineteenth century and again with the initiation of dredging by the US Army Corps of Engineers in the twentieth century. Before about 1860 most bay shores (exception: rocky shores such as those in Carquinez Strait, along Marin shoreline, Point Richmond, Golden Gate area) contained extensive wetlands that graded nearly invisibly from freshwater wetlands to salt marsh and then tidal mudflat. A deep channel ran through the center of the bay, following the ancient drowned river valley.

In the 1860s and continuing into the early twentieth century, miners dumped staggering quantities of mud and gravel from hydraulic mining operations into the upper Sacramento and San Joaquin Rivers . GK Gilbert's estimates of debris total more than eight times the amount of rock and dirt moved during construction of the Panama Canal. This material flowed down the rivers, progressively eroding into finer and finer sediment, until it reached the bay system. Here some of it settled, eventually filling in Suisun Bay, San Pablo Bay, and San Francisco Bay, in decreasing order of severity.

By the end of the nineteenth century, these "slickens" had filled in much of the shallow bay flats, raising the entire bay profile. New marshes were created in some areas.

In the last years of the nineteenth and first decades of the twentieth century, at the behest of local political officials and following Congressional orders, the US Army Corps began dredging the Sacramento and San Joaquin Rivers and the deep channels of SF Bay. This work has continued without interruption ever since, an enormous federal subsidy of SF Bay shipping. Some of the dredge spoils were initially dumped in the bay shallows (including helping to create "Treasure Island" on the former shoals to the north of Yerba Buena Island) and used to raise an island in the Sacramento-San Joaquin Delta. The net effect of dredging has been to maintain a narrow deep channel--deeper perhaps than the original bay channel--through a much shallower bay. At the same time, most of the marsh areas have been filled or blocked off from the bay by dikes.

So, the bay profile has gone from a kind of saucer shape (extensive tidal marshes, much shallow bay, a deeper area) to an even flatter profile with a very deep nick in the center (little marsh, extensive very shallow mudflats, a very deep sheer channel in the center).

Sources: Goals Project, Baylands Ecosystem Habitat Goals (US EPA, 1999, 2000); San Francisco Estuary Institute, EcoAtlas (online resource); Grove Karl Gilbert, Hydraulic Mining Debris in the Sierra Nevada Prof Paper No. 105 (USGS, 1917)

I'd love to see this incorporated in the article. Article is long enough that it needs subheads already; this could be another one, extending what I originally added about dredging & filling. I spent about half an hour yesterday on the web trying to find a public domain, clearly readable map showing how much has been filled over time (and when), but didn't succeed. Found very small, hard to read, outdated, probably (c) one only. Elf | Talk 22:45, 23 Mar 2004 (UTC)

I would like this sentence to be rewritten. It's not very clear in the current format.

The San Francisco Bay is a shallow, productive estuary in which water draining approximately forty percent of California, flowing in the Sacramento and San Joaquin rivers from the Sierra Nevada mountains, enters the Pacific Ocean.

Thanks. --Sennaista 00:24, 17 December 2005 (UTC)

[edit] קטגוריה

אין לערך הזה קטגוריה בכלל! איך זה יכול להיות? לא אמורה להיות קטגוריה לכל הערכים בויקיפדיה? בויקיפדיה העברית זה לא היה קורה! IRA 13:40, 5 July 2006 (UTC)