Electrical Resistivity Surveys mostly happen outdoors. Of course, you can perform small-scale tests indoors, but most clients aren’t going to give you such a comfortable project. So you’ll need to make your way outdoors into the heart of mother nature. And as such, you’ll be sharing your space with all manner of wildlife.

Some animals will shy away if they notice you working around their habitat. Others can be more curious—or attracted to some aspects of the survey.

Welcome back to our series detailing the different electrode arrays that you may come across in your work. This is the seventh article in our series exploring 11 electrode arrays and methods. We’ve covered some of the standard arrays that will cover most of your bases. In the last post, we’ve started talking about some lesser known arrays. Today, we’re discussing another non-standard electrode array—the Square Array.

Many moons ago we wrote a series of blog posts detailing the standard array types that you’re most likely to use in your work (links below). Now we’re back to finish off the series with the remaining 6 arrays that aren’t commonly used. And since we’re in the middle of this blog series, why not discuss the Equatorial Array? Get it? Because “equatorial” sounds like “equator”. Ok, bad jokes aside, let’s get on with it.

In the academic world, small-scale resistivity tests come up a lot. Often, researchers need to demonstrate the theory in action. And even more often, they don’t have the space to set up a standard cable of electrodes.

The USGS has done stellar work to better understand the erosion of shorelines on the U.S. Arctic coast. Two teams of scientists traveled to the very actively eroding Barter Island to collect data. Both teams observed erosion and associated shoreline loss through various means, which you can read about in full here.

This being the AGI blog though, we want to focus on the Electrical Resistivity Tomography (ERT) part of the project.

You can’t talk about Electrical Resistivity Imaging (ERI) surveys without eventually talking about depth. Aside from resolution, depth of investigation is one of the first talking points our customers want to discuss when considering ERI surveys.  

We here at AGI are big advocates of saving time. Seriously, if time is money—then we’re serious penny pinchers. That said, we’re always looking to pass on time-saving tips to you! Today we’re showing you a couple of quick tips that can save you a couple of minutes on the field. Particularly, these tips are focused on electrode preparation and removal. You may scoff at saving a few minutes, but here in the Texas sun—a few minutes is the difference between a suntan and sunburn!

Electrical Resistivity Imaging (ERI) is a fantastic geophysical method for subsurface exploration and delineation (it certainly is our favorite!). In this article, we want to focus more on the “geo” part of geophysics and take a look at some resistivity values for common materials.

You see, ERI works best when you have a good knowledge of the geology of your survey area. In fact, when we’re helping new customers design their survey, or helping someone in the field—the geology of the area is one of our first questions.

Our customers often want to get the most out of our equipment while sticking to their budget. As such, many will opt for a cheaper single-channel system instead of a multiple-channel system. When customers are weighing the options, we often get the question “What’s the difference between the two?”.

The simple answer? Speed.

In the field, you’ll often find out that Mother Nature isn’t concerned with your project timelines. But whether there’s rain or shine, you’re expected to meet your deadlines. As such, we often get questions from our customers on what kind of weather is reasonable to work in. So in this post, we’ll be listing the weather conditions that pose no problems, conditions that will slow you down, and conditions that will halt your survey completely.