Mobile apps in the Field

The Field, as in the Internet. The capital letter indicates respect, admiration and so on. So for all of you field geologists, who happen to like mud on your boots and sunburns (who doesn’t!) you may find this post useful.

There are many portable geology apps, both in Android as well as in iPhone. When we go mapping on the field we like to carry loads of instruments: Compass, hammer, measure tape, HCl, sample bags, etc. Using a smartphone has at least alliviated the need to carry a camera for quick observations, but what if it could also improve on our compass and notebook? I read about this kind of apps on other blogs like Androgeoid or Un geólogo en apuros.

Geohammer and mobiles
This feels like the right array of weapons.

So, I went ahead and selected three Android apps and tested them in the field: Rocklogger, Fieldmove Clino and to a lesser extent Theodolite (as it offers less geology-related content). For you Apple fans, try Fieldmove Clino for free via iTunes.

Here is what I think about each of them:

  1. Rocklogger has a harsh interface at first, but it’s great and simple. You can easily log measurements of different types and plot them on a map. Paid version offers stereonet or KML export (for use with your favourite Geographic Information System).
  2. Fieldmove Clino has a cleaner interface, offers logging, plotting on map and even photo geotagging. Its core features are similar, with paid versions supplying stereonet and KML export.
  3. Theodolite acts as a clinometer of sorts. For the ones that do not want too complicated apps: Vertical is 0º so you’ll want to substract 90º to get the dip of your plane. No logging so you’ll have to input the data into a notebook or another app.
A) Rocklogger. B) Fieldmove Clino. C) Theodolite.
A) Rocklogger. B) Fieldmove Clino. C) Theodolite.

Be aware that Rocklogger gives dip direction as north-based azimuth and Fieldmove Clino in its compass mode gives East – West declination, so for the two images above the dip direction is approx. N 220º.

I feel the two first programs are similar, with Rocklogger requiring less clicks and dragging to log, so despite the nicer interface of Fieldmove Clino it would prove better in a long traverse.

Testing them against an old Silva compass yielded very close results, so I like the accuracy of the apps: The dip angle was the same for the three apps and the compass; the dip direction gave the same results for both Rocklogger and Fieldmove Clino and was close enough to what I measured analogically.

Here you can see the aspect of the log record in both apps, which are pretty useful to know at a glance the main directions of your lithology:

The logs: Rocklogger on the left and Fieldmove Clino on the right.
The logs: Rocklogger on the left and Fieldmove Clino on the right.

All in all, I see this kind of application as a very good partner in the field for the mapping geologist. It makes measurements take less time, and more measurements mean the small instrumental error can be mitigated (but always make sure to check with more analogical means, just in case).

Give them a try, you’ll not regret it!

The mineralogist’s web companion

If you ever wanted to inform yourself about mineral structures, composition or properties, you can always search on Google (or the search engine of your choice); this will surely lead you to the Wikipedia page on that mineral. As good as the online encyclopedia is, I’d recommend also checking out the two links you’ll have below it: ( and the Mineralogy Database (

These two webpages offer a detailed description of each and every mineral there is, including X-Ray diffraction data, crystalline structure, chemical properties, and good bibliographical references if you want to dig up the history of said mineral. So, for example, if we wanted to know more about pyrite (fool’s gold) we could search it, and click on the first three links we come across: Wikipedia, Mindat and Webmineral.

Mineral databases surrounding a pyrite crystal
The three main mineral databases

Each offers good value in its own: I feel like Wikipedia is very good at giving a general overlook on the mineral, its distribution and uses, while Mindat and Webmineral are very good at giving detailed information and references. The two latter choices also have a nifty search engine where you can specify elements of the periodic table for searches on chemical composition of minerals.

Another awesome feature of the alternatives to Wikipedia are the 3D models detailing crystalline structure or atom distribution. You’ll need Java installed, but they are powerful tools, as they let you drag the models to rotate the view.

3D models of pyrite: A) Crystalline structure. B) Forms.

All in all, you’ll end up using these three among many other databases, but these three are the bread and butter of the mineralogist’s day. Go check them out! Seeing your favourite mineral in glorious 3D is something to look forward to.

Become a virtual seismologist today!

This may sound as an infomercial, but there will not be any black & white videos of people failing at things. Today I want to talk about the Virtual Earthquake Lab of the Virtual Courseware Project.

Click on this link to access the virtual laboratory. Be sure to enable popups on your browser and to have Java installed, and click on the buttons to the right. If you go from top to bottom of the page you’ll get an idea of how seismologists read seismograms, calculate travel times, amplitude of the waves and you’ll also get to find the epicenter and magnitude of historical earthquakes.

I feel like the real deal!
My take on the 1994 Northridge earthquake.

There is a lot of explaining in each of the exercises and the user interface is very intuitive, so you’ll get the hold of it in no time. You can get through all there is in the virtual laboratory in around one hour; after that, you’ll be tested and you’ll earn a cool certificate, qualifying you as an earthquake researcher of sorts!

I feel pretty proud of this.
Certificate of completion, in all its 2001 glory.

I first did this exercise on 2006, but I must say it hasn’t lost charm and entertainment and is worth a try. If you are running an old PC, or if you hate Java, you can access an older version of the virtual laboratory here.