Search found 935 matches

by geophix
Fri Feb 12, 2021 6:58 pm
Forum: General Geophysics and Geoscience
Topic: Magma as a generator of plasma and thermonuclear fusion in the bowels of the Earth
Replies: 5
Views: 235

Re: Magma as a generator of plasma and thermonuclear fusion in the bowels of the Earth

You certainly got a lot of new ideas. I will certainly read them when I got time. Currently I am so busy, but good to know there are some interesting ideas out there. I used to think seismology is almost dead: we already got the general idea, we just need to fill in the details. :lol:
by geophix
Tue Feb 02, 2021 3:22 pm
Forum: Near Surface Geophysics
Topic: Good devices to detect Void/graves
Replies: 8
Views: 455

Re: Good devices to detect Void/graves

You might be able to find a 2nd hand ground penetrating radar with that price range.
by geophix
Fri Jan 15, 2021 4:47 pm
Forum: Near Surface Geophysics
Topic: Archaeologists Are Just Beginning to Unearth the Mummies and Secrets of Saqqara
Replies: 2
Views: 346

Re: Archaeologists Are Just Beginning to Unearth the Mummies and Secrets of Saqqara

Anyone has Netflix subscription to share the thoughts about the documentary "Secrets of the Saqqara Tomb"?
by geophix
Sat Jan 02, 2021 3:29 pm
Forum: General Geophysics and Geoscience
Topic: Nature and Energy of Earthquakes or Seismology for Dummies
Replies: 17
Views: 1195

Re: Nature and Energy of Earthquakes or Seismology for Dummies

Seismologists, like brave liars, lied, and continue to lie. You want to eat, so they lie! Earthquakes are impossible to predict! And to get a piece of the pie, you just need to declare to the whole earthly world that in 100 years, somewhere there will be an earthquake. This is how everyone can make...
by geophix
Sat Jan 02, 2021 3:19 pm
Forum: General Geophysics and Geoscience
Topic: Water well in limestone enhance production?
Replies: 3
Views: 268

Re: Water well in limestone enhance production?

I guess high resistivity zones correspond to fresh water bearing zones? And interestingly these zones have relative "flat" caliper readings. Maybe these zones are plugged?
by geophix
Fri Jan 01, 2021 6:05 pm
Forum: General Geophysics and Geoscience
Topic: Water well in limestone enhance production?
Replies: 3
Views: 268

Re: Water well in limestone enhance production?

I have done some geophysical borehole loggings before, but I am curious how you define plugging the water well. I guess if you plug the well only at the bottom, then you can still do the logging?
by geophix
Fri Jan 01, 2021 6:02 pm
Forum: General Geophysics and Geoscience
Topic: Nature and Energy of Earthquakes or Seismology for Dummies
Replies: 17
Views: 1195

Re: Nature and Energy of Earthquakes or Seismology for Dummies

serguei58 wrote:
Fri Jan 01, 2021 4:56 pm
Remember, earthquake prediction is impossible !!!
It depends on the definition of prediction. Long term earthquake predictions are apparently much better than short term predictions.
by geophix
Fri Jan 01, 2021 5:59 pm
Forum: Near Surface Geophysics
Topic: Locating a man made tunnel
Replies: 28
Views: 11840

Re: Locating a man made tunnel

99thpercentile wrote:
Fri Jan 01, 2021 4:20 pm
gopal123


Why did you retype my previous answer in your own words?
It looks like a spammer.
by geophix
Wed Nov 18, 2020 10:30 am
Forum: Near Surface Geophysics
Topic: Locating a man made tunnel
Replies: 28
Views: 11840

Re: Locating a man made tunnel

How deep was the tunnel? How big was it?
by geophix
Sun Oct 11, 2020 1:05 pm
Forum: Near Surface Geophysics
Topic: 2D Cemetery mapping with GPR
Replies: 3
Views: 2122

Re: 2D Cemetery mapping with GPR

The link doesn't work -> file not found.
by geophix
Wed Oct 07, 2020 6:17 pm
Forum: Near Surface Geophysics
Topic: UgCS GeoHammer webinar
Replies: 2
Views: 954

Re: UgCS GeoHammer webinar

:thumbup:
by geophix
Wed Oct 07, 2020 6:15 pm
Forum: Near Surface Geophysics
Topic: 10 vs 3.5 kHz SBP system for shallow water
Replies: 2
Views: 855

Re: 10 vs 3.5 kHz SBP system for shallow water

10KHz gives you better resolution and 3.5KHz gives you better penetration depth. I prefer 10Khz since clayey and silt sediments are more friendly than sands for penetration.
by geophix
Sat Sep 12, 2020 12:07 pm
Forum: Near Surface Geophysics
Topic: a strange GPR anomaly
Replies: 4
Views: 1126

Re: a strange GPR anomaly

I took another look at the file. Now I realize it might be an underground wall with a slope. I think it's safe to say the mystery is mostly solved.
by geophix
Sat Sep 12, 2020 10:12 am
Forum: Near Surface Geophysics
Topic: Locating a man made tunnel
Replies: 28
Views: 11840

Re: Locating a man made tunnel

Kknq, please see a void model and its gpr data simulation below. You can see there are apparent different responses between the two sides and the middle of the void. When the void spacing (depth wise) is small, you can easily get the "ringing" effect as shown at the two sides due waves bouncing betw...
by geophix
Wed Sep 09, 2020 6:55 pm
Forum: Near Surface Geophysics
Topic: a strange GPR anomaly
Replies: 4
Views: 1126

Re: a strange GPR anomaly

I still tend to believe it might be some kind of diffraction from something close to the ground surface, but it doesn't look like any diffractions I usually see. I haven't really think it through.
by geophix
Tue Sep 08, 2020 5:47 pm
Forum: Near Surface Geophysics
Topic: a strange GPR anomaly
Replies: 4
Views: 1126

a strange GPR anomaly

This is a GPR profile I collected close to a storm drain catch basin. The catch basin is at the ground surface between 13 to 16 ft in this profile. The strong "slope" signals to its left look very unusual. 270 MHz antenna.
GPR strange data.png
by geophix
Tue Sep 08, 2020 3:35 pm
Forum: Near Surface Geophysics
Topic: Guess what's in the GPR profile
Replies: 11
Views: 3445

Re: Guess what's in the GPR profile

Shielded or not, aboveground objects can show up in GPR data. GPR waves will be bounced back to the ground surface anyway -- they will keep travelling upward and then coming back down if there are aboveground objects.
by geophix
Tue Sep 08, 2020 3:28 pm
Forum: Near Surface Geophysics
Topic: Locating a man made tunnel
Replies: 28
Views: 11840

Re: Locating a man made tunnel

To be honest, the anomalies do look like voids. I just realize that your tunnel might not be in a regular shape. I mean the top and walls of the tunnel might not be smooth at all. The GPR signals will bounce around inside the tunnel and show the signatures like the anomalies shown in your GPR profil...
by geophix
Mon Sep 07, 2020 1:31 pm
Forum: Near Surface Geophysics
Topic: Locating a man made tunnel
Replies: 28
Views: 11840

Re: Locating a man made tunnel

At least you can see some anomalies. If the anomalies were caused by a tunnel, the tunnel might have collapsed. I think the more important question is, how large the area have you scanned. If you see this kind of anomalies everywhere, it's probably not a tunnel. If it's the only anomaly area you see...
by geophix
Sat Sep 05, 2020 4:56 pm
Forum: General Geophysics and Geoscience
Topic: wavefront vs wavefield
Replies: 2
Views: 609

Re: wavefront vs wavefield

If you drop a rock into a lake, the whole surface of the water becomes the wavefield as the water wave propagates. Each circle around the center where the wave starts is a wavefront. A wavefront is an interface (a straight line, a plane, a circle (as in this case)) or a ball, etc in the wavefield, o...