Low Yield Nuclear Weapon Hypothesis - version 2
This is the latest version of my hypothesis. It's broken down into two sections. The first is a simple narrative of the events. Each section is numbered. Below the narrative is presented a corresponding discussion, argument and explanation of the narrative with corresponding numbers.
1. On the 1st feb 1959 on the North East slope of Kholat Syakhl at about 300 metres from the summit. The Dyatlov group made camp and began to settle in. Some time during the evening, one or more of the group noticed something strange going on outside. Some of the group members (Semyon, Thibo) put on some of their clothes and shoes and went outside to take a look at what was going on. Semyon grabs a camera from the tent to try and take some photographs.
2. An intense bright light from behind the summit of the mountain lights up the whole landscape, casting long dark shadows where the light is blocked by the peaks and ridges of the mountain. A low yield nuclear device has detonated several km away to the south west. 5 to 10 seconds after the bright flash a shock wave reverberates over the top of the mountain hitting those standing up outside and rattles the tent. The shock wave however causes no serious injuries, possibly some minor injuries, and has a deafening sound. A bright orange glow fills the sky above the summit. The Dyatlov group are shaken up by the shock wave and then a blast of wind capable of knocking people over. This may have sparked a panic within the group, causing them to leave the tent trying to understand what was going on.
3. Several minutes later a thick smoggy cloud starts to flow over the top and around the sides of the summit, rolling down the slope and hugging the ground. When it gets to the tent and the Dyatlov group the true horror of this dusty cloud is revealed as the dust hits their eyes, lungs and throats, causing severe irritation, burning and restricted breathing. The group have no choice but to try and get away. There is no time to collect anything from the tent as they are being overcome by the toxic, noxious dust cloud. Their instinct is to try and get away and they begin to move down the slope in the opposite direction to the dusty smoggy cloud and the point where the device was detonated.
Descending the slope
4. One of the group already has a flashlight in hand, but the smoggy haze is difficult to see through in the dark. They gather together and move down the slope in single file, holding on to each other not to get lost in the dark smog. As they decent they cough and gag and choke for air, their eyes burning. 400 metres down the slope the flashlight goes out, the batteries spent. The torch is switched off and discarded. As they get closer to the bottom of the slope and the tree line, they can see a large cedar tree poking above the layer of dusty smog and they head for the tree.
The Cedar tree
5. When they get to the cedar tree, they make a desperate attempt to scramble up the tree. It is difficult for some who are suffering early frost bite on their fingers and toes. They are pushed, shoved and hauled up where possible, sustaining many scratches and abrasions in the process. Zina possibly sustains a significant bruise slipping and falling against a tree branch. Some of them manage to get high enough to gain access to more breathable, less acrid air. Maybe some don't get high enough to completely remove themselves from the smog layer flowing down the mountain. Now they have to hang on and wait until the smog layer dissipates. They clear some branches to try and see up the slope where the smog is coming from. Some of the group clinging to the tree gasp for air, but it is too much and they lose consciousness and fall. Semyon, Lyuda and Thibo all fall from high up in the tree and land hard on the ground sustaining significant injuries. Dorishencko desperately tries to cling on to the tree with his frost bitten fingers and numb hands.
6. The fog does eventually clear, and they climb down the tree and attend to the injured on the ground as best they can. The two Yuris are severely frost bitten and cold as they have less clothing on. Those still capable gather wood to make a fire in a desperate attempt to keep warm. They know that they can't survive or make it back to the tent without a significant heat source to warm their bodies. They build the fire and try to get warm. But for the two Yuris it is too late. They die first, but not of hypothermia. They die as a result of severe hypoxia and Odema resulting from acute nitrogen dioxide exposure. The cold just helped to speed this up.
7. Semyon, Lyuda and Thibo lie on the ground. Thibo is unconscious and Semyon and Lyuda are either unconscious or in severe pain.
8. The fire is not enough to ensure their survival and they know they cant carry the injured back to the tent, so they scout around for a more sheltered area and find the ravine 70 metres away and decide it would be a better place to build a shelter. They start to cut down the young fir tree branches around the cedar in a radius of about 20 metres so that they can transport these to the ravine to make a den. By collecting them around the cedar tree they can also stay warm by going back to the fire, instead of collecting them at the ravine where they could succumb to the cold before they have finished the den. They transport the fir branches to the ravine and build a makeshift shelter. After removing the remaining useful clothing from their dead friends and distributing it (e.g. Wrapping Lyuda's foot) they transport their injured friends to the ravine and the den. All the while they struggle to breath as the residual effects of the smog cloud continue to cause them problems. The group realise that they need their equipment if they are going to survive. Dyatlov, Zina, and Rustem decide to return to the tent after warming themselves by the fire, leaving Kolevatov to attend to the injured in the ravine.
9. Lyuda dies from a combination of her severe chest injuries and hypoxia. Her hat and coat are transferred to Semyon. Semyon succumbs to the same fate some time later. Thibo slips away from a severe head injury, the cold and hypoxia. Kolevatov is the last alive in the ravine. He clings to Semyon and he too succumbs to the effects of the cold and severe hypoxia.
10. Dyatlov climbs the slope with his friends, but his strength leaves him as he gasps for air. He falls unconscious and slowly the cold takes him. Rustem is next, he falls hitting his head as he staggers up the slope with Zina, his lungs burning. They know if they don't get to the tent they will die. Rustem falls and dies of hypoxia and Odema. Zina, falls the same way a little further up the slope. It is over.
DISCUSSION AND ARGUMENTS FOR THE ABOVE NARRATIVE
1, FACT - Semyon and Tibo were the better dressed for the weather conditions. They had put on footwear, hats and several layers of clothing.
Even so they did not have all their outdoor clothes on so were not prepared for a long hike. They may have been on watch that night.
It is possible that they went out to relieve themselves and noticed something going on in the sky.
FACT - When Semyon was found he had his camera around his neck.
It is unlikely that Semyon was taking photos inside the tent that night while dressed with his boots on. Something must have prompted him to get his camera from the tent before things started to go bad. It is also extremely unlikely that he grabbed his camera after things started to go bad given that the rest of the group did not even have time to get their footwear. He must have already had his camera with him when they left the camp in haste. So it is very likely that he thought there was something worth taking a photo of outside the tent before things turned really bad.
After the detonation of the device, it is likely that several others scrambled out of the tent to find out what was going on. They put some warm clothes on but did not put on their boots probably because they did not expect to be leaving the camp site. Lyuda took her fur hat and coat which was later found on Semyon in the ravine. Kolevatov or one the others probably removed it from Lyuda and put it onto Semyon after she died. Zina, and Igor had several layers of clothes but no boots. Some of the group were still scrambling to get dressed when they were forced to leave the camp. Rustem had managed to put on one felt boot, but left before he had put on the other one. It is likely that some of them were standing outside for a short time before they were forced to hastily leave the camp site with no time to collect any more of their clothing or equipment. The two Yuris were probably still in the tent when the group were forced to leave and had little time to put any real warm clothing on. There was probably a short period ( minutes ), where they knew something unusual was happening, but didn't realise how much danger they were in.
2. Why a nuclear device?
FACT - the investigation requested that radiation checks be carried out.
There is no logical reason for this unless the authorities suspected that there was some kind of nuclear involvement. At this point they obviously didn't know what had happened themselves but may have suspected the cause to be a nuclear test that they were aware of. They wanted to know what had happened. It is possible that Kholat Syakhl had been selected as a test site due it's isolation, lack of vegetation and animal life, or it is possible that it was not deliberately selected, but that the delivery system of the nuclear device failed and deviated from its intended course.
FACT: access to the area was restricted for 3 years after the event.
This is enough time to allow any residual radiation levels to fall off or to clean up the site.
There is also anecdotal evidence that the helicopter pilots refused to take the bodies from the ravine on board unless they were in zinc coffins. They may have known something or possibly had heard that radiation checks had been carried out.
Ivanov said he had noticed scorch marks on the tops of the trees, but not in a uniform pattern. This could have been the result of a nuclear heat flash and ionising radiation pulse, but because the detonation was behind the summit of Kholat Syakhl only those trees in direct line of site of the blast would be scorched, creating the appearance that heat beams had been fired at the trees. The optimum height of a low yield 1 to 3 kilotonne device would be between 200 and 500 metres above the ground. If it was a nuclear device being tested then this is likely to be the range of detonation heights.
FACT - some of the clothes were found to have traces of radiation above normal background levels.
It was 3 weeks before the group were found. Any significant levels of radiation would have decayed back to safe levels or blown/ washed away by this time only leaving traces. Clues like the clothing. Also the snow around the tent had been scoured away by the wind. Thus the elevated foot prints, meaning that there would be little evidence of radiation around the camp site as any fall out on the snow would have been blown away. Further down the slope the snow was deeper and any residual radioactivity would have been buried and shielded from detection.
There is anecdotal evidence from other people around the area up to 70km away of orange orbs, or fire balls in the direction of the mountain. To see something as a sphere or orb from 70km away would mean it had to be pretty big. About 500 metres would make it about as big as the moon in the sky from 70km. A low yield weapon like this would produce a fire ball about 500 metres across. This could be coincidental, and some other unrelated thing, but if it was some kind of ordinance it would have to be pretty spectacular to be seen from 70km and described as it was.
Also the device being detonated at its optimal altitude and behind the mountain would mean that the Dyatlov group would be quite well shielded from the worst effects of the heat flash and ionising radiation. From several km away, the shock wave over pressure would only be several psi and not enough to cause significant physical harm. But it would have been very scary. The wind blast may have been strong enough to knock anyone standing up outside the tent over, and would have rattled the tent possibly partly blowing it down. The heat flash, shock wave and wind blast would have been very scary, prompting those still in the tent to start getting dressed and scramble out.
FACT: Rustem was found with one felt boot on indicating that some of the group were in the process of getting dressed, but that they didn't have time to finish before things started to go bad. The pile of boots near the entrance was disorderly indicating there was a mad scramble to get past them and outside. Some of the group may have scrambled out of the tent poorly dressed to find out what was going on. Up to this point there would be no immediate need to leave the camp site as the heat flash, radiation pulse, shock wave and wind blast have passed and has not caused significant harm. The group would have observed the glow of the fire ball rising behind the summit and may have stood there for several minutes in bewilderment trying to understand what was going on. They also may have realised that some kind of weapon had been used.
3. The fire ball from a nuclear device is made of the vaporised components of the device and radioactive materials. It is also composed of a large quantity of nitrogen dioxide gas formed by the reaction of oxygen and nitrogen at temperatures in excess of 1600 Celsius. About 5 tonnes of nitrogen dioxide is produced per kilotonne of yield. Thus a 1 to 3 kt device would produce between 5 to 15 tonnes of nitrogen dioxide gas. The fire ball would expand and cool rapidly. Initially, the fire ball would rise due to its buoyancy, but because the air was so frigid and cold that night it would have cooled very rapidly indeed. Nitrogen dioxide is a liquid at temperatures below 21 Celsius. As the fire ball cloud cools nitrogen dioxide would start to condense and precipitate as micron size droplets with a range of droplet sizes. As the cloud continues to cool the nitrogen dioxide will dimerise forming N2O4. At a temperature of less than -11 Celsius N2O4 freezes as a white solid. The small micron size droplets would freeze into solid white micron size dust like particles. This would happen quickly. These particles would begin to fall forming a collapsing smoggy dust cloud that hugs the ground and moves with the wind. For a 150 micron dust particle it's settling rate would be about 0.5 metres per second, which means that within a km or so, the dust cloud would touch down on the ground, spread out and move along with the wind. The south west slope of the mountain was bordered by ridges, creating a kind of bowl that would have channeled a dust cloud up toward the summit of the mountain.
The size of this cloud would be significant maintaining concentration > 100 ppm ( significantly above LD50) over many kilometres. E.g 50 square km blanket of noxious smog. Concentrations >> 100 ppm would be intolerable and force people to try and get away. It should be noted that the small dust like smog particles would not be very reactive unless they came into contact with a warm surface, enough to cause the dust particles to convert back to NO2 ( e.g. Human skin, eyes, lungs and mucous membranes at 37 Celsius). A small solid particle would be converted in much more gas and result in high concentrations in the lungs.
Given that the Dyatlov group made their way hastily down the slope in the direction of the wind it is reasonable to assume that they were trying to get away from whatever threat there was by moving in the opposite direction away from fire ball and cloud. This would be the most instinctive thing to do. This would place the fire ball and dust cloud to the south west of the camp site and over the summit of the mountain. It would place the dust cloud upwind of the group.
So not long ( several minutes) after they were standing outside the tent wondering what was going on, a large smoggy toxic, radioactive noxious cloud of dust would come rolling over the top and around the sides of Kholat Syakhl directly at them. When the cloud reaches them they would have no choice but to try and get away from it as the dust hit their eyes and lungs causing severe burning and irritation. I think it is at this point that they would have panicked and headed down the slope, not waiting to collect any more of their gear.
4. FACT: about 8 or 9 sets of foot prints were seen moving down the slope away from the tent in what seemed to be single file.
FACT: 400 metres down the slope a flash light was found, switched off, batteries spent.
I can only imagine that due to the darkness and possibly the noxious fog cloud visibility would have been very poor. It would make sense to go in single file. The person with the flash light up front, and the rest behind holding on to one another. The acute exposure to nitrogen dioxide would have made it very difficult to breath and the conditions during the decent down the slope would have been horrendous. Their instinct would have been to try to get away.
As they get near to the tree line they make out the tall cedar tree. It is possible that the top of the cedar is visible above the worst of ground hugging noxious smog, so they head for the tree to try and climb up it to get to more breathable air.
5. The cedar tree is a key clue to the events of the night. It was prominent at the tree line. It was tall. Why did they go there in particular?
FACT: the tree was climbed up to at least 5 metres, where there were broken branches.
FACT: Dorishenko had particles of moss and pine needles in his hair. He had bruises on both his shins, a cut on his left forearm, abrasions on his left elbow, abrasions and bruises around his arm pits and severe frost bite on his fingers and toes.
FACT: Krivonischenko had similar cuts, abrasions and bruises to legs, hands face and forearms.
FACT: Zina had cuts abrasions to hands, face and a large long bruise on her side
The moss, needles in hair and minor injuries could be consistent with a person trying to scramble up a tree, especially if the person had frost bite and needed to try and climb and hold on using arms and legs.
If the cedar tree was only used as a look out or vantage point or to collect fire wood why would those with frost bite want to climb the tree, when it would be extremely difficult to do so, especially when there were others with less frost bite and better dressed. It wouldn't make sense, unless they were all trying to escape from something. Something closer to the ground. Something that couldn't climb trees and didn't leave any foot prints - like a blanket of noxious fog/smog?
It's difficult to say how long they would need to stay on the tree? It may have been 30 minutes or an hour before the smog layer dissipates. It also,would depend on if there was more than one device tested that night.
Acute nitrogen dioxide poisoning - as well as being acrid and irritating has a delayed effect. The acrid fumes would cause restriction of breathing and gasping for air. Dissolved in the blood nitrogen dioxide results in methemoglobin which inhibits oxygen transport. Restricted breathing coupled with methemoglobin can result in insufficient oxygen and hypoxia. This can result in confusion, fatigue and loss of consciousness. These are not good symptoms to have when you are over 5 metres up a tree.
In this hypothesis it is proposed that the group chose the cedar because it was tall and they use it to try and get above the noxious gases. They all climbed as best they could. I suspect they climbed to higher than 5 metres but there isn't any clear evidence on this.
If the delayed effect of acute NO2 poisoning took effect while they were on the tree then it is credible that some of them could have lost consciousness.
It is proposed that Lyuda, Semyon and Thibo lost consciousness and fell from the tree to the ground, sustaining significant injuries. The injuries would be similar in terms of the amount of applied force ( at least 2 tonnes of pressure), but different depending on how they landed. Lyuda and Semyon and Thibo were wearing several layers of warm clothes. This provides a lot of padding and the impact of a fall would be cushioned and the forces spread out across the body area. Therefore unless they had landed on something sharp the damage to external soft tissues would be minimised. Thibo was wearing 2 hats. A fur hat and a sports hat. So if he landed hard on his head the hats would again spread some of the forces across that part of his head minimising cuts and scratches to the soft tissues. Some of the others may have fallen too but the injuries would depend on how high they were in the tree and whether they fell all the way to the ground. Zina for instance may have slipped, bruised her side against a branch and caught hold to prevent her falling from the tree completely.
6. When the noxious smog eventually clears, those still in the tree climb down and try to attend to the injured. They start collecting fire wood to make a fire and eventually get one going. For the two Yuris though it is too late. The acute NO2 poisoning leads to severe hypoxia, Odema and death, speeded up by the cold conditions.
FACT: grey foamy liquid found on Dorishenko's face was fluid from his lungs. Odema.
FACT: At autopsy the urine in Dorishenko's bladder is low and not consistent with death from hypothermia.
FACT: the fire did not help them to stay alive even though they were close enough to sustain burns.
At some point the clothes of Dorishenko and Krivonischenko were removed and shared out. Lyuda had Dorishenko's sweater and some clothes which had been wrapped around her foot. I would say that these were put on her by the others while she was unconscious. It may also be possible that Krivonishenko made a selfless and noble sacrifice and gave Lyudua his sweater on the decent from tent ( women and children first ). However, the sweater may also have been taken after his death.
7. There is not much to say on this. Lyuda and Semyon and Thibo were dying. Lyuda may have died here even before she was moved to the ravine. They were probably unconscious due to severe hypoxia. While they were at the cedar the remaining functioning group would have realised that there was no way to get the injured back to the tent. They may have decided at this point to look for a suitable place to build a shelter to protect the injured and then to make an attempt to go back to the camp to get more clothes and equipment. They scouted around and found a more sheltered place in the near bye ravine. They start cutting down the small trees around the cedar to use to make the den. This way they could use the fire to maintain their body temperatures while collecting the materials to build the den.
8. They then made several trips between the cedar and the ravine, transporting materials to make a den. They build a basic snow den and move the injured, dragging and carrying them to the den. While dragging them some of the pieces of clothing taken from the two Yuris, falls off in the snow and trousers etc are torn. When the shelter is finished Dyatlov, Zina and Rustem decide to make an attempt to go back to the tent. They know they need their equipment if they are to survive. They leave Kolevatov at the ravine to look after the injured.
10. Dyatlov and his two friends warm themselves by the fire at the cedar before setting off for the tent together. But the effects of the NO2 poising catch up with them and they struggle from hypoxia and fatigue. Dyatlov falls exhausted and can't go any further. He succumbs to the cold and dies of hypothermia. Rustem falls next, but he dies of hypoxia and nitrogen dioxide poisoning before the cold takes him. Zina falls a little further up and dies from hypoxia and hypothermia.
FACT: Dyatlov has urine in bladder consistent with hypothermia.
FACT: Rustem has an ice bed and the urine in his bladder is not consistent with death from hypothermia.
Rustems injuries could be explained if he was struggling to stay conscious and fell repeatedly while trying to climb the slope back to the tent.
9. Back at the ravine Lyuda, Semyon, Thibo and Kolevatov all eventually die from a combination of their injuries, the cold and nitrogen dioxide poisoning. Dyatlov, Zina and Rustem never come back. The deaths of Semyon, Lyuda and Thibo can be explained. Their injuries combined with the cold would have killed them even without nitrogen dioxide poisoning. However, Kolevetov did not have such significant injuries. He was reasonably dressed and could have taken more clothing off Semyon, and Thibo after they had died. He was also better sheltered from the cold in the ravine and the makeshift den. He could have even went back to the cedar and the fire to keep warm and yet he died too. His jacket was unbuttoned and unzipped. This is very odd unless there was some other thing that was acting on them to kill them, like nitrogen dioxide poisoning. There is evidence that suggests that Dorishenko' and Rustem demise was not from hypothermia, and their physical injuries were described as non life threatening.
By the early hours of the next day they are all dead and it is over.