The series of shockwaves from this explosion in a tunnel

the Tunnel Shockwave, series of exposions in a tunnel
tunnel being blown up causing a shock wave

A série de ondas de choque dessa explosão em um túnel
tunel sendo explodido causando uma onda de choque
Can anyone explain why this occurred?
comment bellow

tunel sendo explodido causando uma onda de choque

[GrouchyGander]

That initial cloud coming towards you at that speed is terrifying!

[AbWischBar]

Not sure somebody answered that yet but ... the waves bounce back and forth because the waves cannot spread but instead get reflected at each end. Outside, sound or shock waves from blasts would spread in all directions and become weaker, but here the tunnel shape keeps things focused. This is actually what happens inside flutes, organ pipes or any other tubular instruments (the bouncing - not the explosions) and exhaust pipes - the sound gets trapped and the pitch generated depends on the length of the tube, which determines the travel time of a reflection before it turns back.

The fluffiness (i.e. that you can see the waves) is due to the fact that the explosion is a sudden and high pressure event - a shock wave. It has a leading high pressure front, followed by an almost equally strong drop in pressure. This rapid pressure drop is what causes condensation. Air at a given temperature and pressure can hold a certain amount of humidity in gaseous form. If the air's pressure suddenly drops its temperature will too, and can no longer hold the same amount of humidity. All excess humidity turns into small liquid droplets. In shock waves, this only happens close to the wave front so the air gets cloudy where the wave is and returns to normal once it passed.

Edit: initially, this was really meant as a simple explanation for the curious ones. I am overwhelmed by the number of reactions and questions. I have slightly modified the original comment to work in some clarifications. But since people liked the "shortness" I will leave it at that. There are however, more detailed discussions in the thread below.
But overall I am happy for the sincere interest and thanks - both for the thumbs up and questions / discussions and the stuff I learned from this thread.

[coba]

"your hearing loss is not work related"

[chewy]

This is the coolest thing I’ll forget about immediately

[Usernamestill_Unavailable]

The fact that you can see the wave bounce back and forth a few times is epic

[R.DeMora]

This is why you never run into a tunnel to avoid an explosion. If the pressure wave wasn't strong to kill you outside it might be strong enough INSIDE.

[lekoopa]

Claustrophobic people when a big cloud wall comes in front of them in a quite small tunnel:

[_Triangularity]

I’ve felt shockwaves from being in the military around explosions. It’s not like high speed wind, its a completely different experience. It’s like all of the atoms in your body are shifting over a bit and coming back to their original place. Like the wave passes through you instead of just a force pushing around you.

[Michael-ufhz]

Pretty impressive how this person kept the camera steady, especially when you compare it to his friend to the left. I feel like something that loud and intense is hard not to flinch from, he must have alot of experience.

[morsz]

Judging by the number of frames between the explosion and the shockwave coming back, we can estimate that the tunnel infront of the camera is about 183.5 Meters long. Edit: for those of you asking, I calculated it by counting how many frames it took for the Shockwave to bounce back (as I mentioned earlier) then, I took the average speed of sound, and divided it into the number of frames (considering that the video is at 60 fps), giving me the answer.

[jackhaugh]

My dad was a mining engineer forever in PA back in the day, and my Grandfather was the VP in charge of safety for the same mining company. They had to get Oxygen into the mine for the miners to breathe, but also evacuate all of the Methane gas out of the mine so it wouldn’t explode when encountering sparks from the mining apparatus.
One day a mine DID explode. It happened during “miners vacation “ which was a one week period when all of the mines would shut down at the same time, and everyone went on vacation. There was only one person present in the mine when it happened whom was a supervisor and stayed behind that week to monitor the mine.
I remember we at the beach in Ocean City, MD when it happened, and we had to leave as soon as it happened so they could begin rescue operations.
My dad said when they found this unfortunate souls body, it was as thin as a sheet of paper because the pressure of the blast basically crushed his body against the shaft of the mine. That’s how powerful mine explosions are.

[zilchbupkis]

That’s like being inside a gun barrel without the projectile being flown at you

[masterdementer]

My father works in the mining sector as a maintenance manager, and this type of blasting happens very frequently. The base camp is about 1.5-2 km away from the mining site and I could hear loud explosions from that far.

[bdawg]

Imagine how big of a badass you would feel like, saying “fire in the hole!” And pressing the button for that explosion

[shikyokira]

not many people have experienced a shockwave before. A shockwave is like an uneasy feeling of energy going through your body. Your inner organs can actually feel the vibration, making the feeling for first time super weird

[docwiz]

The speed of that fuse is just amazing. The first second you can see the line streaking to the end of the tunnel almost immediately.

[katraena]

Watching the sound wave barrel toward you must be one of the most intimidating things to witness.

[jok]

I love how at the frame the guy hits the detonator the camera's shutter speed cannot keep up and you can see the line between the lit up parts of the detonation line and the unlit ones that were taken a fraction of a second sooner.

[bungusdoogungus]

Me and the boys committing a lil bit of tom-foolery in the particle accelerator

[spaghetti_exe]

It’s always interesting seeing how, in the grand scheme of things, sound is actually pretty slow.

My god, how did a whole war break out in the replies?