Posts Tagged ‘maps’

Eureka contaminated sites

Another useful Google Earth feature today: the Contaminated Sites layer from Terradex. This company compiled, and makes available free online, a list of USEPA Superfund and RCRA Cleanup sites, and state sites including California, Oregon, Washington and New Jersey.

The layer requires the use of Google Earth 4 or later. When you click on individual sites, the description includes links to websites and a comment box to provide feedback on the sites. There are 130,000 sites shown, and zooming into regions will reveal more sites.

It’s quite interesting if you like to find out what goes on in your community and know about the quality of your environment. Alas, I don’t think it’s been updated in a while; some of the site clean-ups marked as still open may have been completed by now.


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The various stages of collapse of the Wilkins Ice Shelf in the Antarctica has been in the news over the past couple of weeks.  Now you can watch an animation of the process in Google Earth, as assembled by the National Snow and Ice Data Center (NSIDC).

After downloading the file and opening it with Google Earth, I recommend first clicking the little clock icon to the left of the slider bar in the image, moving the animation speed slider so it is about 1/3 of the way from the left, and selecting “At end of time range, animation should stop.”  Then click “OK” and press the play button (arrow) at the right of the slider.  Repeat as needed.

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In Monday’s post I talked about the North Coast Geotourism form through which you can submit locations of interest; on Tuesday I mentioned that the only tricky part of the form was getting the latitude and longitude coordinates, and on Tuesday I explained how to do this online.

If you want some background on what latitude and longitude mean, read on. You don’t need any of what follows in order to locate the coordinates of a point — only to understand what these coordinates mean; but if you are interested in the background, this is for you.

They are those lines you see drawn on maps and globes. Imagine the Earth has been sliced in wedges like an orange, from its North Pole to its South Pole; each cut would represent a meridian. The imaginary “slice” line on which the Greenwich observatory sits, in England, is by international convention the prime meridian, our “zero” meridian.

Next, imagine that the Earth is also sliced in the other direction, but in parallel slices instead of wedges, in lines that cut slices of even thickness from North to South. Each line is called, aptly enough, a parallel. The line going through the Equator, at the exact same distance from both poles and where the Earth’s girt is thickest, is the “zero”. You can see a picture map of the results here, with the Earth semi-unwrapped and flattened.

When we talk about the latitude of a point, we mean its distance, North or South, from the Equator, with 90 degrees between the Equator and each pole; which is the same as asking which parallel it is located on. A point located at exactly 45 degrees North is halfway between the Equator and the North Pole. Every point with the same latitude is on the same parallel circling the globe.

And when we talk about the longitude of a point, we mean its distance from the prime meridian, measured east or west from 0° (along the Greenwich meridian) to 180° (on the other side of the world from the Greenwich meridian). In other words, we’re talking about which meridian the point is located on.

With these two measurements, we can describe to location of any point on the surface of the globe. Why don’t we have the same “shape” for the lines encircling the globe in both directions (north to south, east to west)? Because there is a north pole and a south pole thanks to our planet’s rotation on its axis; but there is no east pole or west pole because the earth doesn’t spin in a second direction. The north-south axis represents a “real” line, something concrete if intangible.

Links of interest:

  • The Geographic Grid by Dr. Christine M. Rodrigue, California State University — Long Beach (CSULB)
  • Navigation — a chapter of the Pilot’s Handbook of Aeronautical Knowledge

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Some people find it daunting to orient themselves using a map. If you’re not used to this way of seeing the world, or to reading the symbols, it can be confusing at first. But I learned to read maps as a kid, to pass the time in the backseat of the family car when we went on vacation, so if a nine-year-old can, you can too.

What follows in this article is the step-by-step overview of how to find a spot on the map without an address.

Finding a location

Maps are two-dimensional representations of human and physical space that are packed with information; don’t try to take all this info at once. Instead, try orienting yourself in pretty much the same way you do in real life: start with a landmark you can easily recognize.

I like to start with a major road because they’re so well labelled. Once you’ve found a big road that goes somewhere in the vicinity or general direction of your site, find a second landmark that the road crosses; for example, a town, a major cross-street, etc. For all landmarks, pick ones whose position in relationship to your target site you understand well.

Now that you have these two helping points or lines to figure out where you are, follow the road as if you were walking or driving to your target site. Pay attention to cross-streets, and trace your steps back (or start over from the beginning) if you get lost.

For example, let’s say we want to go the beach near Orick, north of Redwood Creek, and we’re using Google Maps (or one of the applications based on it, like iTouchMap.com) to find the spot. First, let’s move the map around until California is roughly in the center of the map, and click on the “+” end of the scale bar to the left in order to zoom in. (Or, if your mouse has a scrolling wheel, position your cursor over the point you want to zoom on and scroll “up” to zoom in, “down” to zoom out.) We have to do this a few times, recentering on Northern California until we start seeing features we can recognize.

The first landmarks will be big name places like San Francisco and Portland. We know we’re in between, so we’ll zoom until we see Eureka appear, then Crescent City. We soon see U.S. 101 running up the coast, which helps us get situated.

We continue to focus progressively closer until we start seeing more place names we recognize — Arcata, McKinleyville, Trinidad, Klamath — and position our next zoom as close as we can north or south of those known locations. At last, we see Orick’s name appear and we can focus on that area.

If we were using a paper map, we would also start with something recognizable like U.S. 101 and start looking north from Eureka, or south from Crescent City, along the road until we saw more familiar place names. Say we’re moving north from Eureka, following U.S. 101. Even if we miss Orick, once we see Klamath or Crescent City, we know we’ve gone too far and need to trace our path back along the road until we spot Orick.

Either way, we see Orick there in the little bend U.S. 101 makes, just north of Freshwater Lagoon and before crossing the swath of Redwood National and State Parks that encompasses Prairie Creek. If we’re using a paper map, we may be limited in how much detail we can see, but with on-line mapping we have the luxury of great detail. We can continue to zoom on the Orick area until it starts filling the map. As we zoom, we notice that new levels of details, such as roads, appear only at certain zoom levels.

Now, from going there before, we remember (for example) that the beach access we were thinking of was on the north side of Redwood Creek. So we’ll get close and follow U.S. 101 until it crosses the creek, then take the first side road that heads west toward the coast; that’s Hufford Road. We might have to do this a few times if we pick the wrong road, but this time it will work. We keep following Hufford Road, a very small road that becomes a dirt track, until we reach the beach.

And in Google Maps, or iTouchMap or Google Earth, we can click to put a marker there. In iTouchMap, we can see the point’s longitude and latitude by clicking on the point or by scrolling down below the map. Voilà, we’ve located a geographic feature without having an address.

Map symbols

All maps use symbols to represent information about the geography they cover. For example, maps usually show cities and towns with dots of different sizes corresponding to their population, and roads with different widths and colours depending on their importance, paving, and number of lanes.

Maps may also use symbols to indicate all sorts of information, such as the presence of tourist attractions (golf course, lookout points, vistas, rest areas, supervised beaches, campgrounds, etc.); emergency facilities (hospitals, police stations, fire stations, etc.); other man-made features (railroads, dams, churches, mines, etc.); natural features and ground cover (rivers, ponds, wetlands, forested areas, etc.); and terrain (especially through the use of contour lines, hatching, and shading).

Paper maps sport a “legend“, that is, a list of all the symbols used and their meaning, usually in a corner. Here are a couple of sites showing the symbols used on topographic maps from the U.S. Geological Survey (USGS) and Natural Resources Canada. Topo maps are some of the more densely packed with information.

Online mapping applications may not display a legend because they can allow the viewer to click on features in order to identify them. They also offer another way to convey information to the user: most offer choices of different views of the area covered.

For example, Google Maps and its derivatives offer a choice between the “Map” view (a graphical representation of the area), the “Satellite” view (photo representation), a “Hybrid” view (aerial photos with roads and symbols superimposed), and “Terrain” (a graphical representation that uses contour lines and shading to represent the three-dimensional shape of the terrain surface).  Note that each of these view is only available at certain levels of zooming.  (In both images I showed above, I used the Hybrid view.)

You can switch back and forth between views; some people find aerial photographs easier to understand because they show the world in true (or truer) colours, while other people find them confusing because they may show more detail than the viewer wants.

Coming up: What are latitude and longitude?

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On Monday I talked about the North Coast Geotourism project and how the public can submit sites. There is only one potentially slightly tricky question in the form for submitting sites: you need to provide the latitude and longitude of the site you’re submitting.

Gulp! The what? How do I do that? Well, as a first option, the North Coast Geotourism site sends you to a very handy tool, Geocoder.us (or Geocoder.net, which gets you to the same place). In Geocoder, you only need to enter the street address for most locations, and you will receive the latitude and longitude coordinates.

But what if you’re looking for the coordinates of a beach, or a waterfall, or some other site that doesn’t have a street address? Well, there are map-based solutions, primarily based on applications like Google Maps and MapQuest. One example is iTouchMap.com. To obtain the coordinates of any point:

  1. Use the map to navigate to the location of your choice (more on this in an upcoming post);
  2. Zoom in as much as you need to;
  3. With your mouse pointer, click to place a blue marker in the right spot.
  4. You can then click on the marker and the coordinates will be listed in a pop-up window.
  5. You can use your mouse cursor to highlight (select) the coordinates;
  6. By using the keyboard shortcuts (Ctrl + C for PCs) or by right-clicking with the mouse and using the context menu, you can copy the coordinates;
  7. Then go paste them (Ctrl + V) in the form.

There are other similar sites and other options, address- or map-based, such as the ones listed on Where Am I?

Finally, the most scrumptious toys of all are virtual globes like Google Earth and NASA’s World Wind. With these, you can navigate to the location of your choice and directly get coordinates, as well as a slew of far more interesting information, but they require installing the software to your computer and they are far more than you need if all you want is coordinates.

(In Google Earth, you can read the coordinates of your mouse cursor in the lower left-hand corner of the view pane; and you can obtain a point’s exact coordinates by right-clicking on its name in the left-hand panel and selecting “Properties”. You can then copy and paste the coordinates.)

Note that some sites, like iMapTouch.com, give decimal values in fractions of degree (e.g., 40.777162, -124.220695), while others provide a value in degrees, minutes, and seconds (40°46’37.78″N, 124°13’14.50″W). The North Coast Geotourism form will accept either.

Coming up: How to navigate a map

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Trinidad Beach in light fog -- Copyright 2009 Edmund Metheny

Trinidad Beach in light fog -- Copyright 2009 Edmund Metheny

A couple of weeks ago, the Crescent City Daily Triplicate introduced us to an exciting mapping project: the North Coast California Geotourism project, covering the Del Norte to Marin areas, including Lake County.

Working with the National Geographic Center for Sustainable Destinations, the North Coast Tourism Council and the U.S. Bureau of Land Management are compiling a Geotourism Map Guide. The NGCSD has already contributed large databases of fascinating information to Google Earth.

The Del Norte County Visitors Bureau is exploring this opportunity to make the North Coast shine in the public’s eye, along several other ideas to attract more tourism.

So what exactly does “geotourism” mean? According to the North Coast Geotourism project site:

Geotourism is defined as tourism that sustains or enhances the geographical character of a place—its environment, culture, aesthetics, heritage, and the well-being of its residents.

The project team is hoping to develop an online geotourism guide and database, and perhaps a paper (poster map) version as well. I expect the database will also be available in online mapping applications like Google Maps and Google Earth.

Through an online nomination form, anyone can submit a site: natural, cultural, and historic attractions, etc. You can also download and print the PDF form and fax it to (831) 647-4244, or mail it back to BLM California Coastal National Monument, 229 Foam Street, Monterey, CA 93940.

What kind of sites get listed? Here is a list of categories to draw from:

  • Natural area (river, waterfall, botanical, geologic feature)
  • Beach, tidepool, public pier or other coastal access
  • Cultural, traditional experience, museum or site
  • Native American Heritage Sites
  • Festivals, celebration, ceremony, or event
  • Historic site (fort, cemetery, church, shipwreck, etc.)
  • Arts, artisan, or handicrafts
  • Outdoor recreation (hiking, biking, kayaking, etc.)
  • Music, dance, theater, storytelling, etc.
  • Accommodation (B&B, lodge)
  • Culinary, cuisine (restaurant, café, wine bar, brew pub)
  • Visual attraction (scenic overlook, photo point, etc.)
  • Farm, agriculture, ranch, winery, etc.
  • Redwoods theme (hikes, groves, restoration, etc.)
  • Wildlife habitat and/or wildlife viewing
  • Locally or family-owned business
  • Scenic byway or drive
  • Eco-friendly (fish-friendly farming, carbon neutral, etc.)
  • Salmon theme (fish viewing area, hatchery, restoration efforts, river float trips, exhibits, etc. )

So why not take a few hours to sit with family or friends some weekend this month, list your favourite sites, and fill the form together to brag about the local “best kept secrets”? The form is very simple and there is even an example of filled form available on the Website to help guide answers.

The deadline for nominations was first set for March 30, but has been extended to May 31, 2009. For questions, call Marcia deChadenedes, Project Coordinator at 831-372-6225.

Links of interest:

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Switzerland-Italy border
Thanks to global climate change and the resulting world-wide glacier meltdown, Switzerland and Italy now have to redraw their border. The draft law has already been endorsed by the Italian Foreign Minister, Franco Frattini, and is expected to become law before the end of April; Switzewrland has already agreed to the new border.

The current border between the two countries was established in 1861, and is very convoluted as it follows the Alps’ ridgelines and glaciers. The glaciers are now retreating and that retreat is accompanied by landslides, laying havocs with reference points. The edge of glaciers would be mostly moving up, toward Switzerland, and the landslides are moving down, toward Italy.

The redrawn border may move by as much as 100 meters in some spots, but no communities will be affected as this is an area of high altitude, remote and cold. The most famous location in the affected area is the picturesque, 4,478 meter-high Matterhorn (by its Swiss name), or Cervino (as it is known in Italy).

Links of interest:

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