Benchmarks Struck By Lightning

[+Team Gecko]

After I shared this photo of Ysidro No 1 (DX4949) on top of a seldom visited desert peak in northeastern San Diego County, Patty Winter suggested I post it and launch a Forum thread on the topic of lighting strikes and how they affect benchmarks.

 

 

I am interested to discover if any other BM loggers have seen this kind of feature before. Anyone care to offer another interpretation of what may have caused the hole in this benchmark disk?

-Gecko Dad

[+Kewaneh & Shark]

I would imagine that it could be a lightning strike that would cause damage like that. I haven't seen many things that have been struck by lightning, let alone a brass cap, so I have nothing to compare it to. Benchmarks, and triangulation stations & their reference monuments, are commonly set in high locations. Exposed metal on a high peak would be a good target for an electrical storm.

 

The damage could be man-made as well, although most man-made damage done after the mark is set, is in the form of scrapes and dents, not chipped holes. (Or melted or burned holes, for that matter.) Or, it could be a flaw in the brass too.

 

The only person who would know for sure is the person who actually did the damage, be that man, or God, or Mother Nature.

 

- Kewaneh

[WVski]

Kinda looks like a bullet hole to me.

 

I cannot see it in detail though, i cant tell if it is burned around the hole or not.

 

Would it be possible for a bullet to hit this mark in its location?

[+GEO*Trailblazer 1]

I have seen where lightning has hit metal objects in the ground.

There is usually more severe damge than I can see here.

 

Just for referenc look at a lightning struck tree.

I have seen cement also disintigrated where the initial hit was located.

 

In fact I watched lightning hit the curb right in front of me and an explosion like a bomb was seen and the curb was completely destroyed.

 

Just my .02

[Photobuff]

This is a wild guess, but a large rock isn't very conductive. The current flow would have been mostly over the surface, and it's entirely possible that the damage to the mark would have been small. Aircraft get hit by lightning quite often, and I believe the damage is similar. OTOH, if there's a good path to conductive ground, the localized current flow will be huge, vaporizing anything along the path. Current will take the path of least resistance, and if a piece of metal can take that current to ground, that's the path it will follow. If it can't, then the mere presence of the metal won't have great influence. Remember that there may be many branches, so the damage to the mark might not have been from the main strike. Or it might have been a bullet. Or how about a small meteor!

[+Spoo]

I have no proof, but think the pitting you see here is from lightning. Part of PF1145.

 

http://img.Groundspeak.com/benchmark/lg/03...baa5b4484f0.jpg

 

It is the highest point on the mountain aside from the tower.

[Wintertime]

I like the meteor theory! Not that it's the most likely explanation, but it's the most interesting one! :-)

 

Patty

[+Klemmer]

I've seen some high rocky areas that I belive have been struck by lightning, but certainly not benchmarks! Fulgarites are neat. I've been tempted to dig for some nearby, but it's in a wilderness park, so probably not a good idea.

 

To quote myself from a cache log (since archived) near there:

"Has anyone else noticed the three large melted / burned areas just NE of the cache? I believe they are from lightning strikes, and have a special name, 'Fulgurites' from the Latin 'Fulgur' for lightning. The whole area around the cache looks to be a surface outcropping of a high iron content mineral (hematite?). Hence, the lightning attraction, I suppose, even though it's not quite at the peak".

 

So a benchmark struck by lightning would be a "Fulgarimetric Station"? What's the NGS code for that type station?

[+PFF]

Patty wrote:

 

I like the meteor theory! Not that it's the most likely explanation, but it's the most interesting one! :-)

 

I like it, too, Patty. A refreshing change from the usual conspiracy theories.

 

On the other hand, the photo SPOO posted clearly shows the effects of a UFO's exhaust during take-off and/or landing.

 

Paul

[+Mr Lost]

Patty wrote:

 

I like the meteor theory! Not that it's the most likely explanation, but it's the most interesting one! :-)

 

I like it, too, Patty. A refreshing change from the usual conspiracy theories.

 

On the other hand, the photo SPOO posted clearly shows the effects of a UFO's exhaust during take-off and/or landing.

 

Paul

Lasers.

 

Super secret government orbital mind control lasers test their accuracy on all kinds of things.

 

It's lasers.

[+BuckBrooke]

Team Gecko,

The hole looks rather symmetric and has sharp edges; I would expect that more from an impact/glancing blow of a physical object. There's usually a lot of heat involved with lightning, as it discharges, so I would have expected melting.

It's not clear to me that one can fall back on the "Wierd things happen with lightning" defense here. I like Geo's $0.02

[+Team Gecko]

Team Gecko,

    The hole looks rather symmetric and has sharp edges; I would expect that more from an impact/glancing blow of a physical object.  There's usually a lot of heat involved with lightning, as it discharges, so I would have expected melting.

    It's not clear to me that one can fall back on the "Wierd things happen with lightning" defense here.  I like Geo's $0.02

Thanks for the great feedback. BTW, here are a couple of larger images that seem to show metallic melting.

 

 

 

Frankly, it looks a bit like a material flaw as you might expect if someone applied a welding torch to it (at the manufacturer?). Too bad I was not able to do any chemical analysis.

 

I kind of like the meteor theory without worrying too much about the implausibility of the physics.

-Gecko Dad

[Wick246]

Looks like a lightning strike to me. I have seen similar marks on aircraft that have been struck.

[+Crystal Sound]

I have to agree with the lightning strike. Being high on a peak I would expect there to be a few lightning strikes on occasion.

 

The energy released in a lighting strike is very intense. There is so much energy released, that not only is metal melted, but actually vaporizes. Sometimes there is evidence of melting, but often metal is vaporized so quickly, that there isnt much metal that is in a liquid state long enough to flow to give it that melted look.

 

I've seen similar pitting on metal parts of insulators.

 

If you look closely at the "D" in GEODETIC, there is what appears to be a small pit. Also at the "CE" of REFERENCE is an imperfection. They look to me, like the results of a sidestream (tentacle) arcing of a strike.

 

Bullet (and other) impacts tend to have some "smearing" when at an angle, and more a cupped hole.

 

I'm not saying it "is" or "isnt", but it does look to me like lightning damage.

[+GEO*Trailblazer 1]

Another explanation may be that if it is located in a Hi density ore-mineral area.

Sulpher oxides would also be present.

Causing acidic type corrosions.

The bigger pictures make that look a little clearer.

 

But I like the other theroies as well.

[+BuckBrooke]

Hmm. Your lightning arguments carry some weight. Here's another (similar?) example from the galleries, RX0362, set vertically in a concrete overpass support pillar:

 

 

It has different holes, but also has that splattering. However, there's so many things that could happen to a disk. This one's interesting, as it looks like the damage goes through the disk.

Edited February 1, 2006 by BuckBrooke

[Photobuff]

Wow, that's neat, and the damage probably does go through the mark. Think about the current path- though a rock it would be minimal, but through a concrete structure- rebar!

[+Spoo]

I don't mean to muddy the issue............BUT...........

 

Several years ago, my company took several lightning strikes over several days and destroyed hundreds of thousands of dollars in test equipment on our outdoor ranges. These strikes, mostly against copper and brass antennas and feedlines, manifested themselves in many ways, from small blackened holes to fist size holes with melty edges.

 

My company cut me loose to learn all I could about lightning and to prevent further damage. I learned alot from this experience and am proud to say that since then, we have not taken any more damage.............

 

BUT..............

 

One thing I learned is....."you do what you want and lightning will do what it wants". Someday, my record will fall with a good strike.

 

My point is that lightning may simply dance over an object, it may drill holes, it may blast apart its metal victim and leave sharp edges or it can just softly melt or pit the item.

 

BUT....so do many other things. Only on active equipment and within hours of a strike was I able to verify lightning vs normal aging, corrosion or rot. We have also been able to examine known bullet holes from hunters and it is surprising how often the damage cannot be differentiated from lightning.

 

Coudos to everyone that finds these anomolies on a BM and carefully records, photographs and reports them whatever may be the cause.

 

Edit note: colerected spelllings

Edited February 1, 2006 by Spoo