Sunday, December 30, 2012

Researching With Google Earth – Part Two



Researching With Google Earth – Part Two
Looking for a  clear visual sense of the places you’re writing about (and can’t afford to visit in person)?  This series of Finding Stuff posts shows you how to use Google Earth for effective location visualizations (download the free program here

The Task At Hand

For the purposes of these posts, the terrain we’re exploring is Flanders, Belgium, the site of some of the heaviest fighting between German and Allied forces during World War I. Specifically, we’re trying to find, and define, a line of nineteen huge mines dug by the British Army, which they filled with nearly a million pounds of high explosives, and simultaneously detonated under German positions on June 7, 1917. 

Please review the text and screen shots of Part One for techniques on creating a general Google Earth overview of a region, using user uploaded photos, pinning a placemark, and driving around with Google Street View.

We had gotten up to the three at Kruisstraat, so that leaves just five more to plot: Ontario Farm, Trench 127 (#1 and #2) and Factory Farm (#1 and #2). Now all nineteen are placemarked and ready to be linked.

Measuring Distances

Have you ever needed to know the distance between two points? Google Earth’s measuring tool makes this a snap, and the results are available in eleven different units of measurement: Centimeters, Kilometers, Inches, Feet, Yards, Miles, Nautical Miles, Degrees, Arcseconds, and Smoots (a unit created as a practical joke by MIT students in 1958, who used the height of freshman Oliver Smoot to measure the length of the Harvard Bridge. Google reckons a smoot is 67 inches (1.7018 meters).

As you’ll recall from the last post, we located a mine crater at a place called Spanbroekmolen. You may also recall that the British Army “moles” (as the tunnelers called themselves) dug a 1,700 foot tunnel to reach the spot they reckoned was right below a fortified German bunker. The question begs: where was the entrance to the tunnel? We’re going to run a digital tape measure to look at the possibilities.



On Google Earth’s menu bar you’ll find a ruler icon. Click on that and the Ruler window pops up. Choose “Line,” and choose “Feet.” Place the cursor at the center of the mine crater and run a line out 1,700 feet to the south. Keeping the left mouse button held down, swing an arc and you’ll get a good visual sense of the spots the moles might have picked to start their tunnel. The little copse of trees to the south-southwest is as good a place as any to release the mouse button. Due to the obliteration of the countryside by three years of war, there is little likelihood that anything remotely resembling a tree stood there in 1917. But you get the idea.

Not happy with your line? Just click on “Clear” and run it again. Happy? Click on “Save.” This brings up another window that, among other things, lets you choose the color and thickness of the line, and give the feature a name. When you’re done, click “OK” and your line is fixed in place.

In the last post we spent a little time at the Kruisstraat craters. You can use the Ruler tool to measure their widths. The larger is pretty big—228 by 217 feet. In this case, there’s really no point in saving the line, so just close the Ruler window. We can do the same thing to measure the distance from Spanbroekmolen to Kruisstraat. Center to center it comes up at 632 yards (or 339.42 smoots).


The explosion of the nineteen mines was so loud that it was reported to have been heard by British Prime Minister David Lloyd George, who that morning was at his house south of London, near Walton Heath, Surrey. A quick Google Earth measurement from the heath to the mine line tells us that the distance is 140 air miles. It must have been one very loud bang.

As a side note, the firing of the mines was the largest manmade explosion in the history of the world, until the Trinity A-Bomb test in 1945.

Marking Pathways

By using the Ruler tool you can also trace continuous freehand paths on the map imagery. The picture below shows a freehand rendition of the Allied (turquoise) and German (orange) front lines in 1917 (data for these came from a WWI British trench map). This sort of drawing is not 100% accurate, but consider it a fair graphic representation of the situation on the ground. Run a ruler and you can see that in some places the trench lines were within a hundred yards of each other.


You can also use Add Path to run graphic lines. That’s the icon at the top Menu Bar with two lines and three dots. This is the measuring tool we’ll use to connect the nineteen mines.
Left click on the starting point (Hill 60 #1 and #2) and release. Cursor down to St Eloi, left click and release. A line from point A to point B appears. Move to Hollandsches Farm and do the same. A line from B to C appears. Repeat all the way around until you reach the Factory Farm mine craters. You should now have a continuous path that touches on each of the mines. Before naming and saving, check the distance. It ought to be 8.07 miles. And now we're accomplished our mission: plotting the arc of mines.


The Add Path tool can be very useful for making all sorts of graphic depictions—tracing abandoned railway lines, creek beds, otherwise faint trails. You can even use it to trace the placement of a long gone building.

Determining Altitudes/Elevations

Google Earth is pretty good about measuring altitudes, and hence, topographic elevations. Going back again to Spanbroekmolen, we want to know difference in height between the German bunker and the British tunnel entrance. You’ll notice at the bottom center of the screen strings of numbers that move whenever you move the cursor. The one on the right is elevation. The center of the old mine crater is at an altitude of 239 feet. The tunnel entrance that we guessed at earlier, is 152—a difference of 87 feet (high ground always gives the defender a tactical advantage).

Flanders is famous for its scenic rolling landscape. But even the slightest elevation could be hell in battle. After the mines exploded on June 7, British Army troops had to storm up the hill, past the smoking Spanbroekmolen crater, down another slope, across a flat barely 400 yards wide, and back up yet another hill to reach their objective, the village of Wytschaete. As Google Earth tells us, the change in elevation for troops in that sector was about 70 feet.
You can also use the elevation tool to measure the depth of bodies of water (works best with oceans and seas).

One of the features missing from Google Earth is elevation contours. If you’re familiar with USGS-type topographic maps, you know that they have wavy lines that signify gradients. These can be really helpful for getting a sense of the overall terrain. In Earth you have to roll the cursor all over the image and watch the elevation number change to get a less clear sense of the lay of the land. Street View, if available, can be a useful tool for seeing how the terrain is laid out. And to a lesser extent, so can the 2D Ground View. (n.b.: a beta-test feature is being added to Google Maps that will let you see contours, but it’s availability is currently very limited).

Locating Places Using Latitude and Longitude

What if you only have a site’s latitude and longitude? Google Earth is beautifully set up to handle this. And it’s a feature especially useful when measuring over bodies of water.
Let’s track the positions of an American submarine wolf pack in the Luzon Strait (the "Devil's Sea") off the northern coast of the Philippines in May 1944. They were stalking a Japanese merchant convoy, MI-11, that had sailed from Japan, headed for Brunei.

All we know about the subs’ locations at any given time was their latitude and longitude as noted in their after action reports. From recently declassified intelligence reports we also know the estimated noon positions of the convoy. These documents were acquired at National Archives II in College Park, Maryland.

The first sub to spot the convoy was USS Hammerhead, at 5:31am on May 30th, at location 20° 52’ North, 120° 47’ East. 



Move over to the Fly To search box on the far upper left. Enter the position like this: 20 52N 120 47E (you don’t need symbols like degrees, minutes, or periods). Click go and the cursor will move to the spot. Drop a placemark and name it. As for Hammerhead’s track after this, we know she left the area, so we’ve drawn in a path line to represent her course.



There are no other useful entries for Hammerhead, so we move on to Parche, Steelhead, and the ships of convoy MI-11. Here’s the finished image:


Accurately plotting courses, particularly in one of the most famous submarine actions of WWII, is painstaking work. The chart in the screen capture above took about 12 hours to create, with lots of checking and double-checking. But when it was finished it gave a complete picture of the battle, and helped to clear up decades of confusion over who was where, when.

Tip: If you need to be really precise, you can add seconds to the values you input: 20 52 19.07N 120 47 12.6E.

In a future post we’ll discuss how to use Google Maps and Bing Maps for Finding Stuff. But the next post will explore how to take advantage of the proliferation of historical digital archival repositories since the advent of the Internet.
If this post was helpful or interesting to you, please let me know. I’m always looking for ways to improve the blog.

Sunday, December 23, 2012

Researching With Google Earth – Part One



Google Earth can be a great research tool for writers. You can use it to get a clear visual sense of the places you’re writing about. Let’s take a look at some of the methods to accomplish this (you can download the free program here: http://www.google.com/earth/index.html). 

The Task At Hand

For the purposes of this post, the terrain we’ll explore is Flanders, Belgium, the site of some of the heaviest fighting between German and Allied forces during World War I. Specifically, we’ll be trying to find, and define, a line of nineteen huge mines dug by the British Army, which they filled with hundreds of thousands of pounds of high explosives, and simultaneously detonated under German positions on June 7, 1917.


General Geographic Overview: Let’s start by getting a sense of Flanders, the Dutch-speaking region of Northern Belgium. 

Typing “Flanders” into the Google Earth search box is not productive—it starts to zoom in on a hotel in Brugge. We know from our textual research that the British placed their mines in an eight-mile arc a few miles south of the Flemish market town of Iper (known as Ypres during the Great War). So, type “Iper” into the Earth search box and click go. 

When the map stops moving, zoom out manually to an altitude of about 170 miles (“eye altitude” is shown in the bottom right corner). At this point the image you’re viewing is just plain terrain, revealing few geographic features. We can fix that. On the left hand side of the screen is a menu box. Go down toward the bottom, where it says “Layers,” and tick “Borders and Labels,” “Photos,” and “Roads.” When these items appear you’ll have a clearer contextual picture of the region. You’ll see Brussels off to the east and Dunkirk to the northwest. On the far left, across the English Channel, you might be able to see the White Cliffs of Dover in Southeast England. This, then, is an overview of the area we’re focusing on.


Zoom In on the Action

Our textual research turned up a list of the British mines and a crude hand drawn map of their locations (see the complete list at the end of the post). At the top of the arc the first two, were designated Hill 60 #1 and #2. Google Earth is so smart (well, sometimes at least) . . . if you search for “Hill 60 Belgium” the map will find a location it knows as “Battle of Hill 60.” Zoom in a little more and start looking for a pair of dark blobs that are incongruent with the otherwise verdant, park-like setting. A number of little blue-brown square box icons also appear.


 User Photos

These icons indicate a photograph that has been added by some diligent Google Earth user. Sometimes a site will have dozens of photos, which are very helpful for visualizing what a place actually looks like. Clicking on those squares clustering around Hill 60 reveals several images of what appear to be pleasant little ponds. They are, in fact, the craters left by the British mines when they were detonated that warm June morning nearly a century ago. 


Setting A Placemark

Now that we’ve found these craters, we should mark their locations. Cursor up to the Earth menu bar and click on the yellow pin icon. This brings up the “Placemark” menu. Pick a color (yellow is good), and a size (1.1 is good). This action brings up a pin in a flashing box. Move the pin over to one of the craters. Under “Name” type in something like “Hill 60 #1,” then click OK. That will fix the pin’s placement. Repeat the process for the second crater.

Cross-Country Searching
Our list of mines shows that the next one is near the village of St Eloi. An Earth search turned up a bunch of “Rues St Eloi,” but not a town, so a manual cross-country search is in order. Cursoring around the fields south of Iper you should stumble across “Sint-Elooi.” That’s probably our place. So zoom in and look for a crater. Yikes, there are two. Which is the right one? Helpfully, there’s another one of those photograph icons next to one of them. A click on that reveals our krater. So drop a pin.

A trio of mines is next on the list: “Hollandsches Farm.” An Earth word search shows nothing. So it’s back to the cursor. Start moving cross-country (keeping in mind the mine line was an arc) looking for farms with three ponds. Any number of them have one or two, but they lack the circularity of a mine crater. There are no photo icons to check. Damn.

Back in the first post I mentioned PPIPatience, Perseverance, Imagination. If you’re set on finding the Hollandsches site your search will require all three. But here’s a cheat: find the town of Wytschaete and follow the northwest road about one mile. See the three ponds clustered around the farm buildings? Pin and label these. While you’re there you can count the cows in the fields.

Now the arc of mines takes a slight inward jag. But the pair of craters called “Petit Bois #1 and #2,” are so large they stand out pretty clearly. “Maedelstede Farm” will be a little harder to find – it’s smaller. When you do find it note that the farm road, which was straight before WWI, now has a kink to go around the crater. The next mine, “Peckham,” is larger, and thus easier to find.

Which brings us to the eleventh, called “Spanbroekmolen.” 

At this location the British Army dug a 1,700 foot tunnel under a heavily fortified German bunker, and at the end of it they stacked the equivalent of 200,000 sticks of dynamite. The blast obliterated the fort, creating a crater 250 wide and nearly 80 feet deep. Today the huge hole in the ground is a war memorial, surrounded by thick bands of mature trees and known as the “Pool of Peace.” Notice that there’s also a kink in the road here.


Let’s move on to a pair of mines called Kruisstraat #1 and #2 (there was a #3, but it was filled in years ago). 


While you were visiting Spanbroekmolen you may have noticed that it fronts on Kruisstraat Road. So if you follow the pavement for a ways you’ll find the craters (which their owner now stocks with fish).

If you click on the photo icon at the bottom of the second crater you’ll see this image of old shells. The shifting sands of Flanders are still regurgitating these even now.


What does Kruisstraat look like at ground level? 

Putting Google Earth Street View Through Its Paces

As you probably know, these sets of images derive from a series of photos made from moving automobiles fitted out with 360°-worth of cameras (currently fifteen), and recorded on hard drives. Many locations around the world are covered, but by no means all, so this feature may be unavailable for the places you’re researching.

To get into Street View, move over to the far right, under the compass. There you’ll find an icon of an orange person. Click and drag it to the Kruisstraat craters. You’ll notice as you’re dragging that certain roads become outlined in blue. These indicate where Street View works. No blue, no view. Release the mouse on the road and all of a sudden you’re actually there.

Tip: If you don’t drop the icon on a blue road the “Ground View” mode will activate. This shows a 2D ground-level representation of the aerial map image and, frankly, is not particularly useful for researchers. 


Left click to pan or tilt View, and use the mouse wheel to move forward or backward along the road (no off-roading, yet). The two mine craters are clearly visible along the side of the road.

A 360° pan will help you visualize the area’s topography. With the compass almost due east, on a small rise you’ll see a church steeple. This is the town of Messines, for which the great battle of June 1917 was named. Pan left across the ridge and almost due west you’ll see a tall hill. That’s Mount Kemmel, which was a key observation point for the British Army.

Notice how green everything is. A century ago this entire area was like a moonscape—pounded into a treeless, muddy hell by years of bombardment (just in the week-long run-up to the 1917 battle the British fired nearly three million shells at the Germans emplaced along Messines Ridge).

Continue driving up the road toward the town, but watch out for the cyclist!


 If you’re feeling peckish, View-drive into Messines. In the central Markt square you can grab a virtual lunch at the CafĂ© a Centre (the yellow building on the right). The digital waterzooi is reputed to be excellent.


Here’s a Quick Summary of Finding Stuff Using Google Earth as a Research Tool – Part Two

  Creating a General Overview of a Region.

  Using User Photos to see what places actually look like.

  Pinning a Placemark.

  Driving around locations using Street View.


Next time we’ll finish up plotting the mine line with Google Earth, when we cover measuring distances, marking pathways, determining altitudes (and hence, topographic features), and locating places using latitude and longitude. Thanks for tuning in.

If this post was helpful or interesting to you, please let me know. I’m always looking for ways to improve the site.

List of British Mines, Battle of Messines, June 7, 1917
Hill 60 #1                     Hill 60 #2                     St Eloi                         Hollandsches #1
Hollandsches #2         Hollandsches #3          Petit Bois #1               Petit Bois #2
Maedelstede Farm      Peckham                     Spanbroekmolen        Kruisstraat #1 
Kruisstraat #2              Kruisstraat #3              Ontario Farm              Trench 127 #1
Trench 127 #2             Factory Farm #1          Factory Farm #2

An Introduction to Researching With Google Earth



After seven days of incessant bombardment, at exactly 3:06am on June 7, 1917, it got very quiet in the trenches along Flanders’ Messines Ridge. “Perfect stillness,” wrote one soldier. “Perfect stillness.” The silence was so profound birds could be heard singing in the night. It spooked soldiers on both sides.

Four minutes later that stillness ended abruptly. From Hill 60 on the north to Factory Farm on the south, nineteen mines went up in spectacular synchronicity. Hundreds of thousands of pounds of high explosive rent the earth along an eight-mile front, instantly killing thousands of German soldiers. The pillars of fire inspired awe in all who witnessed them. 

If you were writing about this event you main sources would be books, newspapers, and Internet sites. But what if you wanted to know what Flanders looks like? Is it flat, hilly, urban, rural? What about the roads and railways? 

Is there a way to visualize the topography of the Flanders front and the positions of those nineteen mines?

British Army WWI “trench maps” would be a starting point. They show great detail; even show the zig-zaggy trench positions. But these maps cover tiny quadrants, and it would take a dozen or more to cover the ground of that awesome ring of fire. Stanford’s, a wonderful map store in London, sells individual trench maps for $5.00. Are you willing to spend $60 or more, plus freight? Is there another way?

Yes. And it’s much closer at hand: Google Earth.


This tool was first introduced by Google early this century. It is essentially a vast collection of satellite images, aerial photographs, and GIS (Geographic Information System) 3D data that covers the entire globe. 


Google Earth vs. Google Maps

Google Maps is essentially a digital road map application, and is accessible on any browser (https://maps.google.com). Its default map features some very basic topographic relief, and as you zoom in, shows considerable road detail, including street names. It has a complete directions module that will tell you how to get from point A to point B (and, C, D, E, etc., too, if you want). For a growing number of areas, by pointing on the “Satellite” box on the upper right, then clicking “Terrain” you can intensify the relief details to get a pretty clear idea of the lay of the land. And by zooming in with this mode you can see contour lines and their elevations, just like on a USGS topo map—a useful feature. The latest iteration of Google Maps lets you display Google Earth imagery, but you cannot access any of the topographic tools. In a later post we’ll discuss researching with Google Maps in more detail, as Google has just added a bunch of new, useful features.

Google Earth is the application that we’ll be studying in the next two installments. It’s a standalone imaging program (that you need to download and install—easy and free, find it here: http://www.google.com/earth/index.html). Earth can be map-like, but its real value to a researcher or writer lies in providing accurate visual images (aerial and otherwise) of particular locations, including roads, buildings, landmarks, trails, fence lines, copses, terrain, elevations, and much more. For the purposes of this post we’ll concentrate on Google Earth.


The Eight Features of Google Earth That are of Most Use to Writers

  Provides a general geographic overview.

  Has collections of location photographs uploaded by Google Earth users and embedded into the topo images.

  Allows you to set a placemark by dropping a pin on a point and identifying it with a label.

  Street View lets you hop in one of Google’s photo cars and drive through cities, towns, villages, fields, and mountains, with 360° panoramic views.

  The ability to accurately measure distances between points.

  The ability to measure elevations (though less accurately than horizontal planes).

  The ability to draw your own pathways.

  The ability to find a location using only latitude and longitude (helpful at sea).

How does all this imagery help a writer? 

Before we attack Flanders, let’s shift briefly to a different continent. Say your key nonfiction subject grew up in Redwood City, California—a place you’ve never visited. Using Google Earth you can find out what the town and its environs look like. Have a street address? Type it in and find her house. Hop into Street View and drive down his road. Check out her school, his favorite playground, where dad worked. 

Writing fiction? You can do exactly the same thing. Choose a neighborhood, a specific house you think is just right for your protagonist, the school you want him to go to, the playground you want her to play at. You can accurately visualize the relationship that the mountains and the bay have with the town—then wax eloquently about the scene.

The next Finding Stuff post is going to be chock-a-block full of stuff on how to do all this, so stay tuned for our Google Earth visual visit to the fields of Flanders.

*Important Note: When you download Google Earth the default setting will concurrently download Google’s Chrome and make it your default web browser—unless you tell it not to. Be sure to uncheck the two boxes on the “Terms of Service” page. If you don’t, Chrome will be the devil to get rid of.