Dispersal index (Volcanology 🌋)

Dispersal index is a parameter in volcanology. The dispersal index D {\displaystyle D} was defined by George P. L. Walker in 1973 as the surface area covered by an ash or tephra fall, where the thickness is equal or more than 1/100 of the thickness of the fall at the vent. An eruption with a low dispersal index leaves most of its products close to the vent, forming a cone; an ...

https://en.wikipedia.org/wiki/Dispersal_index

#DispersalIndex #Tephra #Volcanology

SciTech Chronicles. . . . . . . . .Jan 30, 2025

https://bit.ly/stc013025

#Ice Volcanism #Zavaritskii #sulfur #tephra #OSIRIS-REx #nucelobases #carbonate #phosphorus #boron #Zagros #Neotethys #Mesopotamia #Arabian #Eurasia #IO #Juno #JIRAM #gravitational #Tidal #Bioprinting #open-source #bioprinter #Printess #DIW #MM3D

Lapilli (Petrology 💎)

Lapilli is a size classification of tephra, which is material that falls out of the air during a volcanic eruption or during some meteorite impacts. Lapilli is Latin for "little stones". By definition lapilli range from 2 to 64 mm in diameter. A pyroclastic particle greater than 64 mm in diameter is known as a volcanic bomb when molten, or a volcanic block when solid. Pyroclastic material...

https://en.wikipedia.org/wiki/Lapilli

#Lapilli #Tephra #Petrology #VolcanicRocks

#Today a bit early for #ThickTrunkTuesday and #TinyTreeTuesday

A rescue collected from a gravel access road in a gravel pit high in the Cascades. A then stunted growth Pinus Contorta (Lodgepole Pine) that had been run over and was destined for the plow or wholesale removal as the gravel operation proceeded.

Dug up with a copious amount of native cinder around it and used nothing else for soil than that cinder…unsorted or screened to remove fines…just as was.

It has doubled in height in 3 years and gained an inch in the trunk girth. Needles are much longer now as the growing conditions much less harsh.

Time to make some decisions about future direction for this tree.

Likely into a large-ish pot to begin refinement:drop needle size back to scale.

#Bonsai #MakeGoodChoices
#Cinder #Tephra

Differential weathering of volcanic tuff at The Pinnacles area at Crater Lake. Mazama Ash deposits hundreds of meters in thickness have slightly different secondary mineralization and some have cap stones atop the spires that stand in relief…slightly shielding the weakly altered tuff below them.

Although an apron of ash deposits flank the volcano in all directions, this is the only place such deposits have formed in such dramatic display.

#Oregon #CraterLake #PNW #Volcano #Tephra #Ashfall #Tuff