Fiber-optic sensors reveal how farming destroys soil's natural structure

Chinese Academy of Sciences Headquarters

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Soil is often perceived simply as "dirt," but in reality, it is a dynamic, living system that acts as the Earth's natural sponge. Unfortunately, common agricultural practices—including deep plowing and the use of heavy machinery—can severely disrupt this natural system, according to a new study led by Dr. SHI Qibin from the Institute of Geology and Geophysics of the Chinese Academy of Sciences, in collaboration with international partners.

The study, published in Science on March 19, shows that healthy soil contains a natural internal "plumbing" network of microscopic pores and channels that allow water to infiltrate deeply into the ground, where it becomes available to plant roots. Frequent plowing or heavy tractor traffic not only disrupts soil structure but also reduces its ability to help crops withstand both flooding and drought.

The team used a novel technique to observe subsurface soil processes without excavation. The researchers converted standard fiber-optic cables—similar to those used in high-speed internet networks—into a large-scale sensor array installed across an experimental farm at Harper Adams University in the United Kingdom. By using the array to detect tiny ground vibrations generated by water flow, the researchers were able to monitor water movement through the soil minute by minute.

Using high-resolution fiber-optic data, they observed that rainfall tends to pool near the surface in heavily cultivated soil. Because water remains shallow, it evaporates rapidly in sunlight, leaving deeper soil layers dry. By contrast, undisturbed soils act as efficient natural filters, quickly absorbing water and storing it in deeper layers where plants can access it during dry periods.

To explain these observations, the research team developed a dynamic capillary stress model that assumes an "ink-bottle effect" within soil pore structures. In other words, water flows into a pore (bottle) with ease, but flows out with more difficulty. These differences are attributable to capillary forces that hold soil together more or less strongly, depending on whether the soil is drying or wetting—even when overall moisture content remains the same.

This model is much more complex than traditional soil mechanics, which generally assumes that soil strength depends primarily on total water content.

"Rather than a simple collection of particles, soil is a porous medium in which the structure functions like capillary vessels within the water cycle," Dr. SHI explained.

The findings underscore the need to rethink agricultural land management. Excessive tillage and soil compaction caused by heavy machinery do not merely rearrange soil particles; they break the invisible mechanical bonds that allow soil to breathe, circulate water, and maintain ecological stability.

Preserving these natural structures will be critical to helping crops adapt to increasingly extreme weather conditions driven by climate change, the researchers explained.

The study is noteworthy for introducing distributed fiber-optic sensing—and the larger field of agroseismology—to assess the health of soil water systems without physically disturbing the land. By "listening" to the Earth in this way, scientists and farmers will be able to "diagnose" agricultural soil conditions in real time and develop more resilient strategies for sustainable food production.

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Journal

Science

DOI

10.1126/science.aec0970 

Article Title

Agroseismology and the impact of farming practices on soil hydrodynamics

Article Publication Date

19-Mar-2026

 

When the Earth moved

Study shows movement of tectonic plates 3.5 billion years ago

Harvard University

By Kermit Pattison / Harvard Staff Writer 

The history of the Earth is written on the great tablets of tectonic plates.

The motions of plates shaped land masses, formed oceans, and created the varied climates and habitats that set the stage for evolution and the diversity of life.

But this grand drama begins with a deep mystery: just when did the continental and oceanic plates begin to drift? Did the lithosphere begin to move soon after the formation of the Earth 4.5 billion years ago or only in the last billion years?

A new study by Harvard geoscientists shows the oldest-yet direct evidence of plate movement by 3.5 billion years ago. In a study published March 19 in Science, the team found that plate movements—though not necessarily the modern type—shaped the early history of our planet.

“There has been a huge range of ages suggested for timing,” said lead author Alec Brenner, PhD ’24, who conducted the research in the Department of Earth and Planetary Sciences (EPS) in the Harvard University Kenneth C. Griffin Graduate School of Arts and Sciences. “With this study, we're able to say three and a half billion years ago, we can see plates moving around on the Earth surface.”

The new revelations came from some of the oldest well-preserved rocks in the world, the Pilbara Craton in western Australia, which contains formations from the Archean Eon when the Earth was hosting early microbial life and under heavy bombardment by astronomical objects. The Pilbara area contains evidence of some of the earliest known life, stromatolites and microbialite rocks deposited by single-celled organisms such as cyanobacteria.

A team led by Roger Fu, Professor of Earth and Planetary Sciences at Harvard University, has been conducting research in East Pilbara since 2017. Fu specializes in paleomagnetism, a branch of geophysics that examines changes in the Earth’s magnetic fields to reconstruct the early history of the planet. Last year, they published a paper about an ancient meteor impact at the same site.

In addition to revealing the properties of the Earth’s magnetic field, paleomagnetism can also be used to track the motions of plates. By analyzing the magnetic signals of ancient mineral grains, the researchers can infer the orientation and latitude of the rocks at the time of formation—thus using the ancient samples like paleo GPS units.

“Almost everything unique about the Earth has something to do with plate tectonics at some level,” said Fu. “At some point, the Earth went from something not that special, just another planet in the solar system with similar materials, to something very special. A very strong suspicion is that plate tectonics started Earth down this divergent track.”

In the new study, the researchers analyzed more than 900 rock samples collected from more than 100 sites scattered across an area called the North Pole Dome.

They extracted cylindrical samples or “cores” using an electric drill with a hollow bit and diamond teeth, kept cool by a hand-pump garden sprayer. Afterwards the position of the sample was precisely recorded with an instrument inserted into the hole containing a compass and goniometer (a device for measuring angles).

Back at Harvard, the cores were sliced into sections like cookies, lined up on trays, and placed in a magnetometer, a machine that can measure magnetic signals 100,000 times more faint than a compass needle. The samples were repeatedly measured while being heated to progressively hotter temperatures up to 590 degrees Celsius until the magnetite minerals lost their magnetization. The step-by-step heating allows researchers to isolate magnetic signals from different periods in the rock’s history. All told, the analysis took about two years.

“We took a really big gamble,” said Brenner, now a postdoc at Yale. “Demagnetizing thousands of cores takes years. And boy, did it pay off! These results were beyond our beyond our wildest dreams."

In ferromagnetic minerals, the orientation of the electrons serves like a compass needle pointing towards the magnetic pole. The electron orientation also provides hints about the position on the three-dimensional globe relative to the magnetic pole when the rock formed—thus providing an indication of latitude.

By analyzing a series of rocks spanning 30 million years just after 3.5 billion years ago, they found that part of the East Pilbara formation shifted in latitude from 53 degrees to 77 degrees—a drift of tens of centimeters annually over several million years—and rotated clockwise by more than 90 degrees. (Because the magnetic pole occasional reverses, it remains uncertain whether this motion occurred in the northern or southern hemisphere.) Within about 10 million years, the motion slowed and followed by a period of little motion.

To compare this motion with Archaean sites elsewhere, the researchers examined a contemporary site in South Africa, the Barberton Greenstone Belt. Previous paleomagnetic studies showed that the latter was located near the equator and nearly stationary during the same time interval. Apparently the two distant regions had different patterns of drift.

In the modern world, the North American and Eurasian plates now are moving away from each other by about 2.5 centimeters, or 1 inch, per year.

It remains an open question about when and how the Earth took on its current form of plate tectonics, which geophysicists call an “active lid.” Various theories posit that the early Earth had a “stagnant lid” (a single unbroken global plate), a “sluggish lid” (slowly moving plates), or “episodic lid” (plates moving sporadically). The new study rules out a stagnant lid but cannot distinguish which model of plate movement was most likely; the Fu team is pursuing additional studies to answer this question.

“We're seeing motion of tectonic plates, which requires that there were boundaries between those plates and that the lithosphere wasn't some big, unbroken shell across the globe, as a lot of people have argued before,” said Brenner. “Instead, it was segmented into different pieces that could move with respect to each other.”

The team also discovered the oldest-known case of a geomagnetic reversal—a phenomenon in which the magnetic field of the planet occasionally flipped. After a reversal, a compass needle would point south instead of north.

This phenomenon is believed to be governed by the “dynamo action” involving the convection of molten iron in the Earth core that produces electrical currents and magnetic fields. The last reversal occurred about 780,000 years ago.

Fu said the new evidence suggests that 3.5 billion years ago, reversals occurred less frequently than in more recent history. “It's not by itself conclusive, but it suggests that maybe the dynamo was in a slightly different regime than today,” he said.

 

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Journal

Science

DOI

10.1126/science.adw9250 

Article Title

Paleomagnetic detection of relative plate motions and an infrequently reversing core dynamo at 3.5 Ga

Article Publication Date

19-Mar-2026

 

Mayo Clinic study demonstrates safety, feasibility of delivering chemotherapy at home

Mayo Clinic

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JACKSONVILLE, Fla. — In a study published in NEJM Catalyst, Mayo Clinic researchers have demonstrated that chemotherapy can be safely delivered in patients' homes.

The study evaluated Mayo Clinic's Cancer CARE Beyond Walls (Connected Access and Remote Expertise), a model that combines virtual care, remote patient monitoring and in-home clinical services to deliver cancer treatment outside traditional infusion centers.

In the pilot study, a multidisciplinary team delivered 93 IV chemotherapy infusions to 10 patients in their homes. Researchers reported no treatment-related infusion reactions or catheter-related infections, supporting the safety and feasibility of this approach.

"Cancer care has traditionally required patients to spend long hours in infusion centers, often far from home," says Roxana Dronca, M.D., site director of the Mayo Clinic Comprehensive Cancer Center in Florida and director of Mayo Clinic Cancer CARE Beyond Walls. "This model allows us to safely bring high-quality care directly to patients, reducing burden while maintaining the standards patients expect from Mayo Clinic."

The study highlights the potential of home-based chemotherapy to reduce the physical, emotional and financial burdens associated with cancer treatment. Patients avoided travel time and experienced fewer disruptions to daily life while maintaining a continuous connection with their care team through virtual visits and remote monitoring.

Most participants surveyed reported high satisfaction with at-home care and said they would recommend the model to others.

"This approach is about more than convenience," Dr. Dronca says. "It's about improving quality of life during treatment and expanding access to care for patients who may face barriers to reaching traditional cancer centers."

To build on these findings, Mayo Clinic is still enrolling patients in a randomized clinical trial that launched in August 2023 to evaluate home-based chemotherapy compared with standard infusion care. This study will examine safety, patient experience, outcomes and costs, with the goal of expanding access to high-quality cancer care and reducing barriers to clinical trial participation.

Dr. Dronca is the first author of the pilot study, and Cheryl Willman, M.D., the Stephen and Barbara Slaggie Executive Director, Mayo Clinic Cancer Programs, is the senior author. For a complete list of authors, disclosures and funding, review the study.

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About Mayo Clinic
Mayo Clinic is a nonprofit organization committed to innovation in clinical practice, education and research, and providing compassion, expertise and answers to everyone who needs healing. Visit the Mayo Clinic News Network for additional Mayo Clinic news.

About Mayo Clinic Comprehensive Cancer Center
Designated as a comprehensive cancer center by the National Cancer Institute, Mayo Clinic Comprehensive Cancer Center is defining the cancer center of the future, focused on delivering the world's most exceptional patient-centered cancer care for everyone. At Mayo Clinic Comprehensive Cancer Center, a culture of innovation and collaboration is driving research breakthroughs in cancer detection, prevention and treatment to change lives.

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Journal

NEJM Catalyst

Article Title

Cancer CARE (Connected Access and Remote Expertise) Beyond Walls — Safety, Feasibility, and Patient Experience of Home-Based Chemotherapy

Article Publication Date

18-Mar-2026

 

The freshwater hidden beneath the Great Salt Lake

In a first of its kind breakthrough, Utah geophysicists used electromagnetic data from airborne surveys to characterize a deep freshwater reservoir under Utah shrinking saline lake

University of Utah

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image: 

A helicopter crew prepares to fly airborne electromagnetic survey equipment from a staging area on Antelope Island on Feb. 28, 2025.

view more 

Credit: Brian Maffly, University of Utah

A potentially huge underground reservoir of freshwater beneath the Great Salt Lake is coming into sharper focus with a new study that used airborne electromagnetic (AEM) surveys to X-ray geologic structures under Farmington Bay and Antelope Island off the lake’s southeastern shore.

An analysis of this data by University of Utah geophysicists shows that freshwater saturates the sediments beneath the lake’s hypersaline surface to depths of 3 to 4 kilometers, or about 10,000 to 13,000 feet. The  helicopter-borne geophysical survey was conducted last year after Utah scientists documented freshwater welling up under pressure at several spots on the lake’s exposed playa in Farmington Bay, manifesting as strange phragmites-choked mounds.

The study demonstrated for the first time the ability of AEM methods to detect freshwater underneath thethin layer of conductive salt water at the surface of the Great Salt Lake, according to lead author Michael Zhdanov.  His team also characterized the spatial extent of the freshwater reservoir beneath Farmington Bay and studied the potential depth of freshwater-saturated sediments by delineating the basement structure.

“We were able to answer the question of how deep is this potential reservoir, and what is its spatial extent beneath the eastern lake margin.  If you know how deep, you know how wide, you know the porous space, you can calculate the potential freshwater volume,” said Zhdanov, a distinguished professor of geology & geophysics and director of the Consortium for Electromagnetic Modeling and Inversion, or CEMI.

A larger state-funded research effort focused on a newly discovered aquifer

The results appear in the Nature-affiliated journal Scientific Reports. This study is part of a larger research project led by the U’s Department of Geology & Geophysics and funded by the Utah Department of Natural Resources to understand the groundwater beneath Great Salt Lake, the largest terminal lake in the Western Hemisphere.

Overseen by some of the geology department’s most senior faculty and their graduate students, this effort has already resulted in two other important papers, with more to follow.

The evidence produced in this new study suggests that freshwater is entering the subsurface toward the lake’s interior, not its periphery as would be expected, according to hydrologist Bill Johnson, a co-author on all the Great Salt Lake groundwater papers.

“The unexpected part of this wasn't the salt lens that we see near the surface across the playa. It's that the freshwater underneath it extends so far in towards the interior of the lake and possibly under the entire lake. We don't know,” Johnson said on a recent appearance on KPCW’s Cool Science Radio show. “What we would normally expect as  hydrologists is that that brine would occupy the entire volume underneath that lake. It's denser than the freshwater. You'd expect the freshwater from the mountains to come in somewhere at the periphery. But we find it's coming in towards the interior. And there's what appears to be deep volume of this freshwater coming in underneath that saline lens.”

A potential water source to mitigate dust pollution

These studies were triggered by the appearance in recent years of circular mounds, each 50 to 100 meters in diameter and covered with 15-foot-tall thickets of reeds, on the dried-out bed of Farmington Bay. The lake’s declining water levels have exposed 800 square miles of lake playa which is now becoming a major source of dust pollution blowing into Utah’s population centers.

Johnson, a professor of geology and geophysics, wants to explore whether the artesian groundwater could be safely tapped to mitigate the dust which contains toxic metals.

“There are beneficial effects of this groundwater that we need to understand before we go extracting more of it. A first-order objective is to understand whether we could use this freshwater to wet dust hotspots and douse them in a meaningful way without perturbing the freshwater system too much,” Johnson said. “To me, that's a primary objective because it's very practical and it's unlikely we'll be able to fill Farmington Bay and other parts of the playa enough to avoid some dust spots appearing at the higher elevations. This would be a great way to get at that.”

Johnson and his Utah colleagues, including Mike Thorne and Kip Solomon, are seeking funding to expand the groundwater studies to cover a much larger portion of the lake.

This latest paper measured electrical resistivity to a depth of about 100 meters via airborne electromagnetic surveys to discern freshwater from brine, which is far more electrically conductive. To see if this could be done, Johnson and Zhdanov hired a geophysical crew  from Canada to fly electromagnetic equipment dangled under a helicopter in February 2025. The helicopter flew 10 east-west survey lines spanning Farmington Bay and across the northern portion of Antelope Island, for a total of 154 miles.

Looking under the playa

Zhdanov’s team analyzed the resulting data to create a map of the saline-freshwater interface. It showed how one phragmites mound sat above a spot where freshwater pushed through a gap in the impervious layer underlying the lake.

“Red means very conductive, blue is resistive,” Zhdanov said while explaining the map. “You clearly see near surface is saline water, 10 meters underneath is resistive freshwater. You see clearly it’s everywhere.”

Zhdanov’s research group CEMI has developed a technique to build 3D images of Earth’s subsurface by integrating electromagnetic data gathered aerially with magnetic measurements. Applied in this study, the researchers were able to create a tomographic image extending deep beneath Farmington Bay, providing critical insights into its geological and hydrological structure.

The results of the magnetic data inversion show that the basement under the Farmington Bay playa, is relatively shallow, less than 200 meters down, but then abruptly plunges to 3 to 4 kilometers. The drop-off, which occurs under the phragmites mound, represents a significant structural boundary that should be more fully explored.

“This is why we need to survey the entire Great Salt Lake. Then we’ll know the top and the bottom,” Zhdanov said. “To study the top we use airborne electromagnetic methods, which gives us the thickness of the saline layer and where the freshwater starts under the saline layer. To study the bottom, we use magnetic data. We use different techniques to study the vertical extent of this freshwater-saturated sediments, to find the  depth to the basement.”

This pilot study covered just a sliver of the lake, but Zhdanov believes his team can fly airborne electromagnetic survey lines spanning the lake’s entire 1,500-square-mile footprint.

A lake-wide airborne survey could help guide regional water-resource planning and inform similar searches for freshwater  under terminal lakes worldwide.

#####

The study was published in Scientific Reports under the title, “Airborne Geophysical Imaging of Freshwater Reservoir Beneath the Eastern Margin of Great Salt Lake.” Co-authors include Michael Jorgensen, Bill Johnson,  and Kip Solomon of the U Department of Geology & Geophysics, and Leif Cox of TechnoImaging, a university spinoff founded by Michael Zhdanov in 2005.  Funding came from Utah Department of Natural Resources, the Great Salt Lake Commissioners' Office, and the Consortium for Electromagnetic Modeling and Inversion (CEMI) at the University of Utah.

Map of the airborne electromagnetic survey area overlaid on the ESRI World Imagery basemap. Flight-

line locations are shown in red and cross Antelope Island and Farmington Bay. The circles indicate locations of phragmites mounds.

University of Utah

 

A helicopter lifts off from Antelope Island carrying electromagnetic survey equipment for a geophysical data-gathering mission over Farmington Bay in February 2025.

Credit

Brian Maffly, University of Utah

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JournaL

Scientific Reports

DOI

10.1038/s41598-026-40995-5 

Method of Research

Observational study

Subject of Research

Not applicable

Article Title

Airborne Geophysical Imaging of Freshwater Reservoir Beneath the Eastern Margin of Great Salt Lake