Communications Earth & Environment,
Год журнала:
2023,
Номер
4(1)
Опубликована: Июль 25, 2023
Abstract
Climate
warming
threatens
to
destabilize
vast
northern
permafrost
areas,
potentially
releasing
large
quantities
of
organic
carbon
that
could
further
disrupt
the
climate.
Here
we
synthesize
paleorecords
past
permafrost-carbon
dynamics
contextualize
future
stability
and
feedbacks.
We
identify
key
landscape
differences
between
last
deglaciation
today
influence
response
atmospheric
warming,
as
well
landscape-level
limit
subsequent
uptake.
show
current
magnitude
thaw
has
not
yet
exceeded
previous
deglaciations,
but
release
potential
exert
a
strong
feedback
on
Arctic
climate
temperatures
exceed
those
Pleistocene.
Better
constraints
extent
subsea
its
pool,
from
range
processes,
including
blowout
craters
megaslumps,
are
needed
help
quantify
permafrost-carbon-climate
Annual Review of Earth and Planetary Sciences,
Год журнала:
2023,
Номер
51(1), С. 611 - 641
Опубликована: Март 1, 2023
Carbonate
minerals
contain
stable
isotopes
of
carbon
and
oxygen
with
different
masses
whose
abundances
bond
arrangement
are
governed
by
thermodynamics.
The
clumped
isotopic
value
Δi
is
a
measure
the
temperature-dependent
preference
heavy
C
O
to
clump,
or
near
each
other,
rather
than
light
in
carbonate
phase.
isotope
thermometry
uses
values
measured
mass
spectrometry
(Δ47,
Δ48)
laser
spectroscopy
(Δ638)
reconstruct
mineral
growth
temperature
surface
subsurface
environments
independent
parent
water
composition.
Two
decades
analytical
theoretical
development
have
produced
mature
proxy
that
can
estimate
formation
temperatures
from
0.5
1,100°C,
up
1–2°C
external
precision
(2
standard
error
mean).
Alteration
primary
environmental
fluid-mediated
solid-state
reactions
and/or
reflect
nonequilibrium
fractionations
reveal
diagenetic
history
mineralization
processes.
has
contributed
significantly
geological
biological
sciences,
it
poised
advance
understanding
Earth's
climate
system,
crustal
processes,
minerals.
▪Clumped
record
robust
fluid
compositions
ancient
Earth
environments.▪Mature
methods
enable
Δ47,
Δ48,
Δ638
measurements
address
diverse
questions
sciences.▪These
marine
terrestrial
paleoenvironment
paleoclimate,
tectonics,
deformation,
hydrothermal,
studies.
Paleoceanography and Paleoclimatology,
Год журнала:
2023,
Номер
38(10)
Опубликована: Сен. 28, 2023
Abstract
Foraminiferal
isotopes
are
widely
used
to
study
past
oceans,
with
different
species
recording
conditions
at
depths.
Their
δ
18
O
values
record
both
seawater
oxygen‐18
and
temperature
according
species‐specific
fractionation
factors,
while
their
Δ
47
signatures
likely
depend
only
on
temperature.
We
describe
an
open‐source
framework
collect/combine
data
relevant
foraminiferal
isotopes,
by
constraining
factors
(
α
)
based
culture
experiments,
stratified
plankton
tows
or
core‐top
sediments;
compiling
tow
constraints
living
depths
for
planktic
species;
extracting
temperature,
O,
chemistry
from
existing
databases
any
latitude,
longitude,
depth‐range;
inferring
calcification
temperatures
the
above
data.
find
that
although
differs
between
species,
its
sensitivity
remains
indistinguishable
inorganic
calcite.
Based
>
2,600
observations
we
show
that,
most
consistent
over
expected
depths,
a
sizable
minority
(12%–24%)
have
heavier‐than‐predicted
best
explained
in
deeper
waters.
use
this
revisit
three
recent
calibration
studies
of
planktic/benthic
foraminifera,
confirming
varies
systematically
oxygen‐18‐derived
estimates,
even
samples
whose
disagrees
assumed
climatological
conditions,
demonstrating
excellent
agreement
foraminifera
modern,
largely
calibrations.
Benthic
remain
ambiguous:
modern
benthic
appear
offset
ones,
yet
applying
equilibrium
Cenozoic
foraminifer
Meckler
et
al.
(2022,
https://doi.org/10.1126/science.abk0604
reconciles
it
O‐derived
temperatures,
discrete
/δ
discrepancies
persisting
Late
Paleocene/Eocene/Plio‐Pleistocene.
Communications Earth & Environment,
Год журнала:
2023,
Номер
4(1)
Опубликована: Июль 25, 2023
Abstract
Climate
warming
threatens
to
destabilize
vast
northern
permafrost
areas,
potentially
releasing
large
quantities
of
organic
carbon
that
could
further
disrupt
the
climate.
Here
we
synthesize
paleorecords
past
permafrost-carbon
dynamics
contextualize
future
stability
and
feedbacks.
We
identify
key
landscape
differences
between
last
deglaciation
today
influence
response
atmospheric
warming,
as
well
landscape-level
limit
subsequent
uptake.
show
current
magnitude
thaw
has
not
yet
exceeded
previous
deglaciations,
but
release
potential
exert
a
strong
feedback
on
Arctic
climate
temperatures
exceed
those
Pleistocene.
Better
constraints
extent
subsea
its
pool,
from
range
processes,
including
blowout
craters
megaslumps,
are
needed
help
quantify
permafrost-carbon-climate
