GO HERE for info about specific isotopes, their abundances, and uses of unstable (radioactive) isotopes:
http://ie.lbl.gov/education/isotopes.htm
A few suggested isotopes: 210Pb (lead-coral growth), 13C (Seuss effect, diets, plant communities, food
chains), 14C (dating, Seuss effect), 2H (latitudes, tracers), 18O (glacial periods, temperature, latitude), 13C2 18
H- O “signatures” (geographic locations, migration), 224 Ra (radium, used to detect water input from
land ice into Antarctic seawater-email me for link), 15N (studying nitrogen fixation by different
organisms, nutritional state of rhinos and moose, food chains) , 33S and 34S versus 32S (sulfur isotopes
detecting ancient life in 3 billion year old rocks).
Email me if you have questions. Use your own words in your paragraphs. Do NOT duplicate work
please.
Some Links:
CSI Hair and H isotopes:
http://www.time.com/time/health/article/0,8599,1720520,00.html
18Oxygen and groundwater:
https://gsa.confex.com/gsa/2012AM/webprogrampreliminary/Paper211217.html
Tracing lead pollution
http://www.sciencedirect.com/science/article/pii/S0160412007001985
Monarch migration: Better migration through chemistry…18O/16O again
http://whyfiles.org/083isotope/index.html
Deuterium and latitude:
http://www.fort.usgs.gov/resources/spotlight/shorebird_isotopes/isotopes_deuterium.asp
Another Hydrogen example
http://www.fort.usgs.gov/resources/research_briefs/bat_isotopes.asp see with this
http://www.fort.usgs.gov/resources/spotlight/shorebird_isotopes/isotopes_deuterium.asp
Isotope signatures:
http://www.fort.usgs.gov/resources/spotlight/shorebird_isotopes/isotopes_howtheywork.asp
http://www.fort.usgs.gov/resources/spotlight/shorebird_isotopes/
Migratory birds:
http://www.fort.usgs.gov/resources/spotlight/shorebird_isotopes/isotopes_prelimdata.asp
Dolphin populations:
http://www.fort.usgs.gov/Products/Publications/22917/22917.pdf
List of isotope students on salmon, bear, dolphins, etc.
http://www.fort.usgs.gov/Research/research_tasks.asp?TaskID=2402
Lead in corals;
http://oceanexplorer.noaa.gov/edu/learning/player/lesson15/l15_la1.html
Pb-210 Coral growth rate half-life 22 years
C-13 and C-14 depletion as indication of fossil fuel contrib. to atmospheric C)2
http://environment.newscientist.com/channel/earth/climate-change/dn11638
Tracking Monarchs -H-2 Deuterium ratios used to trace monarch origins. Hotter  less D2O/H2O
Isotopes .. better migration through chemistry
http://whyfiles.org/083isotope/2.html
http://monarchwatch.org/class/studproj/hiso.htm
O-18 near equator, O-16 lighter carried to poles. Used to determine temperature moisture during
human evolution. Different ratio in transpired and surface water
http://earthobservatory.nasa.gov/Features/Paleoclimatology_OxygenBalance/oxygen_balance.php
http://climate.nasa.gov/
C-4 and C-3 plants have different C isotope signatures Used to determine diet in early humans and other
fossils
Nitrogen isotopes – used to detect starvation in rhinos, Isle Royal moose
http://ie.lbl.gov/education/isotopes.htm
CSEE Interactive Page – must include
Isotopes Project Home Page http://ie.lbl.gov/ip.html
Excess Ra used to detect terriginous input to ocean water around icebergs
Science 317, 478 (2007);
Kenneth L. Smith, Jr., et al.
Biological Enrichment in the Weddell Sea
Free-Drifting Icebergs: Hot Spots of Chemical and Biological Enrichment in the Weddell
Sea
Excess 224Ra (that fraction not supported
by ambient parent isotopes) was chosen as an
unambiguous terrigenous input. Because the only
viable source of excess 224Ra is the decay of
228Th
associated with terrigenous particles, the
enrichment must indicate local input of ice-rafted
detritus into the surrounding surface waters (typically
<10 m depth) from meltwater. The seasurface
layer in areas proximal to both icebergs
was enriched in excess 224Ra when compared
with deeper mixed-layer samples (30 to 80 m
depth) that were at or below the detection limit
(Fig. 2, E and F), precluding a deep upwelled
source of enrichment. Surface enrichments decreased
with increasing distance from the icebergs.
The highest excess 224Ra enrichment [5.0
disintegrations per minute (dpm) m–3] was observed
in water samples collected in brash ice
broken off and immediately adjacent to iceberg
W-86 (Fig. 2E).
STABLE ISOTOPES FOR DUMMIES-good stuff!
http://archaeology.about.com/b/2006/10/24/stable-isotopes-for-dummies.htm
http://archaeology.about.com/od/stableisotopes/a/si_intro.htm
New Applications of Stable Isotope Research
Since 1977, applications of stable isotope analysis have exploded in number and breadth, using
the stable isotopes ratios of the light elements hydrogen, carbon, nitrogen, oxygen and sulfur in
human and animal bone (collagen and apatite), tooth enamel and hair, as well as in pottery
residues (baked onto the surface or absorbed into the ceramic wall) to determine diets and water
sources. Light stable isotope ratios (usually of carbon and nitrogen) have been used to investigate
such dietary components as marine creatures (e.g. seals, fish and shellfish), various domesticated
plants such as maize and millet; cattle dairying (milk residues in pottery), and mother’s milk (age
of weaning, detected in the tooth row). Dietary studies have been done on hominins from the
present day to our ancient ancestors Homo habilis and the Australopithecines.
Other isotopic research has focused on the geographic origins of things. Various stable isotope
ratios in combination, sometimes including the isotopes of heavy elements like strontium and
lead, have been used to determine whether the residents of ancient cities were immigrants or
were born locally; to trace the origins of poached ivory and rhino horn to break up smuggling
rings; and to determine the agricultural origins of cocaine, heroin, and the cotton fiber used to
make fake $100 bills. The latest wrinkle involves the potential use of hydrogen and oxygen
isotopes in hair to determine where a person has been lately, by comparing the measurements
with an international database for rainfall and local water supplies.
Another example of isotopic fractionation that has a useful application involves rain, which
contains the stable hydrogen isotopes 1H and 2H (deuterium) and the oxygen isotopes 16O and
18
O. Water evaporates in large quantities at the equator and the water vapor disperses to the north
and south. As the H2O falls back to earth, the heavy isotopes rain out first. By the time it falls as
snow at the poles, the moisture is severely depleted in the heavy isotopes of hydrogen and
oxygen. The global distribution of these isotopes in rain (and tap water) can be mapped and the
origins of the consumers can be determined by isotopic analysis of hair. (Watch our for
skinheads arriving from the Axis of Evil!)
Pass the Sulfur, Please
Carbon and sulfur isotopic signatures provide the main evidence for the identification of the
earliest life on Earth. Details in the signatures of the several sulfur isotopes can now be used to
track metabolism. It was previously suggested that a large fractionation in the 34S versus 32S
isotopes implies that sulfate-reducing bacteria were present in rocks dated to about 3.5 billion
years ago. Philippot et al. (p. 1534; see the Perspective by Thamdrup), making use of 33S data,
show these rocks record the presence of organisms that metabolized and disproportionated
elemental sulfur. Several such organisms are present near the base of the phylogenetic tree.
This Week in SCIENCE
September 14 2007, 317 (5844) http://www.sciencemag.org/content/vol317/issue5844/twis.dtl
http://whyfiles.org/083isotope/3.html
An Airy Meal
The fixation of atmospheric nitrogen into ammonia that is
essential to human nutrition and global ecosystems is
performed by free-living bacteria and by symbionts in plant root
nodules. Lechene et al. (p. 1563; see the Perspective by
Kuypers), using multi-isotope imaging mass spectrometry with
15
the stable isotope of N, measured nitrogen fixation by symbiotic bacteria. They traced the utilization of
fixed nitrogen, in this case by animal rather than by plant host cells.
CREDIT: LECHENE ET AL.
How Stable Isotopes Work: Creating a “Signature”
http://www.fort.usgs.gov/resources/spotlight/shorebird_isotopes/isotopes_howtheywork.
asp
Isotopes are forms of a chemical element that have different numbers of neutrons and therefore a
different atomic mass. Stable isotopes are those that do not decay with time, and include isotopes
of hydrogen, oxygen, nitrogen, carbon, and sulfur. The power of stable isotopes for the study of
migratory birds hinges on two important facts.
First, the quantity of
found in natural
according to wellRatios of deuterium,
proportion to the
annual precipitation,
variations
across the globe.
isotopes, or isotopic ratios,
environments varies spatially
defined natural processes.
for example, vary in
temperature and quantity of
resulting in well-mapped
corresponding to latitude
Second, the isotopic
ratios in a geographic area
are reflected in the
local food chains. Hence, an
animal’s tissues
reflect the isotopic ratios of
its foods (such as plant material or insects), which in turn reflect isotopic ratios in the local water
and soils. A bird that migrates across geologic areas with large isotopic gradients, such as South
America, will exhibit different isotopic concentrations in its various body tissues. The turnover
rate of the isotopes differs among tissues; e.g., carbon isotopes have a turnover rate of a few days
in liver tissue, a few weeks in muscle and blood, and up to six months in bone collagen. Feathers
are unique, however, in that they grow in a very short time and then become metabolically inert.
Consequently, the isotopic content of a feather reflects the bird’s diet—and by extension, the
area where the feather developed—during the short period of time when the feather was grown.
Shorebirds that breed in the Arctic and winter in South America, for example, complete their
molt of flight feathers just before spring migration. Thus, isotopic ratios, or “signatures,” in the
flight feathers of an adult bird captured during migration or on breeding grounds will correspond
to those of the bird’s previous non-breeding area.
The cooperative study recently initiated between the USGS and partners in other countries will
evaluate (1) variation in isotopic signatures across the non-breeding range and (2) the use of
these signatures to identify linkages to specific migration corridors and breeding areas.
Google “environmental isotopes”, or go to Science News Daily or other reputable websites to find
isotopes.