Blog | Advanced Geosciences Inc

Equatorial Array: Electrical Resistivity Methods, Part 6

Posted by Sean on Jun 03, 2019


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.


If you want to check out the previous arrays we’ve discussed, here are links to those posts:  

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The AGI Blog - Electrical Resistivity Methods, Part 6: The Equatorial Array

How To Do Small-Scale Electrical Resistivity Imaging Lab Tests

Posted by Sean on May 13, 2019


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.


With tools like the SwitchBox Grid®, researchers can create and use DIY electrode cables that are more manageable for small-scale in-class demonstrations. (Psst...we've snuck in a video explaining the SwitchBox Grid® at the end...

AGI Blog - How to perform Resistivity Surveys at Scale

2019 Karst and Cave Meeting Calendar

Posted by Sean on May 03, 2019


If you’re anything like us, cave/karst conferences tend to sneak up on you. You spend a week in May attending Hypogea in Bulgaria, and before you know it, it’s October and you’re in the USA attending the National Cave and Karst Management Symposium.


So to help you keep track, we’ve put together this definitive list of cave and karst meetings happening in 2019. Enjoy!


AGI Blog - 2019 Karst and Cave Meeting Calendar

Customer Spotlight: USGS | Using Resistivity to Map Permafrost Erosion on the Alaskan Coast

Posted by Sean on May 01, 2019


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.


In September...

AGI Blog - Mapping Permafrost Erosion on Alaskan Coast

April 2019 AMA Webinar Hosted by Eduardo Rodrigues (Spanish)

Posted by Sean on Apr 17, 2019


This Spanish-speaking "Ask Me Anything" webinar was hosted by Eduardo Rodrigues on 4.2.2019. Eduardo is a highly-experienced Geophysicist at our Madrid office.


There were several topics covered—all of which were generated by questions from the audience. You can link to each question using the chapters function in the video below. Want to take part in our next webinar? Sign up for webinar alerts from us so that you get an email the next time we host one for your country/time zone.


AGI Blog - April AMA Webinar hosted by Eduardo Rodrigues

Quick Tip: Depth of Investigation for ERI Surveys

Posted by Sean on Apr 15, 2019


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.  


What is depth dependent on in ERI?

First of all, depth of investigation will depend on the largest array span you use during your survey. Array span shouldn’t be confused with survey line length. It’s a common misconception that longer survey lines=more depth or that roll-along=more...

AGI Blog - Depth of Survey in ERI

Quick Tips: Electrode Preparation and Removal

Posted by Sean on Apr 10, 2019

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!


Tip 1: Getting the stakes installed correctly will save you troubleshooting...

AGI Blog: Quick Tips for Using Electrodes

Typical Ranges of Resistivities for Common Materials

Posted by Sean on Mar 28, 2019


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.


AGI Blog - Typical Resistivity Values of Common Materials

Single-Channel vs Multiple-Channel Systems

Posted by Sean on Mar 26, 2019

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.


Of course, there are a few more bells and whistles that a multi-channel system offers, but the key difference is how much faster it is when compared to a single-channel. That’s what we’ll focus on in this...

AGI Blog - Single Channel Systems vs Multi Channel Systems

How will weather conditions affect your geophysical surveys?

Posted by Sean on Mar 21, 2019

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.  


We’ll be discussing how weather affects your survey in general. If you want to learn more about how our...

AGI Blog - How does the weather affect your geophysical survey?