I’ve never really gotten interested in “geocaching”, the recreational sport of tracking down of hidden containers or cache by geographic location. But I’ve just found out about a related variant that meshes nicely with my interest in geology: EarthCache. As with a geocache, you go to a location based on geographical coordinates, but the reward is not tracking down a box or trinket, but seeing an area with interesting or unique geological features. Earthcaches are located around the world, with roughly half of them are in the United States. There’s a searchable index that lets you locate Earthcaches by country, state, and type (fossil site, erosional feature, igneous feature, etc.). Quick tip: for sites in America, choose “USA” for the country rather than “United States”’; the latter only has a few sites listed. Once you locate a site of interest, clicking on the link will take you to the information page for the site at Geocaching.com:
The information page generally includes a description of what makes the site interesting geologically, often with diagrams, photos and references. For full site coordinate data, you’ll need to register at the site and agree to a standard disclaimer, i.e. they’re not responsible for anything bad that might happen. Once registered, the coordinates will show up at the top, along with the option to download a LOC waypoint file. GPX file downloads require a paid membership, but LOC files can be opened using the free program EasyGPS and then either directly uploaded to your GPS or saved as a GPX file.
If you want to keep track of the sites you’ve visited, and get official recording of your visit at the Geocaching site, the info page will list off some required information, like photos, a general description, and several questions to answer about the geology. You can also leave comments about your visit, or read those of others before you go. And if you have a site that you think would make a good EarthCache, you can submit it. This is a great resource for both geology nuts and educators.
The Eruptions blog links to reports of significant earthquake activity (6 quakes of 4.5+ on the Richter scale in the past week), radon outgassing, hot gas and hot water coming from wells, and more, from a volcanic area about 240 km WNW of Medina, Saudi Arabia, and 50 km from the Red Sea. USGS KML files showing worldwide earthquakes over the past week are available here. Here’s a Google Earth view of the area, with the earthquakes plotted as yellow dots:
The darker areas are basalt flows from earlier eruptions, and the red dots/blogs are likely cinder cones. The last eruption in this area took place about a thousand years ago.
As the Eruptions blog indicates, the data still isn’t conclusive, but some of these signs might be precursors of a volcanic eruption; Saudi Arabian authorities are evacuating people in a 40-km radius around the zone in question.
The OneGeology website gives its mission as:
Make web-accessible the best available geological map data worldwide at a scale of about 1: 1 million, as a geological survey contribution to the International Year of Planet Earth.
While the official launch of the site is scheduled to coincide with the International Geological Conference in Oslo, August 6-14, the mapping portal site is already partially functional, although a few bugs and quirks still exist. It currently works with Internet Explorer 6/7, and Firefox 2, but not Firefox 3 (hope this changes soon). And while the goal is to have data for the whole world at a 1:1,000,000 scale, data for significant areas of the world are currently not available at that scale; for example, the US data is at the 1:5M scale. A partial list of the WMS data available and its scale is on this page.
Continue reading ‘Online 1:1M Geology Maps At The OneGeology Portal’
The National Geophysical Data Center has downloadable bathymetric and fishing maps for most of the US ocean coastline (not intended for navigation purposes, though). Map catalogs are broken down by geographic region, and maps are available in both small PDF preview format and large format downloads in either PDF or TIF format (the latter in gz compression, which will require an unzipping program like WinZip or ZipGenius). If you need the PDF maps in a editable graphic format, you can use a program like PDFCreator to “print” the PDF maps in full-resolution TIFF, JPG, or PNG formats. Maps are also not georeferenced (not GeoTiffs or GeoPDFs); I hope to cover some basic georeferencing options soon.
The full sets of data available from the NGDC include more bathymetric and relief data, geology/geophysical data, and earthquake/volcano data.
Living in the dry climate of the US Southwest, I’ve always found springs fascinating. For someone who grew up in the suburbs, water flowing continuously out of the ground with no pipeline or spigot somehow seems unnatural. But even more bizarre is hot water flowing out of the ground. NOAA’s National Geophysical Data Center has an online queryable map of Thermal Springs of the United States:
“Thermal” doesn’t necessarily mean “hot”; the orange dots indicate water temperatures of 20C – 50C, while red dots run from 50C all the way up to boiling. But in all these cases, the water from the spring is elevated above what comes out of other nearby springs that aren’t heated geothermally. Most are concentrated in the more geologically-active western states, but with a few exceptions (most notably, the ones in Arkansas that include Hot Springs National Park). Using the “Identify” control to click on a thermal spring brings up its lat/long, water temperature, USGS quad, and more info.
The BBC has an article on the release of the first worldwide map of magnetic anomalies, deviations in the earth’s magnetic field due to effects from magnetized crustal rocks. Nice views of the magnetic striping on either side of the Mid-Atlantic Ridge resulting from ocean-floor spreading (the driver of continental drift) and prehistoric reverses in the direction of the earth’s magnetic field:
From the Commission for the Geological Map of the World, which has links to this and other small-scale world geology maps for sale; the BBC article has a link to a free high-resolution PDF map of the magnetic anomaly map.
Portland State University’s Glaciers Online site has maps, photos and data for glaciers of the American West. Contents include:
- Shapefiles of glaciers and glaciated regions
- PDF maps from the 1975 government report “Mountain Glaciers Of The Northern Hemisphere”
- Glacier photos by location and time, highlighting the gradual retreat of glaciers with global warming
- A queryable online map
- Bibliography and links to more general info about glaciers (did you know there’s a glacier in Nevada?!)
Other mapping sites seem to be doing an Earth Day related post, so I’ll move this one up a bit. Energy production from the heat of the earth (geothermal energy) generates no carbon dioxide emissions that contribute to global warming, and could produce as much as 100,000 megawatts in the US alone by the year 2050. Here are some websites with geographic geothermal data, both maps and downloadable data.
Continue reading ‘Geothermal Resources Data’
