tag:blogger.com,1999:blog-3319786799012800176.post8842852119454829898..comments2023-10-13T03:51:03.655-04:00Comments on Magma Cum Laude: Watch your step: Field work on lava domesJessica Ballhttp://www.blogger.com/profile/13117925212295349320noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-3319786799012800176.post-58062949858327597512010-03-08T13:58:30.466-05:002010-03-08T13:58:30.466-05:00Hi Jessica, I'm glad the trip to Guate went OK...Hi Jessica, I'm glad the trip to Guate went OK. Sorry that I couldn't go with your group but I had the meetings and workshops at the other volcano (Fuego). I'm still here enjoying (?) Fuego's eruptiontions.<br />Your comment on whether Santiaguito's eruptions are "vulcanian" or not caught my attention, because this debate seems endles and never the less it is very interesting and important if you want to figure out something about the eruption mechanism. Some vulcanologists even call some of the eruptions at Santiaguito "strombolian". In any case I think the spread of eruption styles at Santiaguito make's it hard to cast all in a single type, so maybe they should have their own type. I've seen many eruptions at Santiaguito that send meter-sized blocks to hundreds of meters from the vent, and eruptions that produce a lot of ash... so if I had to choose a name for those, I'd ask if I can use my own name: "Santiaguitoan eruption", but if that's not allowed, maybe I'd choose vulcanian. Now, what is a vulcanian eruption anyway? Do we defined it following Walker's 1973 F-D parameter field clasification?<br />Or do we call vulcanian all that looks ashy, impulsive, loud, etc... I would prefere to classify them based on an eruptive mechanism model, but that would make them more difficult to classify because you'd have to infer the mechanism from the observation, rather than directly calling something "vulcanian" or whatever just from the observation. This to me is not very clear and I think there should be some discussion on a vulcanologica forum (maybe IAVCEI or AGU) to clarify this.<br />Regarding the other comment you posted on Santa María's internal structure, its just amazing to have such a good exposure there. Although from a distance it seems like a perfect layered sequence there is a lot of complexity in it, and I'm sure, a lot that could still be learned. I had to spend endless days drilling and sampling that sequence, hoping that Santa María wouldn't burry me in debris. Probably the most interesting things we found out was the age of the sequence... from around 100 ka to 30 ka. So maybe there was a big pause before the 1902 eruption.<br />I'll be waiting to see more pictures and hear more stories about your trip, and I wish you luck with your research.<br />Saludos!Rudiger Escobar Wolfhttps://www.blogger.com/profile/07513617102198248588noreply@blogger.com