Talk:Pyroclastic flow

message: From the Hekla article, a volcano in Iceland:
:Up until now, it has always been assumed that Hekla was incapable of producing that most dangerous of volcanic phenomena, the pyroclastic flow.
Is there a reason scientists would believe this, is it something about the shape of the mountain, kind of material that the mountain can eject, or simply because there was little evidence of previous pyroclastic flows? In the pyroclastic flow article it says that the phenomena happens in "some" eruptions, but doesn't really expound on how/why they can happen, anyone have some more info? --Fxer 18:03, 30 January 2006 (UTC)
thread_title:  When/why are flows unlikely to happen? 

message: Everyone seems to have missed it: Branney and Kokelaar, Pyroclastic density currents and the sedimentation of ignimbrites. Completely new thinking, pretty much abolishes terms like flow and surge. Widely accepted. Main tennet: Deposits only represent the conditions at the flow boundary layer, deposits formed by proggressive aggradation, so terms like fully dilute and granular fluid only apply to the base of the current.
Russjass (talk) 09:37, 13 May 2008 (UTC)
thread_title:  Seminal paper published in 1992 

message: Pyroclastic flows are not gravity currents. They are the same as turbidity currents. they are driven by the density contrast, they can move on a slope of less than 1 degree  —Preceding unsigned comment added by Russjass (talk • contribs) 09:42, 13 May 2008 (UTC)
thread_title:  Gravity current? 

message: Herbert Huppert is Professor of Theoretical Geophysics and Director of the Institute of Theoretical Geophysics at the University of Cambridge. He states the dust cloud created during the WTC collapse of 9/11 to be a Pyroclastic flow. 
http://plus.maths.org/issue20/features/huppert/  —Preceding unsigned comment added by Cmatrix (talk • contribs) 21:57, 3 October 2008 (UTC)
replies: text: Read Talk no. 4 - "And yes, the 9-11 collapse was a gravity flow, but it doesn't seem to fit the volcanologic usage of the term pyroclastic flow."Guanlong wucaii 12:35, 22 June 2009 (UTC)
thread_title:  Pyroclastic clouds are not only related to geological phenomena 

message: I have heard that nuée ardentes differ from pyroclastic flows in that they are formed by the collapse of a lava dome, whereas pyroclastic flows are formed when the ash cloud collapses on itself. Do nuée ardentes deserve their own article? --The High Fin Sperm Whale (talk) 04:27, 16 October 2009 (UTC)
thread_title:  New article for nuée ardentes 

message: "a name for some pyroclastic flows." Can someone make that more specific please? I am doing a project on pyroclastic flows and surges.  —Preceding unsigned comment added by 124.182.30.125 (talk) 03:42, 14 March 2010 (UTC)
thread_title:  nuee ardentes 

message: What is missing from the article is an explanation of the mechanism at work in a pyroclastic flow which allows rock particles and heated gas to behave in association as they do.  In normal circumstances, hot gas in the atmosphere will flow straight up by convection, while rock particles, no matter how hot, will roll along the ground.  What is the mechanism which makes two components with very different relative densities act together? Peter Bell (talk) 23:05, 21 April 2010 (UTC)
thread_title:  Densities 

message: I removed the following:

I did a cursory examination of the Spanish article. It is shorter than the english article and does not appear to have additional info. However, I do not read Spanish. Can someone who can read Spanish please check this? -Arch dude (talk) 00:25, 23 February 2013 (UTC)
thread_title:  Improvement from the Spanish wiki? 

message: I am not an expert in this field, and this may be biasing my opinion, but the term "fully dilute" is used here without explanation and without links to any explanations.  I am completely uncertain as to its meaning - the common meaning of "dilute" indicates it isn't thick with pyroclast, but what does it mean to be "fully" dilute as opposed to "partially" dilute (if such a thing even exists)?  Non-experts (like me) might have difficulty with this.  73.206.173.11 (talk) 14:03, 11 October 2016 (UTC)
thread_title:  "Fully Dilute" 

message: I would like to propose major edits and combine this article with the article on [surges].
Currently, research on the topic uses the term pyroclastic density current rather than flow or surge. This is due to the understanding that a flow and a surge represent two ends on spectrum of flow regime (ie dilute and turbulent or dense and granular) but a single PDC can span multiple flow regimes. A surge can become a flow over time and a flow can become a surge etc. Hutvh (talk) 23:18, 14 August 2020 (UTC)
thread_title:  Combine with pyroclastic surge into one article on pyroclastic density currents?