Wednesday, November 25, 2015

Search Challenge (11/25/15): How can you search all the coasts?

Yes, it really is hard to search... 

... all of the coastlines of all the world.  In the comments on last week's Challenge, a few readers (looking at you, Remmij!) expressed skepticism that my approach would work in general.  And in general, that's true.  

However, that particular Challenge had enough constraints baked into it (the coastline at such an angle, the clearly undeveloped countryside, the striking red color of the earth), that I thought it would be possible to do "manual" search. And, it actually worked!  We found it.  

Obviously, searching for a different aerial image might make it impossible to find.  Suppose instead I'd asked about this shoreline: 

A random stretch of coastline, tough to find by just scanning.  

That would be a lot more difficult.  This is clearly a north-south road near the shore, but it could be anywhere in North or South America, parts of Europe, even parts of Japan and Africa would have to be scanned. 

So, can we find a tool or database that would let us figure this out? 

Here's Part 1 of this week's Search Challenge.  (And I warn you; I haven't figured this one out, so it could be tricky. On the other hand, this is Thanksgiving weekend in the US, so I hope to have some time to experiment along with you.)  

1.  Can you find a tool, database, or some way to rapidly scan ALL of the coastlines of the world looking for 100 km wide sections of coast that run northwest-to-southeast?  (Such as we saw in last week's image.)  For this week, all we care about is if the coastline runs mostly "down to the right" at roughly -30 degrees (or course, that's the same as "up to the left" at +30 degrees).  For instance, on last week's image, this part of the coastline would match: 

Or, in that part of Madagascar there are really only 2 places that match this criterion, the arrow on the left in the following image is the same as the above, just zoomed way out: 

And... for people who want to work on something slightly less intense, here's a second Challenge: 

2.  The first picture above shows a stretch of the California coastline not far from where I live.  It's a region called "Devil's Slide" which has a tunnel running through a piece of the coastline that perpetually falls into the sea, usually taking the road with it, hence the name.  The Challenge is to identify the building that's near the southern exit of the tunnel.  This is what it looks like now.  Challenge:  WHAT was that building originally?  Who built it, and when? 

Here's what it looks like now. 

Streetview of the strange building (just above the "no parking" sign)

Let us know how you came up with the answer!  

And, as I said, if you're working on #1, I don't yet know if it's easily answerable or not.  It really IS a SearchResearch Challenge!  

Search on!  


  1. For question #2 here is my search path

    For #1 I searched for [ scan an earth map for features ]

    The term [ georeference ] might be helpful in finding a tool.

  2. Good day, Dr. Russell and everyone.


    Q1 is hard so need to think more about it.

    For Q2.

    Your bunker1 photo adding [devil's slide california] in Search by image. And same procedure with text [devil's slide california intext:bunker]

    The bunker on Devil's Peak was originally built during World War II...

    Google Map

    [devil's slide california intext:bunker] without image

    Devil’s Slide: Deserted Bay Area WWII Bunker Hovers in Midair

    Devils Slide military bunker a 'ghostly' reminder of World War II Source 1.

    [devils slide california military]

    There are 2 sets of bunkers


    The Challenge is to identify the building that's near the southern exit of the tunnel. This is what it looks like now. Challenge: WHAT was that building originally? Who built it, and when?

    A. Built as a triangulation and observing station in ...was abandoned in 1949.

    Source 1 says: "The bunker, the centerpiece of Little Devils Slide Military Reservation, was one of five "fire control stations" built by the Army at Devils Slide between Pacifica and Half Moon Bay...Army began constructing in the 1930s..."

    Happy Thanks Giving Day in advance!

    1. [devil's slide california intext:bunker 1938..1949]
      [devil's slide california 1938..1949]
      Devil’s Slide Coast History 1769..2015

      San Francisco Coastal Drive - Pictures & Map

      Reading links found something about "restaurant" so [devil's slide california bunker restaurant]

      "Mitch Postel, president of the San Mateo County History Museum, elaborates: “It was one of the buildings that formed part of the radar facilities that all hooked to guns north of there, like the 16 inch guns at Fort Funston.”"

      Image from those days "...This bunker was originally embedded in a hill, but Mr. Wiebe planned to build a restaurant on the site and he began tearing down the hill for a building. However, after removing the rock around the bunker, he could not obtain the water and electricity to continue the project...."

  3. I tried searching your anonymous shoreline with search by image to try the question I made in previous challenge about Earthview. Your photo adding didn't work in this case. And, a simple search by image gives answer Tom Lantos Tunnels California.

    As always, learning new things and having super fun!

    1. [world coastlines northwest-to-southeast database]

      World Data Service for Geophysics Shoreline/Coastline Resources links to different tools like:

      Tool 1

      Tool 2

      [world coastlines northwest-to-southeast finding]

      Where am I? Mapping a New World

      [world coastlines identification finding tool]

      2.26 Digitizing High-Resolution Coastlines in Google Earth

  4. "A random stretch of coastline, tough to find by just scanning."
    Edun Cove, 2015

    … but you are correct, my tool finding ability is near-nil, hence the Darwinian cranial target I suppose… a supposed CIA hacker I know steered me
    to a data set that indicated the above costal bit was in Patagonia - that might answer some questions, but the DARPA tool keeps locking up
    the Chrome browser… such is the way of things — enjoy T-Day where ever you are, S.F., Phoenix or Antananarivo… ground truth/minced perception, always tasty side dishes.
    Back to watching Adele as directed by my tech minders (she has replaced cats & goats for the moment…) -
    HELL O - forever in my ear

    working backward - on 2…
    the inside of the bunker
    recent (11/25/15)article
    good local history synopsis, additional pics
    lousy sound - turn it off - gives a sense of the area
    YT view from the road
    Caltrans info
    Tom Lantos tunnels|wiki

  5. #1 Image Search >Wikimapia
    Coordinates: 37°34'37"N 122°30'45"W
    Confirm in Google Maps with satellite image -matched to the coastal contours.

  6. forgot to say that, like Ramón, I did an image search on your 'random' coastline before seeing you identified it further into the text - got this too:
    1st image

    Fred's links led to this interesting, albeit non-coastal, Goo Earth info bit… scans take months as they zoom…
    Pareidolia — WotD
    daily mail
    onformative source
    they are doing some eye teasing work
    their feed
    in Amsterdam - read thru to 'Screams for Munch'

    fwiw - the previous post - should have read 'coastal', not 'costal' - thumbs are non-functioning… spelling, lack of tools|apps responsible for my personal decline and that of Western Civilization…
    and maybe a couple other thingy-doohickies…

    darn DARPA tool? keeps freezing Chrome, wuwt? or is it the EXIF extension update?

    this might be of tertiary interest
    dyslexic - Giving Thanks Night to all…

    note: not for those with easily offended sensibilities… "Here be dragons - Hic sunt dracones" and unicorns
    …the most perplexing, and daresay, the most disturbing coastline images I've spied today —
    I'll leave you to ascertain the plausibility of such images… YT might be involved…
    perhaps the suggestion is such coastal finds are rare as unicorns… search has to have some humor to it, right? (the Goo ads for this are haunting me on every site)
    make it go away Google ads
    they're too small to see on your mobile smartphone anyway

    fwiw, a historical note as we race into the non-present:
    "Dr. Amdahl rose from South Dakota farm country, where he attended a one-room school without electricity, to become the epitome of a generation of computer pioneers who combined intellectual brilliance, managerial skill and entrepreneurial vigor to fuel the early growth of the industry."
    good bit of history

    on a much more somber note - Fred may be interested too -
    since you have exposure to Henry M. Gunn High School

  7. Question 2:

    I noticed that the pictures were called bunker1.jpg, bunker2.jpg etc. so started with a web search [devil's slide california bunkers south end tunnel] and got a result list headed by the Wikipedia article about the Devil's Slide that included a Military History section. It told me that there were 6 such structures built in WW2 as triangulation stations for defending San Francisco. To find the specific bunker in the challenge picture I went to Google Maps and found the Tom Lantos Tunnels (also mentioned in the WP article), than looked for where it ends just north of the coast. There's a Bunker on the map, and when you click on it there are photos including one that looks identical to bunker1.jpg. The address is given as Half Moon Bay, CA 94019, United States.

  8. "…However, that particular Challenge had enough constraints baked into it (the coastline at such an angle, the clearly undeveloped countryside, the striking red color of the earth)"
    a contender?
    answer - a bit northeast
    hard to spot from a 1000 miles
    intriguing bit of shallow/deep coast from 1000 feet - some red, more development
    had to go back a bit for the shoreline of Kansas
    prior to GooMaps
    the OK Vikings

  9. I don't have an answer to question #1, but I do it reminds of a similar research challenge that I was once faced with, I had video of someone shovelling snow outside of their house in Toronto. From the video you could tell what the house number they lived in, that all the houses on the street were single story with driveways up to garages on the front of the house, you could also tell that the street curved out of sight on one end, and had a 'T' Junction on the other end, and between the house and the T Junction and another street crossed this street. However, the video did not reveal the name of the street.

    I spent a bunch of time looking on Google Maps, checking out street view, and looking for that house so I could find the specific address, but never found the house. I left wondering if there was a tool that would identify that particular patter of roads (Curves, T Junctions and Cross Streets) in Toronto. Although on the face it is a different sort of challenge as looking for coast lines, it is similar in that it would be a tool that identifies specific patterns.

    1. I still don't have an answer to question #1, but I was thinking about it more, and I have feeling that telling what is a coast line from an aerial photo is one of those problem that is easier for a human than a computer (like those images that pop up in Captchas).

      My thinking is that rather than looking for a tool that analyzes photos it might make more sense to look for a tool that analyzes shapefiles. It looks like you can download a shapefile of all the worlds coast lines here:

      I am not very experienced with coding, so I don't know if it could analyze a shapefile of coastlines looking for a specific pattern,It looks like there is a package for R called 'spatstat' that is designed "for spatial statistics with a strong focus on analyzing spatial point patterns in 2D." Anyone know if this would do the trick?

      If that isn't it, I would look for either some sort of code, or tool for ArcGIS or QGIS that would analyze shapefiles looking for patterns.

    2. The other line of thinking I was perusing was asking which kinds of people might need such a tool, and then look for those people. But I haven't really figured out a lot of places where this sort of tool would be applied.