LIGHTNING NEWSPARKS - 40 Years of Science at Mount St. Helens Farming Changes Are Improving Cuba's Water - Eos.org
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VOL. 101 | NO. 5 40 Years of Science
MAY 2020
at Mount St. Helens
Farming Changes
Are Improving Cuba's Water
Coastal Wetlands
Save Millions of Dollars
NEW
SPARKS FOR
LIGHTNING
SCIENCE
FROM THE EDITOR
Editor in Chief
Heather Goss, AGU, Washington, D.C., USA; Eos_EIC@agu.org
Investigating the Spark AGU Staff
Vice President, Communications, Amy Storey
Marketing, and Media Relations
“T here’s a term in French that describes falling in love Editorial
Manager, News and Features Editor Caryl-Sue Micalizio
at first sight: coup de foudre,” said Yoav Yair. “Liter-
Science Editor Timothy Oleson
ally translated, it means ‘bolt of lightning.’” Yair is News and Features Writer Kimberly M. S. Cartier
the dean of the School of Sustainability at the Interdisciplinary News and Features Writer Jenessa Duncombe
Center Herzliya in Israel and Eos’s Science Adviser for AGU’s
Production & Design
Atmospheric and Space Electricity section. “This is how I felt
Manager, Production and Operations Faith A. Ishii
about atmospheric electricity when I started my master’s Senior Production Specialist Melissa A. Tribur
degree at Tel Aviv University back in the 1980s: instant fasci- Assistant Director, Design & Branding Beth Bagley
Senior Graphic Designer Valerie Friedman
nation, deep curiosity, and a desire to know more.”
Graphic Designer J. Henry Pereira
I was excited when Yair suggested that we cover lightning
in our May issue of Eos. As a magazine editor, I certainly think Marketing
you can’t beat the photography, but more than that, I was Director, Marketing, Branding & Advertising Jessica Latterman
Assistant Director, Marketing & Advertising Liz Zipse
intrigued by the number of questions that remain about this
phenomenon nearly all of us have grown up experiencing, watching from our windows as Advertising
storms roll in. “Lightning is indeed beautiful, dangerous, and multifaceted, and it hides a lot Display Advertising Dan Nicholas
and reveals a lot. And although it has been known to humanity for millennia—feared and wor- dnicholas@wiley.com
Recruitment Advertising Kristin McCarthy
shiped—we still don’t fully understand it,” explained Yair. kmccarthy@wiley.com
Chris Schultz of NASA’s Short-term Prediction Research and Transition Center assures me
we are living in a “second golden age” of lightning observations. In “Lightning Research Science Advisers
Flashes Forward” (p. 28), meteorologist Ashley Ravenscraft explains how she uses data recently Geomagnetism, Paleomagnetism, Julie Bowles
and Electromagnetism
made available to the National Weather Service from the Geostationary Lightning Mapper on Space Physics and Aeronomy Christina M. S. Cohen
board the GOES-R satellite (p. 5) that show the rate of lightning strikes in an area. She uses Cryosphere Ellyn Enderlin
these data—sometimes these data alone, when necessary—as a proxy to predict tornadoes Study of the Earth’s Deep Interior Edward J. Garnero
Geodesy Brian C. Gunter
and issue warnings to the nearby Huntsville, Ala., community. Like so many meteorologists, History of Geophysics Kristine C. Harper
she got into the field to save lives, and with this new information, she’s giving her neighbors Planetary Sciences Sarah M. Hörst
sometimes as long as 45 minutes to get to safety. Natural Hazards Michelle Hummel
Volcanology, Geochemistry, and Petrology Emily R. Johnson
“In recent decades, we have made tremendous progress and devised sophisticated ways to Societal Impacts and Policy Sciences Christine Kirchhoff
decipher lightning and its associated impacts on the atmosphere,” said Yair, “here on Earth Seismology Keith D. Koper
and also on other planets.” In “Planetary Lightning: Same Physics, Distant Worlds” (p. 22), Tectonophysics Jian Lin
Near-Surface Geophysics Juan Lorenzo
we take a trip through the solar system to investigate why lightning is pervasive on Jupiter,
Earth and Space Science Informatics Kirk Martinez
how Neptune and Uranus are similar in so many ways except in generating lightning, and, in Paleoceanography and Paleoclimatology Figen Mekik
this case and so many others, why Venus is just so weird. Mineral and Rock Physics Sébastien Merkel
Ocean Sciences Jerry L. Miller
Finally, where are all these lightning data when you need them? On page 18, learn about
Global Environmental Change Hansi Singh
WALDO—the Worldwide Archive of Low-frequency Data and Observations—in “Returning Education Eric M. Riggs
Lightning Data to the Cloud.” Morris Cohen, professor of electrical engineering at Georgia Hydrology Kerstin Stahl
Institute of Technology (and president-elect of AGU’s Atmospheric and Space Electricity sec- Tectonophysics Carol A. Stein
Atmospheric Sciences Mika Tosca
tion), and a colleague manage this database of radio measurements meant to facilitate research Nonlinear Geophysics Adrian Tuck
not only in lightning but also in space weather, terrestrial gamma rays, and gravity waves, Biogeosciences Merritt Turetsky
among other phenomena. Hydrology Adam S. Ward
Earth and Planetary Surface Processes Andrew C. Wilcox
“As our society becomes more technological, urban, [and] densely populated, and as our Atmospheric and Space Electricity Yoav Yair
climate is changing, we need to know what lightning will be like in the future,” said Yair. We GeoHealth Ben Zaitchik
hope this issue gives you some idea of how lightning affects us, as well as of the interdisci-
plinary nature of the exciting science questions it presents.
©2020. AGU. All Rights Reserved. Material in this issue may be photocopied by
individual scientists for research or classroom use. Permission is also granted
to use short quotes, figures, and tables for publication in scientific books and
journals. For permission for any other uses, contact the AGU Publications Office.
Eos (ISSN 0096-3941) is published monthly by AGU, 2000 Florida Ave., NW,
Washington, DC 20009, USA. Periodical Class postage paid at Washington, D.C.,
and at additional mailing offices. POSTMASTER: Send address changes to Member
Service Center, 2000 Florida Ave., NW, Washington, DC 20009, USA
Member Service Center: 8:00 a.m.–6:00 p.m. Eastern time; Tel: +1-202-462-6900;
Heather Goss, Editor in Chief Fax: +1-202-328-0566; Tel. orders in U.S.: 1-800-966-2481; service@agu.org.
Submit your article proposal or suggest a news story to Eos at bit.ly/Eos-proposal.
Views expressed in this publication do not necessarily reflect official positions
of AGU unless expressly stated.
SCIENCE NEWS By aGU // Eos.org 1
CONTENT
18 28
22 34
Features
18 Returning Lightning Data 28 Lightning Research Flashes
to the Cloud Forward
By Morris Cohen By Heather Goss
No longer lost among the Betamax tapes in a dusty A new wave of instruments is helping researchers make
warehouse, these low-frequency observations have a big leaps in their knowledge of the “big spark.”
new digital home.
34 Lessons from a Post-Eruption
22 Planetary Lightning: Same Landscape
Physics, Distant Worlds By Jon J. Major et al.
By Kimberly M. S. Cartier
Scientists have had 4 decades to watch the biophysical
Lightning is a powerful tool to learn about the complex responses to the cataclysmic eruption on Mount
environments around the solar system and beyond. St. Helens.
On the Cover
Brandon Morgan/Unsplash
2 Eos // May 2020
CONTENT
15 42
Columns
From the Editor AGU News
1 Investigating the Spark 41 The Future Needs Science. The U.S. Elections
Need You | STEM Supports 67% of U.S. Jobs
News
4 Speleothem Documents Belgium’s Historic Climate
Research Spotlight
5 Mapping Lightning Strikes from Space 42 How to Read Atmospheric History Written
6 Earth’s Skies Transmitted Signs of Life During in Flowstones
Lunar Eclipse 43 Investigating Rates of Microbial Methane Munching
8 Microbes Discovered Hanging Out in the Ocean’s in the Ocean | Missing Lakes Under Antarctic Ice
Crust Sheets
9 Researchers Quantify a Seeded Snowpack 44 Santa Ana Winds and Wildfires Influence
10 The Ecological Costs of Removing California’s Air Pollution | New Study Shifts Paradigm of Coastal
Offshore Oil Rigs Sediment Modeling
12 Could Wildfire Ash Feed the Ocean’s Tiniest 45 Solving the Global Nitrogen Imbalance
Life-Forms?
13 Coastal Wetlands Save $1.8 Million per Year Positions Available
for Each Square Kilometer
46 Current job openings in the Earth and space sciences
15 Sustainable Agriculture Reflected in Cuba’s
Water Quality
Postcards from the Field
Opinion 48 Researchers prepare to ski across a glacier in the
Canadian Rockies, carrying a ground-penetrating
16 Don’t @ Me: What Happened When Climate Skeptics
radar to measure ice thickness.
Misused My Work
AmericanGeophysicalUnion @AGU_Eos company/american-geophysical-union AGUvideos americangeophysicalunion americangeophysicalunion
SCIENCE NEWS BY AGU // Eos.org 3
NEWS
Speleothem Documents Belgium’s Historic Climate
D
eep in the south of Belgium, near the appeared in sig-
winding Lesse River, lies a cave rich nificantly higher
with history and geologic wonders. amounts in more
The Han-sur-Lesse cave system has long fas- recent samples,
cinated visitors, with its well-defined calcium hinting at anthro-
carbonate formations (speleothems) mar- pogenic pollution.
veled at for centuries. Trace elements
Recently, scientists from various Belgian also revealed more
institutions studied one of the cave’s fastest subtle properties
growing stalagmites, Proserpine, to learn about the cave and
more about the evolution of the region’s cli- the region’s past
mate. By analyzing such data as stable iso- climate. For exam-
topes and trace elements, the researchers ple, elevated levels
found clear evidence of increasingly dry con- of magnesium,
ditions and anthropogenic activity over the barium, and stron- Researchers analyze speleothems in Belgium’s Han-sur-Lesse cave system. Credit:
past 4 centuries. tium suggest high- Sophie Verheyden
er rates of prior
Tiny Clues from the Past calcite precipita-
Proserpine is formed by water dripping from tion in the modern
bedrock above the cave. Once the drip water drip waters. Prior calcite precipitation occurs Speleothems add a great
lands on the surface of the stalagmite, it when drier conditions and hotter tempera-
releases carbon dioxide and precipitates into tures cause water to percolate more slowly deal to the bigger picture
a mixture of calcium carbonate and any other through the bedrock, giving the water more of climate history.
minerals that hitched a ride on the way down time to precipitate calcite and pick up trace
through the limestone above. With a flat, elements before entering the cave.
2-square-meter face growing at roughly half Another, more obvious sign that the Bel-
a millimeter per year, this special stalagmite gian climate has gotten drier over time can
displays clearly distinct layers with seasonal be seen in the stalagmite layers themselves. researcher on the study, another way to mea-
variability, making it a perfect proxy to study Thicker layers are found in the Little Ice Age sure seasonality is by detecting invisible lay-
past climate. samples because rainfall levels and drip water ers in speleothems that reveal themselves
In a recent paper published in Climate of the precipitation on Proserpine were higher. through ultraviolet light, a phenomenon
Past, researchers analyzed three distinct sec- known as luminescence. Other methods, such
tions of Proserpine, labeling them P16, P17, Digging Deeper as measuring wiggles in amounts of phos-
and P20, according to the centuries they rep- One of the study’s most intriguing discover- phorus, can be used as well.
resent (bit.ly/stalagmite-seasons). Because ies was the stark contrast in trace elements Just like telescope engineers, scientists will
the stalagmite’s layers show a distinct sea- between the P16 and P17 samples. This continue to upgrade their paleoclimate tech-
sonal variability in chemical composition, the marked shift suggests a change in vegetation niques to peer deeper into the past. “This
researchers were able to make several conclu- cover, possibly introduced by l ate-17th- research is very difficult because there are a
sions about how Belgian climate and land use century farmers—but no historical records lot of things that can happen to the rainwater
have changed seasonally over many centuries. were found to independently confirm this before it reaches the stalagmite. Understand-
“Caves and speleothems are rather local hypothesis. What’s certain is that something ing all these processes requires a mixed
phenomena, but they can record patterns of abruptly affected the drip water’s path understanding of biological, geological,
regional climate quite accurately,” said Niels through the ground during this period. hydrological, and chemical processes,” de
de Winter, a postdoctoral researcher at Vrije In the words of the researchers, the change Winter emphasized.
Universiteit Brussel and one of the authors on itself “can serve as a valuable palaeoclimate Ian Fairchild, professor emeritus at the Uni-
the study. When added to paleoclimate data proxy.” Many speleothem studies take place versity of Birmingham in the United Kingdom
from such proxies as tree rings, ice cores, and over decadal to millennial scales, making and a longtime speleothem expert, said, “This
peat bog records, speleothems add a great these abrupt changes harder to resolve and looks to be a very well-executed study that
deal to the bigger picture of climate history. place in context. To get around this hurdle, makes excellent use of preserved h igh-
Their samples cover a much longer period of the researchers suggest sampling w ell- resolution information.” And although he
time than tree ring data, as well as a broader e xpressed seasonal speleothem layers at admitted that many speleothems can’t be stud-
range of environments than ice cores or peat “strategic places” and superimposing them ied in such detail, he noted that when they are,
bog records. over longer timescales. However, not all spe- “a powerful understanding can be revealed.”
De Winter and his colleagues used laser leothems have well-expressed layers.
spectroscopy to detect trace elements, among According to Sophie Verheyden, a postdoc-
the most important data found within spe toral researcher at the Royal Belgian Insti- By Christian Fogerty (@ChristianFoger1),
leothems. Some trace elements, like lead, tute of Natural Sciences in Brussels and a Science Writer
4 Eos // May 2020
NEWS
Mapping Lightning Strikes from Space
I
f lightning strikes anywhere in the Western
Hemisphere, odds are it has already been
detected and mapped by s atellite-bound
cameras orbiting some 35,000 kilometers
above Earth.
Lightning flashes are more typically
mapped from ground-based networks using
radio frequencies to generate precise data on
the order of meters (see “Lightning Research
Flashes Forward,” p. 28). However, ground-
based systems have a limited line of sight.
The view from a satellite does not, for exam-
ple, need to “account for things like tree lines
or city skylines or even just general dissipa-
tion over distance,” said Michael Peterson, an
atmospheric scientist at Los Alamos National
Laboratory in New Mexico.
The idea of using a satellite to detect light-
ning has been around since at least the 1980s,
but with the launch of the National Oceanic
and Atmospheric Administration’s (NOAA)
Geostationary Operational Environmental
Satellite–R Series (GOES-R) weather satel-
lites starting in 2016, researchers and fore-
casters have attained unprecedented amounts
of lightning data from the Geostationary Five minutes of lightning from the Geostationary Lightning Mapper show small areas of high lightning flash rates
Lightning Mapper (GLM) instruments (maximum of about 100 per minute) and a few very large flashes that cover thousands of square kilometers.
attached to the satellites. Credit: NOAA/NESDIS/Scott Rudlosky
An interdisciplinary team of researchers
now has developed a technique that can map
out the lightning flashes GLM detects across
the entire Western Hemisphere in real time. really challenging to even know what to do The researchers demonstrated that this
“It’s not only a matter of being able to see with those data,” he said. pace-based lightning mapping technique
s
more, but being able to see things com- The new technique reconstructs and spa- can distinguish the many tiny flashes of
pletely,” said Peterson, who was not involved tially maps the lightning flashes while retain- lightning within thunderstorm cores and the
in the study. large lightning flashes that are part of meso-
The new technique was reported in the scale storm systems.
Journal of Geophysical Research: Atmospheres
(bit.ly/GLM-images) and has been adapted Myriad Applications
for use by the U.S. National Weather Service
Adapting the technique The technique’s application for weather
(NWS). to work with the NWS forecasters was readily apparent and rapidly
developed over the course of a year to be used
Seeing Lightning More Completely systems required getting by NWS. The process required getting the
The GLM is essentially a video camera in the product to work with product to work with NWS operational dis-
space that captures lightning flashes across play systems, matching data formats, mak-
the Western Hemisphere at 500 frames per NWS operational display ing it timely, and not allowing it to fail,
second. “There’s very little dead time. No systems, matching data Bruning said. In adapting the tool for prac-
matter how rare the lightning flash is, you’re tical applications, “you find all the bugs that
probably going to see it,” Peterson said. formats, making it timely, you just ignore as a researcher in your code.”
But that deluge of data comes with a down- and not allowing it to fail. Using this technique, it would be possible
side. “You can’t send all that video data down to track the origin of so-called bolts from the
to the ground,” said Eric Bruning, an atmo- blue that occur without rain, said Chris
spheric scientist at Texas Tech University in Schultz, a research meteorologist at NASA’s
Lubbock and lead author on the study. Short-term Prediction Research and Transi-
Instead, the data are sent as pixels attached ing the quantitative physical measurements tion Center in Huntsville, Ala., and coauthor
to geolocation information that clustered into made by the GLM. “In a way, it’s just restoring on the study. Seeing the origin of the flash is
lightning flashes. “For a lot of users, it’s just the video nature of the camera,” Bruning said. important to anticipate future lightning and
SCIENCE NEWS BY AGU // Eos.org 5
NEWS
is not possible with traditional ground-based
lightning data. This capability is important
Earth’s Skies Transmitted Signs
for public safety because “the majority of
injuries and fatalities occur just before the
of Life During Lunar Eclipse
rain has started or just after the rain has
ended,” Schultz said.
“Right now the main users are [at] the
National Weather Service, and that’s mainly
because the instrument is brand-new to the
public,” said Schultz. He expects that as the
technology evolves and gets into the public’s
hands, it will become more widely used, like
radar is now.
“It is certainly useful to be used in real
time, but it’s not as useful as it could be,”
Peterson said. One major caveat with the
technique is that it relies on the data provided
by NOAA and assumes their veracity. “Unfor-
tunately, the algorithm is not perfect.”
Because of the complexity of the data, large
flashes of lightning are automatically split
into multiple flashes, explained Peterson. He
recently published a new processing system
to stitch these smaller flashes back together.
“Now, this isn’t a huge deal in terms of over-
all statistics. We’re talking 4% to 8% of all
lightning depending on what storm you’re
looking at.”
During a total lunar eclipse, the Moon travels first through the umbral (orange) and then the penumbral (red)
shadow of the Earth, becoming progressively darker and redder before returning to normal. This is a composite
of a sequence of images of the 21 January 2019 total lunar eclipse as seen in Austria. Credit: H. Raab, CC B
Y-SA
4.0 (bit.ly/ccbysa4-0)
L
ast year’s so-called super blood wolf “Exoplanets are truly alien worlds and typ-
moon gave astronomers the chance to ically have very different properties from the
measure the spectrum of Earth’s atmo- solar system planets,” said Eliza Kempton, an
sphere as if it were a transiting exoplanet, a assistant professor of astronomy at the Uni-
feat that is possible only during a total lunar versity of Maryland in College Park who was
eclipse. not involved with this research. “We must
“It’s a very fascinating thought to imagine first establish what the Earth and other solar
that the spectrum of Earth is always broad- system planets look like ‘as exoplanets’ to
cast to the outside,” said Matthias Mallonn, benchmark our understanding of the far more
a postdoctoral researcher at Leibniz Institute exotic extrasolar planets.”
for Astrophysics Potsdam in Germany. Mal-
Still, the latest study adds a powerful new lonn and other researchers on the project Lunar Eclipse Mimics a Transit
tool for scientists and forecasters studying typically hunt for faint spectral signals from One way that astronomers can measure the
lightning. The technique, which is available as the atmospheres of distant worlds, but the chemical composition of exoplanet atmo-
open-source software, also grants “the ability lunar eclipse let them look at Earth instead. spheres is called transmission spectroscopy,
to use lightning to monitor the climate and During the 21 January 2019 total lunar which captures starlight that has passed
also to even study storm processes in places eclipse, the researchers used one of the larg- through a planet’s atmosphere. The atmo-
where we don’t have the rich radar network est visible-light telescopes on Earth to mea- sphere imprints a chemical signature on the
that we have in the U.S.,” Bruning said. sure the spectrum of sunlight that had passed starlight that can reveal major components
“I think it’s important to keep that global through the top of Earth’s atmosphere. That like water, methane, or even metal oxides. So
perspective in mind,” he added. light bore signals from molecular oxygen and far, most of these measurements have been
water vapor and also sodium, potassium, and done for large, gaseous planets that orbit
calcium. This is the first time this method has close to their stars.
By Richard J. Sima (@richardsima), Science been used to spot those three elements in Future telescopes will allow similar mea-
Writer Earth’s atmosphere. surements of E arth-sized planets in the hab-
6 Eos // May 2020
NEWS
We must first establish Earth’s transmission spectrum showed
strong signals from molecular oxygen and
thing about it,” he said. “We would have to
wait another 10 years for the next generation
what the Earth and other from water, both important biosignatures. of g
round-based telescopes with much larger
solar system planets look Sodium, calcium, and potassium also
appeared in Earth’s transmission spectrum,
mirror sizes and much larger apertures.”
Some of those telescopes, such as the Euro-
like ‘as exoplanets’ to and all three elements have been detected pean Extremely Large Telescope and the
in the atmospheres of hot Jupiter exoplanets. Thirty Meter Telescope, are currently in
benchmark our These results were published in Astronomy development and are expected to play a cru-
understanding of the far and Astrophysics (bit.ly/eclipse-Earth-transit). cial role in detecting signs of life on exoplan-
“The entire exercise was not to learn ets, Mallonn said.
more exotic extrasolar something new about the Earth’s atmo- Moreover, molecular oxygen and water
planets. sphere,” Mallonn said, “but to prove the aren’t the most convincing of biosignatures.
technique and check out how well we can Methane, ozone, and a host of gases are more
actually get to the biosignature features, the suggestive of life. However, the most persua-
molecules that might be indicative of life.” sive biosignatures produce signals at longer
itable zones of their host stars, and the “Studies such as this one, which observe infrared wavelengths that are difficult to
researchers wanted first to test this out on solar system planets as if they were exoplan- measure beneath Earth’s atmosphere. The
Earth. Fortunately, the positions of the Sun, ets—i.e., using the same types of observa- atmosphere absorbs much of that light in
Earth, and Moon during a total lunar eclipse tional techniques and/or observing geome- what’s called a telluric spectrum.
mirror the geometric setup needed for this: try—are vital for our understanding of “In the infrared, the space telescopes have
the Sun as the distant star, the Earth as the exoplanet atmospheres,” Kempton said. the strong advantage of not being affected by
exoplanet, and the Moon as the f ar-off the telluric component of the spectrum,”
observer, Mallonn explained. Awaiting Future Telescopes Mallonn said. The James Webb Space Tele-
However, there is no telescope on the Mallonn acknowledged that a lunar eclipse scope is expected to fill that role.
Moon waiting to capture the transmitted isn’t a perfect analogue to what astronomers “It’s rather simple to see that there’s life
light. Instead, the team measured that light could expect to see from a transiting exo- on Earth,” he said. “If another civilization
after it reflected from Tycho Crater. That planet. During a total lunar eclipse, an living out there takes a spectrum of the Earth,
light then entered our atmosphere and was observer on the Moon would see the entire then [it’ll] actually see by our own biosigna-
observed by the Large Binocular Telescope Sun blocked by the Earth, but a transiting ture molecules that there is life…and I just
(LBT) over a roughly 4-hour period. After exoplanet blocks only a small fraction of its hope that in another 30 years or whenever,
accounting for the spectra of sunlight, the host star. The atmospheric signal from such we might be able to do a similar observation
lunar surface, and contamination from trav- an exoplanet would be much weaker than of another planet.”
eling to the telescope on the ground, the what the team observed for Earth, he said.
team was left with the signal as it appeared At the moment, “if we were in the situation
when the light passed through Earth’s where we found an E arth-sized planet around By Kimberly M. S. Cartier (@AstroKimCartier),
atmosphere. a Sun-like star, the LBT could hardly do any- Staff Writer
Nominate a Colleague
Successful nominations take time, but the honor of being selected
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Deadline extended to 1 June for all Honors and Awards
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SCIENCE NEWS BY AGU // Eos.org 7
NEWS
Microbes Discovered Hanging Out in the Ocean’s Crust
These [communities] can
basically be hanging out
for millions of years in a
very quiescent state.”
hydrothermal vents, said Edgcomb. But un-
like what she expected, the underground life
relied on both fixing chemicals for energy and
co-opting organic matter floating in the fluid.
Messenger RNA analysis revealed that the
microbes can recycle amino acids or lipids of
dead (or even living) matter. Steven D’Hondt,
a professor at the University of Rhode Island
Microbiologist Ginny Edgcomb (left) and Gaëtan Burgaud cultured fungal colonies from rock samples deep who was not involved with the research, said
within the seafloor. Credit: Tom Kleindinst/WHOI this “runs counter to standard assumptions
about subseafloor crustal life.”
“The readiness of that community to con-
sume organic matter suggests that it is met-
S
cientists have found evidence of active The latest research, published in the jour- abolically linked to the broader world (e.g.,
microbial communities living in the nal Nature, suggests that survival in the deep the ocean) via ocean circulation,” D’Hondt
oceanic crust hundreds of meters biosphere depends on underground fluid flow said.
beneath the seafloor, proving that life can (bit.ly/fluid-flow). As seawater entrains deep It’s unclear whether these results can
persevere under even the most extreme and in the crust, it travels through cracks in the apply to other areas of the ocean’s lower
remote conditions. rock, some microfine and others as large as, crust. The research team extracted cores
Rock cores drilled from an undersea moun- or even larger than, spaghetti noodles. The from the undersea mountain Atlantis Bank
tain in the Indian Ocean revealed that bacte- fluid likely carries organic matter from the where the lower crust is exposed at the ocean
ria, fungi, and single-celled organisms called bottom, which is unusual—normally, thou-
archaea live in cracks and fissures in the sands of meters of sediment would cover it.
dense rock of the ocean’s lower crust. The sci- The site gave the research team unprece-
entists discovered that the rock samples con- dented access to the lower crust, but future
tained biosignatures of life, including DNA research must confirm whether life is pos-
and lipid biomarkers, and messenger RNA sible with upper crust and bottom sediments
extractions showed that some of the cells still intact.
were actively dividing. The latest study shows that “life finds a
Beneath the soft sediments of the seafloor way,” said Jennifer Biddle, an associate pro-
sit layers of basaltic and gabbro rocks that fessor at the University of Delaware who did
make up the oceanic crust. Scientists know not take part in the study. Earth’s lower oce-
that life exists in seafloor sediments, but only anic crust could be an analogue of how life
one previous study in the Atlantic Ocean might survive on other planets, Biddle added.
probed the oceanic crust for signs of life (bit Edgcomb cautions that the biomass in the
.ly/crust-life). In the latest research, scien- A thin section of the rock core shows distinct minerals study was extremely low: The cells are just
tists recovered rock from 750 meters into the (colored) and a small cavity through which fluid may “barely eking out a living,” she said. Still,
lower crust and performed a host of labora- have flowed, delivering organic matter that fuels sub- “the lower ocean crust is one of the last fron-
tory tests in search of microbial activity. surface microorganisms. Credit: Frieder Klein/WHOI tiers of the exploration for life on Earth,”
“These [communities] can basically be Edgcomb said. “We have a better understand-
hanging out for millions of years in a very qui- ing that the lower crust does indeed host via-
escent state,” study author and associate sci- ble and, in some cases, active microbial
entist Virginia Edgcomb, from Woods Hole ocean, said Edgcomb, and the team found cells.”
Oceanographic Institution, said. “I’m sure signs of life clustered around these nutrient
even the active microbes are carrying on at a highways.
very slow rate relative to those near the sur- Many of the microorganisms match those By Jenessa Duncombe (@jrdscience), Staff
face, but nevertheless, they’re buzzing along.” observed in other extreme environments, like Writer
8 Eos // May 2020NEWS
Researchers Quantify a Seeded Snowpack
S
kiers are in their element the moment
temperatures start to fall—gear out,
tire chains at the ready, and eager for
the first snowflakes to float down from the
sky.
Snow season is a popular time in the west-
ern United States, but winter precipitation
does more than create a playground for out-
door enthusiasts. Winter snowpacks provide
much-needed water for arid and populated
Western states, and in a warming climate,
these snowpacks are at risk.
For almost 100 years, scientists have been
working on a way to seed clouds, forcing them
to drop their floating moisture. Seeding
works, but scientists have found it difficult to
quantify just how much precipitation is a
result of cloud-seeding events.
In a new study, scientists were able to mea-
sure the amount of snow generated from
cloud seeding over an area in western Idaho.
This work is an important step in under-
standing how effective cloud seeding might that significant precipitation was generated still-pressing question, which is whether or
produce much-needed water in the arid and from cloud seeding. not cloud seeding is an effective way of
mountainous West. The team traveled to Idaho’s Payette River increasing precipitation, and apply cloud
basin to measure precipitation resulting from research tools to try to effectively answer that
Coaxing Precipitation from Clouds three cloud-seeding events. Weather radar question,” said Gannet Hallar, director of the
Seeding clouds in mountainous regions, or tracked the generation and intensity of pre- Storm Peak Laboratory at the Desert Research
orographic cloud seeding, has the potential to cipitation while gauges on the ground mea- Institute in Steamboat Springs, Colo. She was
increase water storage in dry areas. During sured snowfall during three hour-long seed- not part of the new study.
orographic seeding, silver iodide (AgI) is ing sessions. Hallar said although the study was an
released from an airplane or flares. Tiny, impressive and carefully designed investiga-
supercooled water droplets in the atmosphere tion, “the limitation is that these are only
crystallize around the AgI droplets, eventually case studies.” She added that there are still
merging and becoming heavy enough to fall Seeding clouds in unanswered questions about how spatial and
out of the sky. temporal variables in the atmosphere affect
But the efficacy of artificially coaxing water mountainous regions has precipitation from cloud seeding.
out of the sky has been a mystery. “Despite the potential for increasing “It’s one thing to increase precipitation at
cloud seeding being conducted for almost a a given point; it’s another thing to increase
hundred years, we had difficulties quantifying water storage in dry areas. precipitation over a basin scale,” said Hallar.
how much water we can get out of these She noted that expanding the cloud-seeding
clouds,” said Katja Friedrich, an atmospheric research to another orographic area would be
scientist at the University of Colorado Boul- a logical next step in understanding how to
der and lead author of the paper in the Pro- Snow ranging from 0.05 to 0.3 millimeter create targeted precipitation. “There’s still
ceedings of the National Academy of Sciences of fell to the ground after the seeding events. quite a bit of research to be done,” she said.
the United States of America (bit .ly/seeding “In total, we generated water that’s equiva- Friedrich agreed with Hallar and said there
-snowfall). lent to 282 Olympic-sized swimming pools,” are a lot of unanswered questions.
Friedrich said the biggest problem is dis- said Friedrich. The team’s next steps include more scien-
tinguishing natural precipitation from that In addition to the measurements of snow, tific analyses of their data, including under-
generated from cloud seeding. In the past, Friedrich noted that her team learned how standing the water year with and without
scientists statistically compared the results the distributions of snow changed on the cloud seeding and how much of the water
of a cloud-seeding event to precipitation on basis of atmospheric conditions. For example, would get stored in stream and reservoir sys-
a nonseeding day. on the third day of seeding, high winds and tems.
turbulent conditions caused precipitation to
Denys Nevozhai
Measuring Snowfall spread out over a large area.
Friedrich said her team’s monitoring method “I think what is interesting about this By Sarah Derouin (@Sarah_Derouin), Science
allowed them to see unambiguous evidence study is that they were able to take a very Writer
SCIENCE NEWS BY AGU // Eos.org 9NEWS
The Ecological Costs of Removing
California’s Offshore Oil Rigs
plugging and abandoning the wells. And then
conversations will start about what to do with
the infrastructure, whether to remove every-
thing or leave some of it in place for an arti-
ficial reef.”
A “rigs to reefs” approach—turning
decommissioned structures into habitats for
marine creatures—has been applied exten-
sively in the Gulf of Mexico. Such artificial
reefs have been shown to be extremely pro-
ductive fish habitats.
The scientists calculated
that removing the
platforms in their entirety
would result in 83%–99%
losses in fish biomass.
Three Scenarios
Dozens of drilling platforms (like Ellen and Elly, off the coast of Long Beach) are being decommissioned in For 24 of California’s oil- and g as-drilling
California. Credit: Bureau of Safety and Environmental Enforcement platforms, M eyer-Gutbrod and her col-
leagues analyzed the ecological impacts of
three decommissioning scenarios: leaving
the platform in place, removing the portion
L
ife finds a toehold just about anywhere, Times called one of those platforms, Holly, a of the platform in water shallower than
and the hulking edifices of offshore oil- “ghost ship.”) 26 meters, and removing the entire plat-
and gas-drilling platforms are no excep- There’s ongoing discussion about what to form. The team relied on observations col-
tion. But these structures, many of which are do with these structures as they’re decom- lected by divers, crewed submersibles, and
decades old, are starting to be decommis- missioned, said Erin M eyer-Gutbrod, a bottom trawl surveys between 1995 and
sioned. marine ecologist at the University of Califor- 2013.
Researchers have now calculated the eco- nia, Santa Barbara. “That’s going to mean Donna Schroeder, a marine ecologist at the
logical impact of losing these human-made Bureau of Ocean Energy Management in
habitats. Over 95% of fish biomass around a Camarillo, Calif., was instrumental in collect-
platform would be lost if it were removed ing some of those data. She rode to the sea-
completely, the team found. Another floor aboard the Delta, a petite submersible
option—severing platforms at a water depth painted bright yellow. “You had to [lie] down
of 26 meters and removing only the upper- horizontally in the front of the submersible
most part of the structure—would deplete and look out the portholes,” said Schroeder.
only about 10% of fish biomass, they con- Dives could last for several hours, so drinking
cluded. a lot of liquids beforehand was i ll-advised,
she said. “There’s not much privacy and not
Ghost Ships off California many options.”
Twenty-seven oil- and gas-drilling platforms Schroeder and other researchers manually
dot the coastline of California, most of them counted fish around the platforms. They used
in the Santa Barbara Channel. They were built estimates of the animals’ sizes and spatial
from the 1960s through 1980s, and they’re Donna Schroeder used this small submersible to col- density to calculate the amount of fish bio-
showing their age—several are in the early lect data for the study. Credit: Bureau of Ocean mass present near different parts of each
stages of decommissioning. (The Los Angeles Energy Management platform.
10 Eos // May 2020NEWS
to oil- and g as- cant difference makes sense, said Meyer-
drilling platforms Gutbrod, because there’s “all of this added
but can be dis- habitat” from a platform’s A-frame-shaped
lodged by waves or underwater structure.
intentional clean- “This work is on point,” said Claire Paris-
ing efforts, said Limouzy, a biological oceanographer at the
Meyer-G utbrod. University of Miami’s Rosenstiel School of
“They rain down Marine and Atmospheric Science in Virginia
and pile up into a Key, Fla., not involved in the research. The
big mound of shells findings make sense, she said, because the
beneath the plat- submerged portion of a platform attracts new
form.” That creates fish. “It’s a completely different commu-
new habit at, she nity,” said Paris-Limouzy, so removing that
said. “The spaces habitat is bound to decimate fish popula-
amongst the mus- tions.
sels make good These results were presented in February
hidey holes for the at Ocean Sciences Meeting 2020 (bit.ly/oil
An oil platform close to Catalina Island, California, supports a healthy reef habitat. smallest fish.” -r igs). They were also shared at a public
Credit: Adam Obaza, NOAA Fisheries West Coast, CC BY-NC-ND 2.0 (bit.ly/ forum in Long Beach, Calif., in January. It’s
ccbyncnd2-0) Biomass Losses important to disseminate these findings to
The scientists cal- the public, said M eyer-Gutbrod, because
culated that re- many of the platforms—and the marine hab-
moving the plat- itats they sustain—lie very close to the shore.
Meyer-Gutbrod and her collaborators found forms in their entirety would result in “We can see Holly right from the beach that
that blacksmith were common in the upper 83%–99% losses in fish biomass. But cutting we walk to from our house.”
water column. Rockfish inhabited the lower off just the top portion of the platforms—
reaches of most platforms, and assorted small leaving structures below a water depth of
fish darted among piles of mussel shells that 26 meters intact—would deplete, on aver- By Katherine Kornei (@KatherineKornei),
littered the platforms’ bases. Mussels cling age, just 10% of fish biomass. That signifi- Science Writer
Read it first on
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High Water: Prolonged Flooding on the Deltaic
Visit Eos.org daily for the latest Mississippi River
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New Models Give Global Picture of Mercury Content
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Lost in the Everglades
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Climate Change Will Reduce Spanish Olive Oil
Production
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SCIENCE NEWS BY AGU // Eos.org 11NEWS
Could Wildfire Ash Feed the Ocean’s Tiniest Life-Forms?
affected marine life. And as wildfires in some
places accelerate from drought, climate
change, and forest management practices, this
question may become more pressing.
Charred Fertilizer
Ladd and her colleagues devised an experi-
ment to test how plankton communities bob-
bing in the Santa Barbara channel’s coastal
waters would respond to an influx of ash-
leeched chemicals. They mixed the ash with
seawater, collected offshore in the channel
(where ash clouds blew during the Thomas
Fire), to create a yellowish mixture in the lab.
After straining out the floating bits, research-
ers enriched tanks full of naturally occurring
marine phytoplankton communities and let
them grow outside in natural light conditions.
At four different times over a week, they mea-
sured biomass and nutrients in the water. They
repeated the experiment during each season.
In the experiments, the phytoplankton
NASA’s Terra satellite caught images of smoke clouds from the Thomas Fire on 16 December 2017. Credit: NASA/ greedily sucked up the available organic and
Goddard Space Flight Center Earth Science Data and Information System (ESDIS) project inorganic nitrogen coming off the ash in the
form of nitrite, nitrate, and ammonium.
Nitrogen is a major component needed for
cells, but as Ladd explained, fire season, at
T
he Thomas Fire was the biggest wildfire Tiny floating organisms, called phytoplank- least in the Santa Barbara Channel where she
California had ever experienced at the ton, rarely have the nutrients they need to did the study, is a time when there are gen-
time. It burned over 280,000 acres and grow in much of the ocean, and they take erally fewer nutrients in the system.
destroyed more than a thousand structures in nutrients from wherever they can find them, The additional nitrogen helped phytoplank-
the final month of 2017. It painted the sky even from atmospheric sources. Past studies ton communities grow more than the controls
orange and brown, streaking across NASA’s on volcanoes have revealed how eruptions during summer, fall, and winter, a trend Ladd
satellite images of the state’s central and pumping iron-rich ash into the atmosphere could see by measuring the total biomass in
southern coast. could feed phytoplankton downwind, and dust the samples over time. During summer, fall,
Tanika Ladd, a graduate student at the Uni- drifting off the Sahara has long been recog- and winter, the a sh-fueled phytoplankton had
versity of California, Santa Barbara, was on nized as a “sandy fertilizer” for ocean plants. more than double the biomass than the con-
campus as the fires raged. “We were walking Much less attention has been paid to the trols. Plankton in the spring, on the other
around town, and everyone was wearing masks impact of wildfire ash. In the case of Austra- hand, showed less of an effect. The ocean has
because all this ash was falling,” she said. lia’s recent bushfires, which burned an area a huge influx of nutrients in the spring from
Ladd wondered how the ash might mingle roughly the size of the state of South Carolina ocean upwelling, so any seeding from the ash
with marine life offshore. So after a colleague and killed at least 34 people, experts didn’t didn’t have as great an impact.
collected fallen ash from the fire off car win- know how the ash accumulating along beaches The ash didn’t leech phosphorus, which
dows, she took the samples to the lab to find the ocean is often depleted of, but Ladd said
out. The tests suggest that nutrients leeched the exact chemicals leeched from the ash will
from the ash could spur phytoplankton change by location. “My findings might be
growth, particularly during times of the year slightly different than [those of] someone
when the ocean is short on nutrients. The The tests suggest that else who does something with the Australian
preliminary research is another step in
uncovering wildfire’s evolving fingerprint on
nutrients leeched from wildfires,” she said.
Earth’s landscape. the ash could spur Questions Adrift
An Inhospitable Ocean
phytoplankton growth, Ladd noted that the study is one of the first to
link wildfire ash and marine systems, but
Despite how Planet Earth, The Blue Planet, particularly during times many unknowns remain, such as the amount
and other documentaries depict the ocean, of ash deposited and what happens to it when
most of its surface is a barren, n
utrient-poor
of the year when the ocean it settles on the ocean. “If this is happening,
wasteland. is short on nutrients. then that atmospheric component of ash is
12 Eos // May 2020NEWS
Coastal Wetlands Save $1.8 Million
per Year for Each Square Kilometer
Researchers siphoned out the ash from the seawater
after letting it soak for 1 hour. Credit: Tanika Ladd
likely a more important nutrient source for
coastal systems,” she said.
Sasha Wagner, an assistant professor at
Rensselaer Polytechnic Institute in Troy, N.Y.,
who did not contribute to the work, said ash Mangroves in Florida’s Biscayne National Park near Miami. Credit: Yinan Che, Public Domain
deposition is an important source of nutrients
in surface water for freshwater streams and
lakes after a fire. “The fact that they were able
M
to capture these samples and start asking angrove forests, marshes, and sea- A Protective and Economic Boon
these questions, I think, is really important to grass beds protect inland areas from In addition to property damage data for trop-
kind of push this kind of research forward.” storm surges and strong winds. Over ical cyclones of all strengths, “our data set
Nick Ward, a research scientist at Pacific long periods, coastal wetlands like these build has considerably more spatial resolution,”
Northwest National Laboratory in Sequim, up sediment that mitigates sea level rise and Carson said, “which is a result of large
Wash., who was not involved with the local land subsidence. amounts of information on storm tracks,
research, said he’s curious to know how wild- A new analysis of property damage from property location, and wetland location all
fires might contribute to excess nutrients in Atlantic and Gulf of Mexico coastal storms has being digitized for use in a geographical
the marine environment. With large fires in shown that counties with larger wetlands information system basis.”
places like the Amazon, ash deposition “could suffered lower property damage costs than First author Fanglin Sun, formerly at UCSD
have a global impact if it’s changing produc- did counties with smaller wetlands. and now an economist at Amazon, added that
tivity or shifting communities,” he said. “Starting in 1996, the U.S. government “areas subject to flood risk in a county are
Ladd plans to analyze the DNA of plankton started to produce damage estimates for each more accurately estimated, based on local
from the experiment to see whether the ash tropical cyclone in a consistent manner,” elevation data and detailed information on
gave certain species an advantage over oth- explained coauthor Richard Carson, an econ- individual storm trajectories” and wind
ers. In a preliminary analysis using micro- omist at the University of California, San speeds throughout affected areas.
scopes, Ladd found that the ash did not seem Diego (UCSD) in La Jolla. Before that, the data The finer level of detail for the storm data
to change the abundance of one particular were collected only for hurricanes, which let the researchers finally begin connecting
type of phytoplankton, but further analysis is hindered past attempts to put a price on the wetland coverage and storm damage on a
needed. Ladd presented the work in February marginal value, or price per unit, of wetlands, county-by-county basis, Carson said. “A
at Ocean Sciences Meeting 2020 (bit.ly/ash he said. storm track moving a couple of kilometers
-phytoplankton). With the complete data set, the researchers one direction or the other allows the amount
examined all 88 tropical cyclones and hurri- of wetland protection to vary within the same
canes that affected the United States starting county.”
By Jenessa Duncombe (@jrdscience), Staff in 1996. That time period includes Hurricanes In terms of property damage, Sun and Car-
Writer Katrina and Sandy. son found that a square kilometer of wetlands
SCIENCE NEWS BY AGU // Eos.org 13NEWS
“The value coastal
wetlands provide for
storm protection is
substantial and should
be taken into account as
policy makers debate
the Clean Water Act.”
“so the specific nature of the storm when it
hits an area is likely to matter. [But] our
results suggest that, on average, there is no
difference.”
The team published these results in Pro-
ceedings of the National Academy of Sciences of
the United States of America (bit.ly/wetlands
-damage).
Wetlands at Risk
Most areas that have experienced storm-
related property damage in the past 20 years
have also lost wetland coverage, the research-
ers found. They calculated that Floridians
would have been spared $480 million in prop-
erty damage from Hurricane Irma alone had
the state’s wetland coverage not shrunk by
2.8% in the decade prior.
Moreover, recent changes to the Clean
Water Act have made the remaining coastal
wetlands more vulnerable (see b it.ly/Eos
Wetlands along the Atlantic and Gulf of Mexico coasts of the United States have a higher marginal value (dark -Clean-Water-Act).
colors) in densely populated urban counties but are worth relatively more in counties with weaker building “The federal government, with respect to
codes. Credit: Sun, F., and R. T. Carson (2020), Coastal wetlands reduce property damage during tropical the U.S. Clean Water Act, took the position
cyclones, Proc. Natl. Acad. Sci., 201915169, https://doi.org/10.1073/pnas.1915169117. that the previous wetland studies were not
reliable enough for use in assessing the ben-
efits and cost of protecting wetlands,” Carson
said.
saved an average of $1.8 million per year. Over age, coastline shape, elevation, building “The value coastal wetlands provide for
the next 30 years, an average unit of wetlands codes, and chance of actually experiencing storm protection is substantial and should be
could save $36 million in storm damage. damaging winds. And each of those variables taken into account as policy makers debate
Some wetlands were valued at less than fluctuated over the 20 years the team studied. the Clean Water Act,” Sun said. “It’s also
$800 per year per square kilometer and some Overall, the h
ighest-valued wetlands were worth noting,” she added, “that storm pro-
at nearly $100 million. That marginal value in urban counties with large populations and tection for property is just one of many eco-
depended on many factors, including a coun- the lowest-valued were in rural areas with logical services that wetlands provide. We
ty’s property values, existing wetland cover- small populations. However, wetlands pro- hope our study will spur future research
vided a greater relative savings against quantifying these other services as well.”
weaker cyclones and in counties with less With tropical storms and hurricanes
stringent building codes—areas that might expected to happen more often because of
not expect or plan for a tropical storm. climate change, the team wrote, wetlands
Over the next 30 years, an The team found no significant difference
in the marginal value of saltwater versus
will be more economically valuable than
ever.
average unit of wetlands freshwater wetlands or mangroves versus
marshes. “Forested wetlands tend to be bet-
could save $36 million in ter at reducing wind speed and marshes tend By Kimberly M. S. Cartier (@AstroKimCartier),
storm damage. to be better at absorbing water,” Carson said, Staff Writer
14 Eos // May 2020NEWS
Sustainable Agriculture Reflected in Cuba’s Water Quality
oxygen, tempera- Mind the Blooms
ture, pH, and con- The researchers also showed that Cuban
ductivity. They also waters tended to contain relatively low levels
took water and sed- of fertilizer-associated nutrients such as
iment samples, nitrates and phosphates. “The nitrate and
photographed the phosphate loads coming off of Cuba are a lot
area, and recorded lower than what’s draining down the Missis-
the region’s geo sippi River,” said Bierman. That makes sense,
graphical coordi- he said, because a rea-normalized fertilizer
nates using GPS. usage in Cuba is roughly half that of the
Bierman and his United States. “We put on a lot more fertilizer
colleagues shipped than the Cubans.”
coolers containing These results were published in GSA Today
the water and sedi- (bit.ly/Cuban-agriculture).
ment samples to Cuba is far from a self-sustaining nation—
several laborato- it still imports roughly 70% of the food its cit-
Scientists gather water quality measurements in central Cuba. Credit: Joshua Brown ries in the United izens need—but its agricultural practices are
States. There were a step in the right direction ecologically, said
plenty of logistics Bierman. They’re helping to stave off the
involved, he said. adverse effects of fertilizer runoff, for start-
B
eginning in 1990, Cuban agricultural “You can’t export material from Cuba without ers. When nutrients like nitrogen accumulate
technology did an a bout-face as a very thick stack of paperwork that’s been in the water, they can trigger harmful algal
small-scale, organic practices prolif- signed, stamped, and approved.” But the pro- blooms, which can produce toxins and liter-
erated after the fall of the Soviet Union. And cess is worth it, said Bierman, because sci ally choke out other forms of life. In the Gulf
now, just 3 decades later, the country’s river entists based in the United States are eager of Mexico, for example, there’s a large low-
chemistry reflects these sustainable prac- to work with Cuban samples. “We’ve gotten oxygen dead zone caused by such eutrophica-
tices, an international team of researchers an awful lot of science done.” tion.
showed. Nitrogen runoff is a big problem for many
Cuban river water has very high levels of Weathering at the Surface coral reefs worldwide, but Cuba’s ecosystem
cations and anions released by rock weather- The researchers found that rivers in central seems to have avoided a similar fate, said
ing, a natural process, and relatively low lev- Cuba contained high loads of dissolved solids Daria Siciliano, a marine ecologist at the Uni-
els of nutrients linked to fertilizer runoff. produced by chemical weathering of rocks. versity of San Francisco not involved in the
That’s good news for preventing harmful Using precipitation and runoff estimates, research. These results are “very valuable”
algal blooms in Cuba’s coral reefs, which rep- Bierman and his colleagues calculated that on because they provide an upstream explana-
resent a significant source of t ourist-driven average, roughly 160 tons of rock per square tion for the health of Cuba’s coral reefs, she
income for the Caribbean’s largest and most kilometer of land were being transported said.
populous nation, the researchers suggest. downriver each year because of chemical Bierman and his U.S.-based colleagues plan
weathering. “That’s how much mass is being to return to Cuba in August to sample rivers
Have Minivan, Will Travel removed,” said Bierman. That rate is compa- in other parts of the country. It’s a “challenge
In August 2018, Paul Bierman, a geologist at rable to the rates of other tropical environ- and a huge opportunity” to work in a place
the University of Vermont in Burlington, and ments and is in the top 25% of rates globally, so understudied by American researchers,
his colleagues convened in central Cuba. The the team concluded. said Bierman. He’s looking forward to con-
group included scientists and technicians Furthermore, the dissolved solids tended tinuing to strengthen collaborations with
from American and Cuban institutions. to be correlated with the surrounding rock Cuba-based scientists. “The bridges we’ve
Biologists, geologists, and physicists type, the scientists showed. That relationship built for science have gone far ahead of what’s
rubbed shoulders during the fieldwork, said is somewhat surprising, the team suggests, going on politically between our two govern-
team member Alejandro García Moya, an because it implies that river water is in direct ments.”
Earth scientist at the Centro de Estudios contact with weatherable rock. (In tropical
Ambientales de Cienfuegos in Cuba. “We had climates like Cuba’s, chemical weathering
the opportunity as scientists to share our should occur far below the surface.) One By Katherine Kornei (@KatherineKornei),
experience and knowledge with people from explanation, Bierman and his colleagues pro- Science Writer
different research and science perspectives.” pose, is that tectonic uplift in Cuba—the
The team traveled in two yellow minivans island is located at the boundary of the North
and visited 25 rivers across central Cuba. American and Caribbean plates—provides
They typically went to two or three field sites a constant supply of fresh rock that is con u Read the latest news
per day. At each site, the scientists made tinually incised by rivers and dissolved by at Eos.org
measurements of the river water’s dissolved groundwater.
SCIENCE NEWS BY AGU // Eos.org 15You can also read
