Syria Chemical Warfare: Analysis & Probabilities

[Office_Shredder]

penguin, your link got cut off and is literally directing to a location with a ... in the middle of it (in particular, it no longer points to a specific article)

 

[epenguin]

Thank you. Depending where I am coming from I can either see it or not. They surely won't mind me reproducing the article here.

http://www.hrw.org/news/2013/09/17/dispatches-mapping-sarin-flight-pathDispatches: Mapping the Sarin Flight Path
September 17, 2013
Josh Lyons
Related Materials:

Syria: Government Likely Culprit in Chemical Attack
September 10, 2013
Press release

The UN inspectors investigating the chemical weapons attack on two suburbs in Damascus last month weren’t supposed to point the finger at the party responsible for the killings. But even so, the Sellstrom report revealed key details of the attack that strongly suggest the government is to blame, and may even help identify the location from which the Sarin-filled rockets that killed hundreds of people on August 21 were fired.

In appendix 5 of their report, after describing the size and structure of two rocket delivery systems used, they go one step further and actually reveal the direction some of the rockets likely came from. Using standard field investigative techniques examining the debris field and impact area where the rockets struck, the report provides precise azimuths, or angular measurements, that allow us to work out the actual trajectory of the rockets.

“Impact site number 1 (Moadamiya) and impact site number 4 (Ein Tarma),” the inspectors wrote, “provide sufficient evidence to determine, with a sufficient degree of accuracy, the likely trajectory of the projectiles.” They go on to say that 3 of the rockets they inspected had bearings of 34 and 35 degrees for 2 of the rockets that landed in Moadamiya, and 285 degrees for 1 of the rockets that landed in Ein Tarma.

Connecting the dots provided by these numbers allows us to see for ourselves where the rockets were likely launched from and who was responsible.

The two attack locations are located 16 kilometers apart, but when mapping these trajectories, the presumed flight paths of the rockets converge on a well-known military base of the Republican Guard 104th Brigade, situated only a few kilometers north of downtown Damascus and within firing range of the neighborhoods attacked by chemical weapons.

According to declassified reference guides, the 140mm artillery rocket used on impact site number 1 (Moadamiya) has a minimum range of 3.8 kilometers and a maximum range of 9.8 kilometers. The Republican Guard 104th Brigade is approximately 9.5 km from the base. While we don’t know the firing range for the 330mm rocket that hit impact site number 4, the area is only 9.6km away from the base, well within range of most rocket systems.
Click to enlarge map

This isn’t conclusive, given the limited data available to the UN team, but it is highly suggestive and another piece of the puzzle.

While this base will be an early port of call for international teams charged with securing Syria’s chemical weapons under a US-Russian plan to prevent future attacks, it is critical we do not forget about Ghouta’s victims and bring those guilty of this war crime to justice.

We keep saying this because it matters so much: it is vital to hold accountable those who have used chemical weapons in the recent past. The UN Security Council – including Russia and the US – should refer the situation in Syria to the International Criminal Court as part of the upcoming resolution. Only by authorizing an impartial, independent investigation will we ensure justice for the victims in Ghouta.

I have copied the illustrative image from the Times though there is another one in the Human Rights Watch article, I don't know how stable it will be here.
http://www.thetimes.co.uk/tto/multimedia/archive/00453/Strikes_453134a.jpg

 

[chemisttree]

Does this, tracing trajectories of rockets fired at the relevant the time http://www.hrw.org/news/2013/09/17/d...in-flight-path that point to HQ of the regime's elite Republican Guard change Chemsttree's or anyone's view of what happened?

ABSOLUTELY NOT! The UN report is garbage! Especially the portion describing the trajectories! I leave to you and everyone else who will take the time to critically evaluate the report to draw their own conclusions. If an eighth grader turned this into me, I would have them in the principal's office for falsifying data.

 

[Office_Shredder]

chemisttree, can you point out specifically what's wrong with the trajectory explanation?

 

[edward]

ABSOLUTELY NOT! The UN report is garbage! Especially the portion describing the trajectories! I leave to you and everyone else who will take the time to critically evaluate the report to draw their own conclusions. If an eighth grader turned this into me, I would have them in the principal's office for falsifying data.

So does this mean that you think the attack was carried out by the rebels. We only have two sides to pick from. Early on, some extremely right wing news sites showed videos of rebels launching crude rockets supposedly laden with gas.

WND was one of them.

http://www.wnd.com/2013/08/video-shows-rebels-launching-gas-attack-in-syria/

BTW that blue warhead in the second video looks like a refrigerant 134A container to me.

On the other side we have the UN report backed by a credible institution.

The inspectors had little time and the sites that they went to show that much of the evidence has already been disturbed or removed. They did find one case where a rocket landed without exploding a warhead – indicating that it may have carried gas. The inspectors later went to a nearby site that had suffered a gas attack – possibly from the warhead of the rocket. They took physical data on the rocket body showing it was a 140 mm rocket some 630 mm long with inscriptions in Cyrillic, 10 jet nozzles, and a metal electric contact plate (firing mechanism) in the center.

http://csis.org/node/46709

 

[Bobbywhy]

In appendix 5 of their report, after describing the size and structure of two rocket delivery systems used, they go one step further and actually reveal the direction some of the rockets likely came from. Using standard field investigative techniques examining the debris field and impact area where the rockets struck, the report provides precise azimuths, or angular measurements, that allow us to work out the actual trajectory of the rockets.

“Impact site number 1 (Moadamiya) and impact site number 4 (Ein Tarma),” the inspectors wrote, “provide sufficient evidence to determine, with a sufficient degree of accuracy, the likely trajectory of the projectiles.” They go on to say that 3 of the rockets they inspected had bearings of 34 and 35 degrees for 2 of the rockets that landed in Moadamiya, and 285 degrees for 1 of the rockets that landed in Ein Tarma.

Connecting the dots provided by these numbers allows us to see for ourselves where the rockets were likely launched from and who was responsible.

The two attack locations are located 16 kilometers apart, but when mapping these trajectories, the presumed flight paths of the rockets converge on a well-known military base of the Republican Guard 104th Brigade, situated only a few kilometers north of downtown Damascus and within firing range of the neighborhoods attacked by chemical weapons.

According to declassified reference guides, the 140mm artillery rocket used on impact site number 1 (Moadamiya) has a minimum range of 3.8 kilometers and a maximum range of 9.8 kilometers. The Republican Guard 104th Brigade is approximately 9.5 km from the base. While we don’t know the firing range for the 330mm rocket that hit impact site number 4, the area is only 9.6km away from the base, well within range of most rocket systems.

The UN report did not specify how those compass readings were taken. According to this site: http://www.geo-orbit.org/sizepgs/magmapsp.html , the
Damascus magnetic variation (declination) = 5 Degrees East (of magnetic North).
If the quoted readings were not corrected for the 5 degree difference, would that affect the conclusion?

 

[Office_Shredder]

Considering the map in his post is already drawn to obfuscate the fact that the arrows don't actually meet at the center of the circle, I don't think a five degree difference will change things too much - in fact if the arrows should be rotated five degrees more to the west, they might meet at the center much more closely

 

[chemisttree]

Sure. The Report is predicated upon well-established methods of sampling, sample handling (chain of custody), training and analysis methods. Appendix 2 is devoted to referencing those methods for this report. There are no accepted standards or methods for any analysis of trajectory. Thus, this reports fails first in attributing an expertise where there is absolutely none.

There is discussion in Appendix 5 regarding the munitions found in the field. Much detail is presented regarding what can be measured (rocket tube diameter, number of bolts, size and shape, etc...) but no detail about what matters. What matters is the evidence that supports findings such as the original trajectory of the rockets. Appendix 5 has a section titled, "Considerations on the likely trajectory of the rockets." This section states:

Of the five impact sites investigated by the mission, three do not present physical characteristics allowing a successful study of the trajectories followed by the rockets involved, due to the configuration of the impact places. However, Impact site number 1 (Moadamiyah) and Impact site number 4 (Ein Tarma) provide sufficient evidence to determine, with a sufficient degree of accuracy, the likely trajectory of the projectiles.

So only two of the five impact sites were judged to have sufficient physical characteristics to allow a successful study of the trajectories followed by the rockets. The next paragraph contradicts this by introducing a third impact site that was shown to have a similar trajectory. More on that later.

The second the five sites that had physical characteristics to allow a successful study of the trajectory followed by the rocket is identified as "Impact Site Number 4" in Ein Tarma. At this site was found the 330mm rocket that contacted the surface in an area of earthy, relatively soft ground where the shaft/engine of the projectile remained dug in, undisturbed until investigated. This shaft presented no form of lateral bending, unlike many other 330mm projectiles found elsewhere. It pointed along a reverse trajectory of 284 degrees which represented an original trajectory of 105 degrees. This implies measurement to a precision of +/-0.5 degrees.

These are the two sites that were used to draw the lines back to an intersecting point within an area controlled by Syrian Government forces. Impact site 1 in Moadamiyah has a projectile that is reported to have contacted the corner of a building adjacent to where the impact crater was discovered. The motor section of the rocket is well-described as being a 140mm rocket capable of carrying a chemical munition. This rocket initially contacted the corner of an adjacent building and finally landed in the terrace of an adjacent building. The initial contact point was determined by following a line from the crater to damage to an existing fence/trellis work (later referred to as a "vegetal screen" existing over one of the adjacent walls) and was described as the corner of an adjacent building, its strongest part and most capable of deflecting the path of the projectile away from the original trajectory. The original trajectory of the projectile was traced along the line of travel after the rocket motor contacted the corner of the adjacent building, reported to be 215 degrees, so the authors believe that this part of the original projectile traveled undisturbed from the corner of the first building to its final resting place. This is bogus. When I told my wife of this impact trajectory being used to determine the original trajectory she laughed! She has years of experience as a ballistics engineer and knows of the virtual impossibility of determining the original trajectory of the original projectile after initial impact and ricochet of a PART of the original projectile! Unbelievable propaganda! It's truly mind-boggling. The author follows this with the absurdly accurate determination of an azimuth from a site determined to be of sufficiently poor quality to determine just this type of information! 214 degrees azimuth. 214 degrees! This implies a method capable of measuring the azimuth to a precision of +/- 0.5 degrees! Tell us of this method, please! Describe the method you used to determine this trajectory and what equipment did you use to accurately measure to a precision of +/-0.5 degrees! Tell us of the effect of the ricochet of the rocket motor on your "analysis"! Propaganda! Of course I've yet to discuss the obvious problem of the deployment of an explosive charge in flight and the loss of perhaps 1/2 to 2/3 of the mass of the original projectile and how that might affect the final trajectory. Why was this nonsense included in the report? None of it was referenced in the "Conclusions" section. For good reason, I say.

The description of both impact sites is qualified by the following paragraphs:

The time necessary to conduct a detailed survey of both locations as well as take samples was very limited. The sites have been well traveled by other individuals both before and during the investigation. Fragments and other possible evidence have clearly been handled/moved prior to the arrival of the investigation team.

...and

As with other sites, the locations have been well traveled by other individuals prior to the arrival of the Mission. Time spent on the sites was well used but limited. During the time spent at these locations, individuals arrived carrying other suspected munitions indicating that such potential evidence is being moved and possibly manipulated.

The impact site shown in the photos on page 20 of the Report show an example of the described 330mm rocket sticking out of the ground at the base of a pile of debris, not an impact crater at all. Was this potentially manipulated rocket used to determine the azimuth of the original trajectory by unknown and perhaps ad hoc methods?

We can draw no conclusions regarding the trajectory of these projectiles given the errors and obvious bias in this report. Unfortunately this casts the entirety of the report in the same light and so the Russians are right in their assertion that we don't have enough information to make a determination.

Unbelievable! How could such an important document be allowed to go to publication with such obvious errors?

 

[epenguin]

I have so far read only the summary by HRW. However I am not seeing how the accuracy of 0.5 degrees of which Chemmstree makes an issue is one. If it were 5 or 10 degrees it would hardly affect the conclusions much it seems to me.

 

[Bandersnatch]

I have so far read only the summary by HRW. However I am not seeing how the accuracy of 0.5 degrees of which Chemmstree makes an issue is one. If it were 5 or 10 degrees it would hardly affect the conclusions much it seems to me.

The point was not whether or not the result was 100% correct, but the supposed implausibility of such accuracy in measurement.

 

[chemisttree]

The point is that amateurs are doing something they are not qualified for with material that may have been moved. Epenguin, get out your protractor and determine the zone of uncertainty given a precision of 5 or 10 degrees. Keep in mind that the point of intersection is believed to have some significance where there is none. Two different weapons systems were used and there is no reason to believe that they both came from the same location. Also keep in mind that this was included in a report that may be used to justify our involvement in this mess.

What do you think it means when a report states that only two impact sites could be used to "accurately" measure trajectories and then three are presented. And one of the sites was of an obvious, well-described ricochet? Why is this included in the report? It calls into question everything else in the report as well.

 

[chemisttree]

So does this mean that you think the attack was carried out by the rebels. We only have two sides to pick from.

I still think it is very likely that government forces carried out the attack but this report is not sufficient to provide a "smoking gun". I believe this report betrays a bias against one side where there should be none.

 

[KWilliamsAF]

At this scientific site it should be possible to get some better informed considerations than I am finding elsewhere about the probabilities concerning what has happened in Syria.

There appears little doubt that a population has suffered an attack involving probably sarin, and I think mustard gas has been mentioned.

But then there have been doubts, indeed polemics, about who did the attack. The published US Government assessment .

http://www.whitehouse.gov/the-press...n-government-s-use-chemical-weapons-august-21

does not identify a smoking gun. The forthcoming UN inspectors' report is not expected to try and identify the attacker. But it may contain indications from which we could reason out probabilities.

In all the polemics I have seen so far (outside this site) the opinion of everyone appears determined by their political orientation and loyalties and what they want to be true, what they would like, or would best suit them, to be true. I would like to hear something more fact and knowledge-based here.

For me a crucial part would be this paragraph:

Syrian chemical weapons personnel were operating in the Damascus suburb of ‘Adra from Sunday, August 18 until early in the morning on Wednesday, August 21 near an area that the regime uses to mix chemical weapons, including sarin. On August 21, a Syrian regime element prepared for a chemical weapons attack in the Damascus area, including through the utilization of gas masks. Our intelligence sources in the Damascus area did not detect any indications in the days prior to the attack that opposition affiliates were planning to use chemical weapons.


Mixing? I know that modern chemical weapons are designed to be binary, i.e. the toxic agent is not carried about as such, but created by mixing precursors. Maybe they are mixed when needed or soon before? That implies well trained and officered troops, and implicates the regular army surely? Or regular units that have switched sides. However the document just says 'mixing' without explanation. As if everyone knew about it. Any comments?

Then I read in Wikipedia that, I don't know how usually, the mixing takes place inside the projectile shell. That implies that it is the side which has artillery, pretty much only the government side and it has certainly used it a lot.

The idea of binary weapons is safer storage. Can we infer that this has not been an accident? Or could the estimated 1,400 deaths from accidental shelling of storage facility and is just a fraction as dreadful as it cluld hve been with more primitive weapons?

http://www.mypixshare.net/files/img/user_uploads/displayimage.php?id=9xn4mido2q687055707.gif
Great discussion following this post. I'm curious of the probability of an accidental shelling of a chem storage facility.

 

[chemisttree]

Pretty low for a binary chemical agent. Both parts are not stored in the same place and even if they were, mixing would be... problematic. The attack was intentional to have been as deadly as it was.