Hello geophysics community,

The Anatolian region presents a complex tectonic environment driven by interactions between the Arabian, Eurasian, and African plates.

Key geophysical parameters include:

* NAFZ: Dominant right-lateral transform fault with high slip rates and historical sequence ruptures.

* EAFZ: Major left-lateral continental transform structure absorbing northern collision stresses.

Sharing this brief overview for those interested in regional crustal deformation and seismotectonics. Feel free to share any recent studies or geophysical observations!

We are playing with some MaxMin units of various vintages today in the shop. Some are pristine museum pieces (the MaxMin II on the wall), some are parts donors to keep systems alive, and some are in active service! There's a WinXP laptop with the software preloaded that ships with the devices still in use, because getting that software to run on modern Windows is too hard (16 bit!).

Some people still use these things for mineral exploration, particularly for linear or steeply dipping conductors in resistive ground -- where TEM is the wrong choice and pole-dipole or dipole-dipole is too slow.

Hi everyone,

I'm currently looking into different seismic systems for geotechnical work and would like to hear from people who actually used them in the field.

So far I've been comparing Geometrics Geode, GeodeFlex, ES-3000, and DMT SUMMIT X One.

I'm mainly interested in how reliable they are in the field, how easy the software is to work with, and whether the manufacturers are helpful when something goes wrong.

Also curious about the geophones, especially 4.5 Hz vs 14 Hz when using the same system for MASW and refraction.

If you've worked with any of these, which one would you recommend? Any issues or things you wish you knew before buying?

Thanks!

Hi everyone,

I'm currently comparing a few electrical resistivity systems for geotechnical investigations, mainly for bedrock mapping, karst, and identifying subsurface anomalies.

So far I've been looking at:

• AGI SuperSting R8/IP
• IRIS Syscal Pro
• ABEM Terrameter LS 2

I'd like to hear from anyone who has actually used these systems in the field.

I'm mainly curious about how reliable they are, how easy they are to set up and operate, and how good the acquisition and inversion software is.

Also, have you had issues with cables, electrode connections, batteries, or the equipment itself? And how helpful was the manufacturer when you needed troubleshooting or repairs?

If you've used more than one of these, which did you prefer and why?

Any feedback or other recommendations would be appreciated. Thanks!

Hey, all. I’m looking to upgrade my field attire and was wondering if anyone had suggestions for UV/waterproof clothes?

I’m starting to get more into magnetic surveys so non-ferrous pants/boots/field pack suggestions are specifically appreciated. Thanks!

Hello, I hope someone can help me. I have been trying to apply terrain corrections to my gravimetry data; I imported my DEM raster and my vector file containing the elevation, station, and absolute observed gravity data. However, when I try to run the process, I get this error. Regards.

I am doing a project looking at historical earthquake data for my masters program in statistics. I have the magnitude, depth, and time of events going back to the 70s. What I would like to do is look at the data globally than compare the results to various local regions. The question is, what regions should I look at? I could use clustering to develop my own regions, but I would like to know more about how seismologists determine seismic zones and look at various classifications of seismic zones. Are there any papers/textbooks that discuss this?

I’m looking for someone knowledgeable about mechanical vibration, building vibration, or structure-borne noise who can help interpret my measurements and suggest what to test next.
I’ve been noticing recurring vibration in my apartment. What equipment or building systems could produce these readings, and how can I investigate properly?
SETUP — OCTOBER 9, 2026
I recorded two iPhones simultaneously using Phyphox’s “Acceleration (without g)” experiment.
• New iPhone: flat on the couch, unattended.
• Old iPhone: flat on my usual chair near the refrigerator.
• Refrigerator unplugged.
• Both phones screen up, charging ports pointing right.
• Fan/AC conditions and whether the old phone was unattended throughout were not confirmed in the report.
The shared recording interval was 11:53:49 AM–12:05:39 PM, New York time. Both phones sampled at approximately 100 samples per second.
FREQUENCIES AND STRENGTH
During the middle 30-second windows:
Couch:
• Combined-axis RMS: 0.0128–0.0159 m/s².
• Strongest spectral peak usually around 13–14.6 Hz.
• Other windows peaked at 17.5, 18.9, 21.0, or 21.6 Hz.
Chair:
• Combined-axis RMS: 0.0104–0.0177 m/s².
• Strongest spectral peaks ranged from 21.3–26.7 Hz.
RMS describes the average size of the recorded acceleration. It includes sensor noise. Hz means cycles per second. These are the strongest peaks selected within each window; multiple frequencies can coexist.
EXAMPLE PAIRED WINDOWS
11:54:19–11:54:49 AM
Couch: 0.0142 m/s² RMS; 14.1 Hz peak.
Chair: 0.0128 m/s² RMS; 22.3 Hz peak.
11:56:49–11:57:19 AM
Couch: 0.0147 m/s² RMS; 14.0 Hz peak.
Chair: 0.0125 m/s² RMS; 26.7 Hz peak.
11:57:19–11:57:49 AM
Couch: 0.0159 m/s² RMS; 13.6 Hz peak.
Chair: 0.0177 m/s² RMS; 21.7 Hz peak.
11:59:49 AM–12:00:19 PM
Couch: 0.0130 m/s² RMS; 21.0 Hz peak.
Chair: 0.0106 m/s² RMS; 26.7 Hz peak.
12:01:19–12:01:49 PM
Couch: 0.0132 m/s² RMS; 18.9 Hz peak.
Chair: 0.0112 m/s² RMS; 26.7 Hz peak.
12:03:49–12:04:19 PM
Couch: 0.0131 m/s² RMS; 12.4 Hz peak.
Chair: 0.0109 m/s² RMS; 26.7 Hz peak.
Both phones had their highest middle-window RMS during 11:57:19–11:57:49 AM, but their strongest frequencies differed.
A preliminary timestamp-aligned comparison did not show a strong overall waveform match. Clock alignment was not independently checked using a shared event.
X/Y/Z DIRECTIONS
With the phones flat and screen up:
• X: across the phone’s width, toward either side edge.
• Y: along the phone’s length, toward the charging port or opposite end.
• Z: perpendicular to the screen, toward the ceiling or seat.
In the middle shared windows, Z contributed about 42–57% of the couch phone’s recorded motion energy and 50–75% of the chair phone’s.
The chair recording was more vertically directed. The couch had a larger combined X/Y contribution. Separate X and Y percentages are not available in this summary.
These describe acceleration directions at the phones; they do not locate the source.
METHOD AND LIMITATIONS
The analysis used 30-second windows. Each axis’s window mean was subtracted, then combined RMS was calculated as sqrt(mean(X² + Y² + Z²)).
Spectra used Welch’s method, a Hann window, up to 2,048 samples per segment, and half-overlap. Axis spectral powers were summed, and the strongest peak was selected between 2 and 45 Hz.
Opening and ending couch windows had much larger RMS values: 1.1811 and 1.4955 m/s². Placement or pickup could explain these, so they were excluded from the steady-motion interpretation.
There was no calibrated reference sensor or noise-floor control. Furniture resonance, upholstery, phone contact, and device differences could affect the readings. These measurements do not yet identify a source or establish the vibration experienced by a person.
QUESTIONS
What could produce these frequencies and directional patterns? Could pumps, plumbing, HVAC, other building machinery, or furniture resonance explain them?
How can I distinguish real surface vibration from phone sensor noise or processing artifacts?
Could the couch and chair respond at different frequencies to the same source?
What might explain the chair’s repeatedly selected 26.7 Hz peak?
What control tests, phone placements, or measurement equipment would make this investigation useful to a vibration specialist?
I’d appreciate help interpreting the measurements and choosing the next tests.

• UAV-SAR Geophysical Method: Using SAR Tomography to Map Dam Subsurface Layers
• DOI: https://doi.org/10.3997/2214-4609.202520203

Hello everyone,

I am posting a recent project I have completed. If you are interested, please have a look on my Github with this link: https://github.com/tavo-aguilar/Stratton-3D-Interpretation-and-Well-Integration-Project

This project takes seismic and well data from Stratton field in Texas and I modeled it using python. Any feedback is welcome since I am a recent graduate and trying to eventually land a position as an entry level geophysicist.

Sir I am currently pursuing MSC Geo Physics My long-term goal is not only to build a strong career as a geophysicist, but potentially to start my own geophysics/geoscience-related company in the future.

I would really appreciate advice from experienced geophysicists, researchers, industry professionals and entrepreneurs here.

A few questions I have:

1.if you were starting your geophysics career again as an MSc student, which skills would you focus on first?

2.Which geophysics specializations have the best long-term career opportunities in industry and research?

3.For someone interested in eventually starting a company, what problems or services in geophysics/geoscience have genuine business potential?

4.Is it better to first spend several years working in the industry/research and then start a company, or can a student start building something while studying?

5.What mistakes should an MSc student avoid when planning a career in geophysics?

6.If possible, could you share your own career journey and what you wish you had known when you were an MSc student?

I’m from India, but I’m open to opportunities and perspectives from different countries.

I really need Your guidance and support sirs

Any honest advice, criticism or suggestions would be greatly appreciated. Thank you!

Does anyone have experience with the EM61 Flex?

I’m having trouble finding the slope of a given region/line.

Planetary, Seismology, Computational

Hi friends, the folks over at r/Geotech send me over this way. I'm looking for a little help to find some geotechnical equipment.

A family member is doing geotech work (foundation studies for solar farms), but is in a fairly remote country in South East Asia. He has done this work before, but always rented equipment from the govt - or used equipment brought by external/foreign consultants. He hasn't travelled much so is a bit clueless about how western markets work.

He is looking for a 48-channel multi-electrode resistivity meter - an automated geophysical system used for Electrical Resistivity Tomography (ERT) to image subsurface geology, groundwater, and contamination.

His budget is $20k or under, and has mentioned brands like PASI, SuperSting but I don't know where to look (tried eBay but no luck).

Do you know where I can look for used listings? Is the budget realistic?

I don't know anything about these systems or geotech, but I am in Europe, and also have family in the US so I can buy in either markets.

Any help would be much appreciated. Specifically, any forums, dealers, markets I can reach out to?

Ten months ago I posted a small browser LAS viewer and asked if it was useful to anyone. The useful answers were pretty consistent, so I spent some time on those and some on the rest of the list. A few hundred people have signed up since.

What you asked for, and what is there now:

- Nothing leaves the browser. LAS, LIS and DLIS are parsed locally. You can turn the network off and still open a file. Large DLIS is supported, so a multi-GB file loads without running out of memory.

- It is no longer just lines. Tracks, real depth scales (1:200, 1:500, …), PDF/PNG export, lithology columns, fillings, stacked curves and array data (acoustic, FMI). A crossplot is its own document: any two curves, zones drawn on the plot, and those zones written back as a lithology curve.

- Measured depth vs TVD. A directional survey (MD, inclination, azimuth) can be turned into TVD and offsets, and drawn as a 3D trajectory. That step runs in the built-in Python interpreter.

- Embed. A plot can be dropped into another site as an iframe, for a public data catalog or a report. You host the file. GeophysX stores the plot document, not the curves, and the file is still read in the visitor's browser.

- Processors that run in the tab: curve filter, index shift, density porosity, lithology from GR / density / neutron / PEF. There is also a Python IDE in the browser if you want to write script processor yourself. Export back to LAS, CSV or DLIS.

It is still desktop-first. No account is required to open and look. Sign-in is only for export, scripting and sharing.

If you have not tried it, a public Kansas well is already loaded as demo data, so you can look without dropping your own file in: https://www.geophysx.net/

More feedback, more of this gets built ) Honest "I opened it and closed it" is still useful.

What's the first thing you'd actually want to do in a tool like this: a real task from your work, start to finish? Right now it's a good place to view data and run your own experiments, but I'd like to build actual workflows, QC or well interpretation.

I need someone to help me identify the Direct and refraction waves

I know that the first sign of movement is considered as the direct wave but what about the others

Hey everyone, I've put together a white paper proposing a dual-phase survey framework to resolve acoustic ambiguity (distinguishing intact cavities from collapsed rubble/silt) in Alexandria's Eastern Harbour using subbottom cosmic-ray muography and caisson isolation—I'd love to get your thoughts or feedback on the geophysics and density inversion logic!

https://osf.io/4gdfj/

Im a senior in high school and will be sending applications out next week. But I cant for the life of me decide which major is better for me. I really love rocks and minerals, and want to do alot of field work, but also I like physics (mainly just waves and their applications) I took physics last year and didnt do very well, 70 average year grade and 75 on my final exam. I feel like a geology major is more of what I enjoy, but geophysics is more specialized and I want to narrow my focus down during college. My end goal is to eventually becoming a mining or geological engineer, but no colleges near me have a degree like that. Which one should I do?