As you drive across the Wabash River on a bridge connecting Illinois and Indiana, you may catch glints on the water or see a bird soar toward the canopy of trees lining the riverbank. What you likely won’t see is something super that happens to be sitting directly beneath you.  

This superhero doesn’t wear a cape. Instead, it hides within a little brown house somewhat resembling an outhouse. It is, in fact, a super streamgage.  

Although USGS streamgages are nationally famous for taking accurate water level measurements, a select few have a superpower: the ability to help monitor water quality. USGS scientists use these gauges, among many tools, to monitor Earth phenomena. Researchers study environmental contaminants, investigate geothermal impacts on the landscape, decipher satellite images, study wildland fires, and map ungulate migrations across the Nation. 

To celebrate the 52nd Earth Day, we’ll highlight six ways that USGS provides science to help us better understand our home planet.  

1. Is it a giant birdhouse? A phone box? It’s a super gauge! 

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The Wabash River winds and bends for 500 miles across the state of Indiana. It’s a significant source of drinking water and home to over 100 sensitive plants and animals.  

The Wabash meets the Ohio River at the Indiana, Illinois, and Kentucky junction. The Ohio then flows southwest until it joins the Mississippi River, which ultimately flows into the Gulf of Mexico.  

So, what goes into the Wabash, like fertilizer runoff, doesn’t stay in the Wabash. Runoff and wastewater bring excess nutrients, specifically nitrogen and phosphorus, into the river, spurring algae growth, depleting oxygen, and creating a dead zone. Conditions in the Wabash eventually contribute to the Gulf of Mexico’s hypoxic, or low oxygen, zone. 

“We installed super gauges along the Wabash and Ohio Rivers so we can capture their major tributaries and get a snapshot of what’s entering and leaving each state,” Molly Lott, a hydrologic technician with the USGS Ohio-Kentucky-Indiana Water Science Center, said.  

Super streamgages’ frequent measurements reveal how nutrients move through the watershed. Scientists use that information to better understand how what we do on land affects the overall watershed’s health and help inform actions we can take to preserve our water resources for the future.   

The USGS super gauge on the Wabash near the town of New Harmony, Indiana is part of that network of super gauges, specifically aiming to understand what’s leaving Indiana and Illinois. In addition to its usual streamgage duties of continuously measuring water height, temperature, dissolved oxygen, pH, and turbidity (or how brown the water gets from suspended sediment), the super gauge also regularly measures the amount of nutrients in the water. 

Each super streamgage network across the country is operated by local USGS Water Science Centers with support from USGS, other federal agencies, state and local agencies, nonprofit organizations, and private entities.  

2. Smile! You’re on camera. 

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If Earth Day had one picture, what would it be? A regal tree, its branches stretching skyward for a sun hug? A glittering brook, its crystalline water sliding effortlessly over rounded river rocks? Or, most likely, a colorfully mottled sphere gleaming against the blankness of space. 

Blue Marble, NASA's infamous image of Earth from space, was captured by the Apollo 17 crew in 1972 and has inspired Earthlings ever since. Today, the USGS partners with NASA to gather images of Earth from above using state-of-the-art Landsat satellites. 

The latest Landsat mission, Landsat 9, launched in September 2021 and began providing Earth observation data to the public in February 2022. Each day, Landsat 9 collects approximately 750 images of Earth that are processed, archived, and distributed from the USGS Earth Resources Observation and Science Center. Working in tandem with Landsat 8, Landsat 9 will significantly improve the nation’s land imaging, sustainable resource management, and climate science capabilities. 

The Landsat Program has been providing global coverage of landscape change since 1972 – the same year Blue Marble became a star. Landsat’s long-term data record provides critical understanding of environmental and climate changes occurring nationally and globally. This data is used by people worldwide for scientific, agricultural, disaster management, software development, educational, resource management, and policy-making purposes. 

If Blue Marble makes you starry-eyed, Landsat’s artistic capabilities might also appeal to you. The USGS Earth as Art collections use satellite sensors and the interplay between visible and invisible light to capture some of the earth’s most glamorous portraits. 

Learn more about USGS Earth imaging science on the USGS National Land Imaging Program website. 

3. Studying the toxins around us.  

Picture it. May 2016. An extensive, thick algal bloom covers 33 square miles (85 kilometers) of Florida’s Lake Okeechobee. The bloom is so intense, it’s spotted in a Landsat 8 satellite image.   

The blue-green algae, also called cyanobacteria, are a regular phenomenon in the lake during summer, but excessive nutrients can spur their growth and help create harmful algal blooms (HABs), some of which are potentially toxic. Sometimes these CyanoHABs release toxins, called cyanotoxins, that can threaten human and aquatic ecosystem health and disrupt economies that depend on water bodies for income.  In the summer of 2014, the town of Toledo, Ohio shut down drinking water for the entire city after detecting algal toxins in Lake Erie.  

CyanoHABs and their toxins can harm people, animals, aquatic ecosystems, the economy, drinking water supplies, property values, and recreational activities, like swimming and fishing. USGS scientists are combining traditional and emerging technologies to study these algal blooms and better understand why some become toxic while others do not. Researchers are also developing new information on environmental exposures to the public and toxicity to wildlife.  

“Humans and the ecosystems where they coexist share health concerns from contaminant exposure,” Michael Focazio, the program coordinator for USGS environmental health programs, said.   

Researchers study a wide variety of contaminants, from those that are naturally occurring, like algal toxins, arsenic, lead, mercury, and uranium, and those that are manufactured, like fertilizer, pesticides, pharmaceuticals, and per-and polyfluoroalkyl substances, or PFAS – also known as “forever” chemicals.  “One thing is for sure,” Focazio, said. “We have repeatedly found that contaminants do not occur alone in our ecosystems and drinking water resources; rather, they occur as complex mixtures of contaminants.”  

USGS scientists look at how these contaminants enter and move through our environment to better understand how humans and wildlife are exposed and potentially sickened.  

PFAS, for instance, are seemingly everywhere, from nonstick cookware to waterproof clothing, and have been detected in our watersheds and aquifers. Although they are useful, they also pose potential health risks, including cancer and hormone disruption.   

The USGS recently released a strategy for addressing current gaps in our understanding of PFAS science. It pulls on USGS expertise in monitoring water, soils, and biota to analyze how PFAS move through the environment and impact tap water and wildlife.  

“We’re looking at fish, mussels, birds, and other wildlife that coexist in ecosystems with humans because they might act as canaries in the coal mine,” Focazio said. 

4. Where do the buffalo roam?  

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Scientists can find clues about the health of our planet by studying what Earth’s living things are up to. Take ungulates, for example. Ungulates are large mammals like bison, moose, elk, and deer that have hooves. In places like the Rocky Mountains, many ungulates migrate from place to place depending on the season. 

However, climate change is affecting these seasonal patterns and behaviors, and the cascading effects are not well understood. The USGS studies animal movement, behavior, and population dynamics to better understand how a changing world impacts the nation’s culturally, economically, and ecologically valuable ungulate populations.  

Tabitha Graves, a research ecologist with the USGS Northern Rocky Mountain Science Center, is researching how climate-related changes in the availability and quality of food in the West affect mule deer. Consider spring greening.

"The beginning of spring has already shifted dramatically in many areas of the western U.S.,” Graves said. “Earlier springs could have downstream effects on many plants and animals, including ungulates." 

True to our map-making legacy, USGS scientists recently worked with other federal and state wildlife biologists to map ungulate migrations across the western U.S. These cutting-edge maps can help land managers and conservationists pinpoint actions necessary to keep migration routes open and functional for ungulate populations. They can also help researchers monitor and limit the spread of contagious diseases, such as chronic wasting disease, which are becoming prevalent in wild populations of North American cervids, or animals in the deer family. 

The USGS released its second volume of ungulate migration maps earlier this month – just in time for Earth Day. So where do the buffalo and their hooved homies roam? Now there’s a map for that. 

5. Hot takes on the landscape. 

A town known for its fluffy white snow and appeal to skiers and snowboarders may not seem like a place to tap into heat generated by the center of Earth, but that’s exactly what happens at the Casa Diablo Hot Springs and Geothermal Facility near Mammoth Lakes in eastern California.  

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The power plant connects to the Long Valley Caldera’s plumbing system at a point where hot water rises to only a few hundred feet below ground. Production wells draw the 338-degree Fahrenheit water to generating units that convert the water’s thermal energy to isobutane, which vaporizes and powers turbine generators. Once the water cools, it’s injected back into the ground near the power plant.  

The overall process results in no net withdrawal of geothermal water, but the water’s movement affects the hydrologic system. USGS scientists take routine measurements in areas around the caldera to look for physical and chemical changes as part of longstanding efforts to monitor conditions and assess potential contamination. 

As part of a new effort to study the environment in less time and over wider areas than traditional on-the-ground methods, a team of USGS researchers is putting mapping and monitoring tools on unoccupied aerial systems.  

“We’re developing systems using drones to acquire critical baseline information that will allow us to map features and to monitor changes through time,” Jonathan Glen, a USGS research geophysicist with the Geology, Minerals, Energy, and Geophysics Science Center, said.  

The researchers are flying drones over Shady Rest Park in Mammoth Lakes to better understand why it’s experiencing tree kills, gas vents, and heated ground, among other features. 

The drones have equipment that take magnetic measurements to map the area’s underlying geology. They have instruments that sense heat with thermal infrared sensors. They also have sensors that collect gas emission measurements as well as cameras that take high-resolution images to help them create 3-D models of the landscape.  

“We hope our efforts in Mammoth Lakes inspire others to combine aerial and on-the-ground monitoring tools to study similar systems,” Glen said.

6. This science is on fire. 

California, Colorado, Oregon, and Arizona. Canada, Australia, Russia, and Bolivia. Wildlands across the nation and Earth have experienced catastrophic fires. Large, high-intensity wildfires can be devastating to life and property, and 2017, 2018, and 2020 were particularly damaging and deadly years in the U.S. 

Low-intensity fires are natural on our planet and are, in fact, essential to the health of fire-adapted forest ecosystems. It’s a different type of threat that has people fired up. 

Scientists warn that highly destructive, fast-moving blazes like those that are all-too familiar in the western U.S. are likely to increase in the future. That’s why the USGS employs more than 100 scientists whose research focuses on fire-related topics – they could be considered the firefighters of the science world. 

Last year, the USGS released its hot new Wildland Fire Science Strategy. This plan describes the critical needs for wildfire research over the next five years and can be used to better understand the balance between fire’s benefits and its detrimental impacts. The resulting USGS research will provide land managers with the information needed to tackle fire risks before they occur, during wildfire response, and after the smoke clears. 

"The USGS Wildland Fire Science Strategic Plan provides a roadmap to develop the best available science to support wildland fire management," said Paul Steblein, USGS Wildland Fire Science Program Coordinator.  

The plan identifies key research needs and outlines steps the USGS should take to ensure this plan is a success, including engaging wildland fire stakeholders in our research process, effective communication, and organizational support, according to Steblein. 

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Priorities of the new USGS wildfire science strategy include: 

• Understanding the relationship between destructive wildfires and climate change; 

• Supporting underserved rural communities and Tribes; 

• Assessing post-wildfire flooding and debris-flow hazards; 

• Using artificial intelligence with satellite imagery to detect fire boundaries and develop burn severity maps; and 

• Integrating different research branches to improve planning for and response to fire-related disasters. 

The full USGS Wildland Fire Science Strategic Plan is available online.