Views of the Sea Floor Near the Entrance to San Francisco Bay | Hacker News Reader

Views of the Sea Floor Near the Entrance to San Francisco Bay

pubs.usgs.gov

120 pointsmtviewdave24 comments

If this is interesting to you, you should definitely check out the Bay Model (https://en.wikipedia.org/wiki/U.S._Army_Corps_of_Engineers_B...). Its a scale model of the SF Bay and the Delta in Sausalito that was built by the Army Corps of Engineers. Its admission free!

is that real water in there?

Yes - Mythbusters used it for the Alcatraz escape episode to see where the likely landing point of the improvised raft was, as it's an accurate model of the tides and flows of the area :)

I studied a huge amount of Hydrology at University but haven't touched it in the ~4 years since. This has made me want to go back to doing things that aren't just sat in front of a computer...

Wow. USGS has a store with this poster: https://store.usgs.gov/b2c_usgs/catalog/setCurrentItem/(isQu...

In case that brutal link doesn't work: go to https://store.usgs.gov/ and search for "Under the Golden Gate Bridge".

The poster is basically 1M^2 so is a decent size.

EDIT: Not 1M^3, but 1M^2. We'll have to wait for the 1M^3 version...

http://pubs.usgs.gov/sim/2006/2917/sim2917.pdf

Yes, but you have to print it yourself. The point of my post was the hopefully you could get a lovely print for $10 from a government store.

Better link:

https://store.usgs.gov/b2c_usgs/catalog/query/()/.do?query=u... (less brutal)

>The water depths have a 4x vertical exaggeration while the land areas have a 2x vertical exaggeration.

Can someone clarify what this means?

Water 1m below the sea surface is drawn like 4m deep. Land 1m above the seal level is drawn like it is 2m high.

ok thanks for the explanation =)

but why? I guess to improve the "readability" of the map to the human eye?

[edit] Never mind: https://en.wikipedia.org/wiki/Vertical_exaggeration

So, there is a rock jutting up just inside the bay from the gate, right out of the tidal channel to what looks like 40-60 feet. That is PERFECT for king salmon fishing I'm betting. Usually I go outside the gate, but right there as the tide comes in? Probably filled with fish.

Only problem is it is right in the sea lanes!

Gorgeous. Anyone have any tips on printing this in high quality?

Had the same thought. See my comment elsewhere in the thread. Turns out that the USGS sells posters.

I know a professional printer who prints my maps (http://www.wellingtonstravel.com) and is really good quality. Or you can find a local printer who can help.

I have found some more information in 2010. http://ww2.kqed.org/quest/2010/10/14/sand-waves-and-the-gold...

Needs a (2006), but this is super cool.

For geology, 10 years is much like a second for human.

It says 'meter scale'. I would think accounting for tidal heights with gps and other sensors, silt drift while scanning, they would be getting 'half-meter' minimum. I am not a geophysical studen...just thought they would get better resolution.

They're referring to spatial resolution, not vertical resolution.

In other words, they're taking about the size of the pixels.

Thank you for that out to me. I should have known better with my familiarity with mapping! Makes sense.

Anyone knows what 3D visualization software may have been used to generated these views?

Given the timing and who's involved, I'd guess it's probably Fledermaus. ArcScene is another possibility, but at that time, it struggled heavily with high quality output. These days, there are a number of other options.(Fledermaus is still quite nice, though!)

well i guess the idea i had for creating wall to retain elevating water out of the bay is never going to work now.

RIP inland bay area real estate when the water levels raise. :(

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