Including Original "Paul H. Letters" Copyright © 1996-2024 Paul V. Heinrich / website © 1996-2024 Dirk Ross - All rights reserved.



Saturday, 20 July 2019

Moonrise - Washington Post Podcast Series 20JUL2019

 Moonrise - Washington Post Podcast Series

Moonrise - Washington Post Podcast Series

Yours,

Paul H.

Friday, 19 July 2019

Meteorite collections and researchers after the Brazil’s National Museum inferno 19JUL2019

 Meteorite collections and researchers after the Brazil’s National Museum inferno

The below article mentions the fate of meteorite collections and misfortunes
of meteorite researchers after flames consumed Brazil's National Museum.

The battle to rebuild centuries of science after an epic inferno
Nearly a year after flames consumed Brazil's National Museum
in Rio de Janeiro, researchers are struggling to revive their work
and resume their lives. by Emiliano Rodriguez Mega, Nature news
https://www.nature.com/articles/d41586-019-02141-2

Yours,

Paul H.

Saturday, 13 July 2019

Coastal Chevrons and Boulders – Room for Misinterpretation 13JUL2019

Coastal Chevrons and Boulders – Room for Misinterpretation

A paper worth reading is:

Spiske, M., Garcia Garcia, A.M., Tsukamoto, S. and Schmidt, V.,
High energy inundation events versus long term coastal
processes room for misinterpretation. Sedimentology.
https://onlinelibrary.wiley.com/doi/abs/10.1111/sed.12524


Spiske et al. (2019) discuss the controversy concerning the
origin of two coastal features, coastal chevrons (large
parabolic sand bodies) and coastal boulders. Because
of their large clast size, the coastal boulders are often
used as indicators of prehistoric tsunamis and storms.
Coastal chevrons are often attributed to either (mega)
tsunami, possibly caused by oceanic impacts, or to
MIS 5 "superstorms" as in case of the Bahamas and
Bermuda.


What I have not seen anyone discuss in the controversy
about coastal chevrons and coastal boulders is what is
known in geomorphology as the principle of equifinality,
in which different starting points for a given geomorphic
system results in similar end states. In simpler English,
equifinality postulates that similar landforms might arise
as a result of quite different sets of geologic and / or
geomorphic processes and histories. According to this
principle, a person might suggest that it is possible
coastal chevrons and coastal boulders can be produced
by both high energy inundation events versus long term
coastal processes. As a result, such features are not an
unique indicator of either a specific event or process.
Even in case of high energy inundation events (tsunamis,
"superstorms," and storms), it might be very difficult
to distinguish the specific type of event that created
a specific set of coastal chevrons and coastal boulders.


Some equifinality papers

Beven, K., 1996. 12 Equifinality and Uncertainty in
Geomorphological Modelling. In The Scientific Nature
of Geomorphology: Proceedings of the 27th Binghamton
Symposium in Geomorphology, Held 27-29 September,
1996 (Vol. 27, p. 289). John Wiley & Sons.

Beven, K., 2006. A manifesto for the equifinality thesis.
Journal of hydrology, 320(1-2), pp.18-36.

Phillips, J., 1997. Simplexity and the reinvention of
equifinality. Geographical Analysis, 29(1), pp.1-15.

A superstorm reference.

Hearty, P.J. and Tormey, B.R., 2017. Sea-level change and
superstorms; geologic evidence from the last interglacial
(MIS 5e) in the Bahamas and Bermuda offers ominous
prospects for a warming Earth. Marine Geology, 390,
pp.347-365

In other news, my family is hunkered down with our natural
gas standby generator on what passes for "high," ground in
Louisiana and prepared for Hurricane Barry. Nothing to do
now but listen to news and read a book and wait for it.

Yours,

Paul H.