Davin News Server

On Sat, 22 Feb 2025 12:49:09 -0800
Alan <nuh-uh@nope.com> wrote:

> On 2025-02-22 12:45, Mercy-a-lago wrote:
> > On Sat, 22 Feb 2025 12:44:01 -0800
> > Alan <nuh-uh@nope.com> wrote:
> >  =20
> >> On 2025-02-22 12:29, Mercy-a-lago wrote: =20
> >>> On Sat, 22 Feb 2025 15:18:37 -0500
> >>> Chris Ahlstrom <OFeem1987@teleworm.us> wrote:
> >>>     =20
> >>>> Mercy-a-lago wrote this post while blinking in Morse code:
> >>>>    =20
> >>>>> On Sat, 22 Feb 2025 11:57:41 -0800
> >>>>> Alan <nuh-uh@nope.com> wrote:
> >>>>>       =20
> >>>>>> On 2025-02-22 09:14, tye syding wrote: =20
> >>>>>>> On Fri, 21 Feb 2025 18:29:05 -0800
> >>>>>>> Alan <nuh-uh@nope.com> wrote:
> >>>>>>>          =20
> >>>>>>>> Do you supposed that when sea levels rise =20
> >>>>>>>
> >>>>>>>
> >>>>>>> Can you predict when that is going to happen?
> >>>>>>>          =20
> >>>>>>
> >>>>>> It is happening right now. =20
> >>>>>
> >>>>> 1/8th of an inch per year =3D normal glacial melt. =20
> >>>>
> >>>> Are you implying that the 1/8 rise then falls 1/8 in a yearly
> >>>> cycle? =20
> >>>
> >>> That has occurred, largely due to thermal expansion on the sea
> >>> floor =3D thermal vents, plate boundaries, volcanism.
> >>>
> >>> Active periods see a rise, then subsidence to normal.
> >>>
> >>> Glacial melt is a longer term slow rise.
> >>>     =20
> >>
> >> Where are you getting your ideas from, doofus? =20
> >=20
> > https://oceanservice.noaa.gov/facts/sealevel.html
> >    =20
> >> "Active periods" when referring to "thermal vents, plate
> >> boundaries, volcanism"? =20
>  >>>> Those are all continually occurring. There aren't "active
>  >>>> periods" =20
> >> and "inactive periods". =20
> >=20
> > Wrong!
> >=20
> > "Just as the surface of the Earth is not flat, the surface of the
> > ocean is also not flat=E2=80=94in other words, the sea surface is not
> > changing at the same rate globally. Sea level rise at specific
> > locations may be more or less than the global average due to many
> > local factors: subsidence, upstream flood control, erosion,
> > regional ocean currents, variations in land height, and whether the
> > land is still rebounding from the compressive weight of Ice Age
> > glaciers." =20
>=20
> Where does it say anything about "active periods" of ANYTHING, doofus?
>=20
> You were talking about glacial melt and for some incomprehensible
> reason were trying to claim it was due to an "active period" of
> "thermal vents, plate boundaries, volcanism"


https://earthsky.org/earth/volcano-under-pine-island-glacier-worlds-fastest=
-melting/

By tracing the glacial meltwater produced by the CDW, the researchers
discovered a volcanic signal that stood out in their data. The helium
measurements utilized were expressed by the percent deviation of the
observed data from the atmospheric ratio. For the observed CDW in the
Weddell Sea, this deviation was 10.2 percent. In the Ross and Amundsen
Seas, it was 10.9 percent. However, HE-3 values gathered by the team
during expeditions to the Pine Island Bay in 2007 and 2014 differed
from the historical data.

For this data, the percent deviation was considerably higher at 12.3 percen=
t, with the highest values being near the strongest meltwater outflow from =
the PIG=E2=80=99s front. Additionally, these high helium values coincided w=
ith raised neon concentrations, which are usually an indication of melted g=
lacial ice. The helium was also not uniformly distributed. This suggests it=
 originated from a distinct meltwater source and not from across the PIG=E2=
=80=99s entire front.

With this knowledge in hand, the team of scientists endeavored to
identify the source of the HE-3 production. The Earth=E2=80=99s mantle is t=
he
largest source of HE-3, although it is also produced in the atmosphere
and during past atmospheric tests of nuclear weapons through tritium
decay. These two sources, however, could only account for 0.2 percent
of the 2014 data.


The researchers then considered another source: a volcano beneath the PIG i=
tself, where He-3 escapes from the mantle in a process known as magma degas=
sing. The He-3 could be transported by glacial meltwater to the PIG=E2=80=
=99s grounding line, where the ice meets the underlying bedrock. At this li=
ne, the ice shifts due to the ocean tides, allowing the meltwater and the H=
e-3 to be discharged into the ocean.

After identifying a subglacial volcano as the most likely source of the ele=
vated He-3 levels near the PIG=E2=80=99s front, the scientists next calcula=
ted the heat released by the volcano in joules per kilogram of sea water at=
 the front of the glacier. It turned out that the heat given off by the vol=
cano constitutes a very small fraction of the overall mass loss of the PIG =
compared to the CDW, according to Loose.

In total, the volcanic heat was 32 =C2=B1 12 joules kg-1, while the heat co=
ntent of the CDW was much larger at 12 kilojoules kg-1. Nevertheless, if th=
e volcanic heat is intermittent and/or concentrated over a small surface ar=
ea, it could still have an impact on the overall stability of the PIG by ch=
anging its subsurface conditions, said Loose. There is also the possibility=
 that the continued melting of the PIG could lessen the pressure and weight=
 on the volcano, spurring more volcanism and subsequent melting.

https://www.nsf.gov/news/seismic-study-reveals-key-reason-patagonia-rising

Scientists at Washington University in St. Louis, led by seismologist Dougl=
as Wiens, recently completed one of the first seismic studies of the Patago=
nian Andes. In the journal Geophysical Research Letters, they describe and =
map out local subsurface dynamics.

"Variations in the size of glaciers as they grow and shrink, combined with =
the mantle structure we've imaged in this study, are driving rapid and spat=
ially variable uplift in this region," said Hannah Mark of the Woods Hole O=
ceanographic Institution, the first author of the publication.

The seismic data Mark and Wiens analyzed reveal that a gap in the down-goin=
g tectonic plate about 60 miles beneath Patagonia has enabled hotter, less =
viscous mantle material to flow underneath South America.

Above this gap, the icefields have been shrinking, removing weight that pre=
viously caused the continent to flex downward. The scientists found very lo=
w seismic velocity within and around the gap, as well as a thinning of the =
rigid lithosphere overlying the gap.

These mantle conditions are driving many of the recent changes observed
in Patagonia, including the rapid uplift in certain areas once covered
by ice.

The ongoing movement of land -- known as glacial isostatic adjustment =E2=
=80=93 matters, among other reasons, because it affects predictions for sea=
 level rise under future climate warming scenarios.=20

Mark said that one of the most interesting things discovered in this study =
was that the hottest and least viscous parts of the mantle were found in th=
e region of the gap, or slab window, below the part of the Patagonia icefie=
lds that most recently opened up.