Category: US Geological Survey

Category Added in a WPeMatico Campaign

Posted on

Are those volcanoes…or a volcanic field?

Source: US Geological Survey

Yellowstone Caldera Chronicles is a weekly column written by scientists and collaborators of the Yellowstone Volcano Observatory. This week’s contribution is from Mark Stelten, research geologist with the U.S. Geological Survey and deputy Scientist-in-Charge of the Yellowstone Volcano Observatory.

What is the difference between a volcano and a volcanic field? This isn’t the start of a bad joke, but rather an important question geologists try to answer when they seek to characterize volcanic hazards in a particular region. First let’s consider what types of volcanoes are common in the world. 

Volcanoes come in all shapes and sizes. Typically, we think of volcanoes as steep, conical structures the size of a mountain, such as Mount St. Helens in Washington or Mount Shasta in northern California, that are built from successive lava flows and ash deposits. These are referred to as stratovolcanoes. Or perhaps we think of calderas like Yellowstone that are large, basin-shaped depressions formed when large volumes of magma are erupted from a shallow reservoir. Another common volcano type is a shield volcano, which is a broad, low relief volcano built up by successive lava flows, like Mauna Loa in Hawaiʻi. A more common type of volcanic feature is a cinder cone, or scoria cone, that consists of a conical hill formed by accumulation of solidified fragments of lava that fall around the vent of a single eruption (typically basalt to basaltic-andesite in composition). Cinder cones often have lava flows associated with them. Each one of these features is considered an individual volcano. However, it is often the case that multiple volcanoes in a similar geographic area are related to each other. This is where the concept of a volcanic field comes from. 

Volcanic fields, or volcanic centers, are places where there are many different volcanoes in a similar location, and generally the eruptions that formed these volcanoes are thought to be related to a common magma source or a magma generation process. For example, the Yellowstone Plateau Volcanic Field consists not only of the modern-day Yellowstone Caldera, but two older calderas that formed approximately 2.1 million years ago and 1.3 million years ago, as well as numerous rhyolite lava flows and lava domes that fill in these calderas and numerous basalt eruptions that occurred outside these calderas and formed small cinder cones and lava flows.

Google Earth image of the newly proposed Idaho Volcanic Field, with recent eruptions indicated, and Craters of the Moon lava field. Major city centers surrounding the volcanic field are included to provide spatial context.

Although it is sometimes clear when separate volcanoes are related, this is not always the case—it can be quite hard to tell if a volcano exists in isolation or is part of a volcanic field. A good example of this is young volcanism in the eastern Snake River Plain in Idaho. Over the last 15,000 years, eruptions in the Eastern Snake River plain include the Cerro Grande lava field, North Robbers lava field, South Robbers lava field, Hells Half Acre lava field, Wapi lava field, and the Black Butte Crater lava field. These eruptions occurred over an area that is approximately 100 miles east-west by 55 miles north-south. Each lava field is interpreted to have formed from a single eruption event (although the length of each event varied) and formed small shield volcanoes or long lava flows. In the past, these have been treated as individual volcanoes and not as part of a volcanic field. The similar timing, compositions, and overall locations, however, suggest that the eruptions are broadly related.

Fissure within the Wapi lava field, a volcanic feature in the eastern Snake River Plain of Idaho.  Photo by Michael Ort, October 14, 2022.

Based on this geologic evidence and a recent analysis of volcanic hazards that could impact the Idaho National Laboratory, USGS scientists are proposing to define a new volcanic field tentatively called the “Idaho volcanic field” that includes all these lava fields. Notably, Craters of the Moon, which is in the same area, is not included in the Idaho volcanic field. This is because Craters of the Moon is unique from the other volcanoes in that it has erupted numerous times from the same general location (although not from the same specific volcanoes), and recent eruptions have a unique composition compared to other young eruptions in the eastern Snake River Plain.

So, why does any of this matter in a practical sense when it comes to understanding volcanic hazards? The main benefit of defining a volcanic field that encompasses all of the abovementioned volcanoes is that it better reflects the geologic reality in that area. For example, if we treat each of those volcanoes as an individual feature, then the implication is that future eruptive activity would probably be in the same area as those volcanoes. Instead, a more realistic view may be that an eruption could occur within any part of the Idaho volcanic field, even somewhere where it has not erupted before. This eruption would likely have characteristics similar to other eruptions in the eastern Snake River Plain, but because these earlier eruptions were essentially “one-off” events they do not dictate where the next eruption will take place.

Low shield volcano that was the source of the Wapi lava flow on the eastern Snake River Plain of Idaho.  Photo my Michael Ort, October 14, 2022.

This type of detailed work performed by geologists is fundamental to our ability to accurately characterize and monitor volcanic hazards. Understanding the linkages between different volcanoes within a geographic area helps scientists to better anticipate where future eruptions may take place and what those eruptions may be like. So, if you find yourself viewing a volcano, whether it be a massive stratovolcano or a small cinder cone, keep in mind that you may not only be looking at a single volcanic vent, but possibly just one piece of a much larger volcanic field.

Posted on

Humpback chub rebound: USGS science uncovers population increase and range expansion for threatened fish

Source: US Geological Survey

A new paper by the USGS and U.S. Fish and Wildlife Service (USFWS) on humpback chub (Gila cypha), a threatened fish species, is showcasing some timely good news. The humpback chub is one of five native fishes still found in the Grand Canyon section of the Colorado River. Due to invasive fishes and other threats elsewhere in the basin, the Grand Canyon population has become essential for long-term persistence of the species. 

The new paper provides model-based estimates of humpback chub abundance over a 15-year period in western Grand Canyon during which river conditions changed dramatically, due to drought and increased water temperatures.

The study reconstructs humpback chub abundance across roughly 200 kilometers of the Colorado River in western Grand Canyon — from Havasu Creek downstream to Pearce Ferry Rapid — between 2010 and 2024.  

The USFWS collected the underlying field data, capturing fish in baited hoop nets and marking them with passive integrated transponder tags. In select years, crews revisited sites to estimate how likely fish were to be caught. USGS scientists then combined those catch and mark-recapture data with expert assessments of habitat quality and a spatial model, allowing them to estimate abundance at the many sites that could not be sampled each year. 

Within this 200-kilometer segment, the results describe a rapid increase in the population, with particular intervals of fast growth. The model estimates that adult abundance grew about 160-fold over the 15-year period, reaching a median of roughly 70,000 adults in 2024. The primary population of humpback chub also shifted westward. More humpback chub are now found in western Grand Canyon, downstream of Havasu Creek, than the Little Colorado River, with the highest densities currently estimated about 210–250 river miles downstream of Lee Ferry. The analysis also offers a modeling approach suited to large river systems where comprehensively sampling every reach isn’t feasible.

Scientists attribute the population increase primarily to warmer water temperatures, a consequence of low reservoir levels in Lake Powell, paired with a current scarcity of warmwater invasive predators in this stretch of river. Pearce Ferry Rapid, an evolving Class VI rapid that formed in 2007, acts as a partial barrier to non-native fishes moving upstream from Lake Mead, likely reducing predation pressure. 

A companion genetic analysis found negligible differences between humpback chub populations found in western Grand Canyon and Little Colorado River, and recaptures show very little movement between the two areas. These patterns are consistent with a once-continuous distribution that fragmented during the cold-water decades. 

While these results document an increase within this one river segment, invasive fishes remain the central concern for the future of humpback chub and other native fishes. Smallmouth bass are associated with steep declines in humpback chub abundances elsewhere in the basin. Due to high elevations of Lake Powell and cool water temperatures, smallmouth bass were extremely rare in Grand Canyon until 2022. 

In 2022, evidence of smallmouth bass juvenile production in Glen Canyon raised concerns that warm water conditions may allow the species to colonize and disperse farther downstream into Grand Canyon. Were this to happen, experience elsewhere suggests humpback chub would become prey to smallmouth bass, which would likely lead to population decline. To date, “cool mix” flow releases in 2024 and 2025 conducted by the Bureau of Reclamation, which are timed to discourage smallmouth bass spawning, combined with mechanical removal efforts led by National Park Service, have appeared to lead to a decline in bass in the areas where they had briefly taken hold.

Humpback chub are one of eight fishes native to the Colorado River historically found in Grand Canyon, and one of the five remaining native fish species still found in Grand Canyon today.  

Humpback chub are endemic to the Colorado River basin, and Grand Canyon has become their stronghold, sustaining the largest of the five remaining populations. The humpback chub population in the Grand Canyon has experienced large changes during the last century. Before the late 20th century, based on archeological evidence and historic records, humpback chub were widespread throughout the Colorado River system.  

After Glen Canyon Dam began operating in the mid-1960s, the river below it cooled sharply. Water that was once warm enough to support spawning became too cold for humpback chub to reproduce, and their population and viable habitat in Grand Canyon contracted. The species persisted largely by relying on a warmwater tributary, the Little Colorado River, for spawning. They were federally listed as endangered in 1967, and by the early 2000s the Little Colorado River population had dwindled to a few thousand fish. By 2021, their population had rebounded somewhat due to warming water temperatures, and they were downlisted to threatened. 

Given the history of this species and these new findings, we now understand that future changes in reservoir operations, water temperature, and the possible downstream spread of invasive fishes could all shape what comes next. Continued monitoring will be key to tracking this expanding group of humpback chub, and can provide information vital to resource managers. 

Posted on

Volcano Minute — Mauna Loa on the move

Source: US Geological Survey

Aloha, it’s your weekly Volcano Minute, brought to you by the USGS Hawaiian Volcano Observatory.

Today, we’re taking a look at how scientists track movement at Earth’s largest active volcano—Mauna Loa.

Each year, the USGS Hawaiian Volcano Observatory conducts a high‑precision Global Positioning System, or GPS, survey across the volcano. These measurements, combined with data from GPS stations that are located permanently across the landscape, allow scientists to monitor subtle changes in Mauna Loa’s shape over time. Some of these locations have been measured for decades, evolving from early leveling techniques to modern GPS instruments.

This summer, scientists surveyed twenty‑two benchmarks on Mauna Loa. Each station requires careful setup of an antenna that is precisely centered over a benchmark on the ground. The device is leveled, and aligned north, often on the rugged terrain of old lava flows. These instruments then record data continuously for several days before being packed up and redeployed with fresh batteries.

The results from this year show a familiar pattern. The summit has moved up and outward, while the flanks have shifted slightly down and away. This indicates ongoing slow inflation beneath Mauna Loa’s summit, consistent with about 2.9 inches of movement per year. Although magma continues to slowly accumulate, seismic activity and gas emissions remain low, and an eruption at Mauna Loa is not expected anytime soon.

Still, these annual measurements are critical. They could help us detect small changes below the surface that could indicate renewed volcanic unrest in the future, supporting our ongoing efforts to keep communities informed.

At neighboring Kīlauea volcano, inflationary summit ground motion indicates that another lava fountaining episode is likely.

Mahalo for listening, I’m Katie Mulliken and this was your weekly volcano minute brought to you by the USGS Hawaiian Volcano Observatory. 

Posted on

Volcano Watch — Watching volcanoes move, one survey at a time

Source: US Geological Survey

Volcano Watch is a weekly article and activity update written by U.S. Geological Survey Hawaiian Volcano Observatory scientists and affiliates. Today’s article is by Research Corporation of the University of Hawaiʻi geophysicist Brianna Corsa. 

Geophysicist sets up a campaign Global Positioning System (GPS) unit over benchmark ELEK, on the northeastern slope of Mauna Loa volcano. USGS photo. 

In addition to a dense network of permanent GPS stations which provide daily positions, HVO also conducts annual campaign GPS surveys to collect high-precision GPS data at benchmark locations across the island. The 2026 annual campaign over Mauna Loa was just recently completed. HVO has been measuring some of these benchmark locations for decades, first with survey techniques like leveling and Electronic Distance Measurement (EDM) and then, starting in 1994, with GPS instruments. 

Mauna Loa is the largest active volcano on Earth and has erupted 34 times since 1843. The most recent eruption occurred from November 27th-December 10th, 2022; initial fissures opened within the summit caldera, Mokuʻāweoweo, and later Northeast Rift Zone vents produced lava flows that extended close to 19 km (12 miles) and covered an area of about16.5 square miles (43 square). Given Mauna Loa’s history of producing large, fast-moving lava flows, it is important that HVO continues to monitor ground deformation on various time scales to understand its behavior.

Data from the campaign survey increases the spatial coverage of the HVO geodetic network and improves our understanding of the long-term deformation field of Mauna Loa, including how the surface changes in response to magma accumulation or migration below the ground surface. For example, motions away from a volcano’s summit might indicate inflation, growth, or rise of the magma reservoir beneath the volcano. GPS positions pointing inwards suggest deflation or migration of magma away from a region. 

Patterns of deformation help prepare scientists for potential hazards, which in turn allows for effective communication of hazards to nearby communities and time for safety efforts to take place. Benchmarks that remain relatively stable through time provide important and reliable ground control points for mapping, calibrating imagery, validating models, and a variety of other research endeavors.

Twenty-two benchmarks on Mauna Loa were surveyed this year, requiring a staged deployment over several days. Each survey set-up consists of a GPS antenna that receives the signals from the satellite, a GPS receiver that records the incoming data, and a tripod, tribrach with an optical plummet, and mounting puck that positions the antenna precisely over the benchmark. 

Displacement field showing the horizontal (red arrows) and vertical (blue arrows) components of motion recorded by Global Positioning System (GPS) positions at each campaign benchmark site from surveys conducted between 2025-2026. The arrows point in the direction of motion and lengths represent how far positions were displaced over the past year. A scale arrow is displayed in the bottom left corner. The highest measured position change was site MLCE on the southeast flank of Mauna Loa, which showed about 5.5 inches (14 cm) of horizontal displacement to the east-southeast, and approximately 3 inches (8 cm) of vertical upward displacement during the past year.

Because we are trying to measure positions with accuracy of a fraction of an inch, it is crucial that the equipment is carefully set up, which can be challenging over varied terrain like lava flows! This means it is important that the antenna is precisely aligned over the benchmark, and that it is level and oriented towards north. The optical plummet in the tribrach allows us to sight down to the benchmark and make the adjustments needed to center the antenna. 

The instruments record data for 3-5 days before the team returns to collect the equipment and then redeploy them at the next benchmark locations with fresh batteries. This window of time is needed for the specialized data processing that we use to produce precise positions. It allows for certain measurement uncertainties to be resolved and reduces the errors due to atmospheric effects.

This year’s survey results align well with trends from the past 10+ years. All benchmarks around the summit moved up and away from their original locations, while several stations on the volcano’s flanks moved slightly down and away. As described earlier, these patterns indicate continued inflation directly beneath Mokuʻāweoweo caldera. Average rate of ground motion at the summit from 2025-2026 is about 2.9 inches/year (7.4 cm/year), consistent with rates from past campaign surveys and those measured at permanent GPS stations from after the eruption in 2022 (see Volcano Watch article from February 26, 2026). 

While Mauna Loa continues to slowly accumulate magma below the surface, seismicity and gas emissions at Mauna Loa’s summit have remained at low, steady levels over the same period, indicating that an eruption is not expected in the immediate future. Nevertheless, HVO scientists continuously monitor deformation to detect subtle changes in activity to provide Hawaiʻi residents with the earliest possible warning of renewed unrest.

Volcano Activity Updates

Kīlauea has been erupting episodically within the summit caldera since December 23, 2024. Its USGS Volcano Alert level is ADVISORY.

Episode 51 of summit lava fountaining happened for 8 hours on July 15. Summit region inflation since the end of episode 51 indicates that another fountaining episode is possible, with current models indicating that it could begin between July 25 and 29. No unusual activity has been noted along Kīlauea’s East Rift Zone or Southwest Rift Zone. 

Mauna Loa is not erupting. Its USGS Volcano Alert Level is at NORMAL.

No earthquakes were reported felt in the Hawaiian Islands during the past week.

HVO continues to closely monitor Kīlauea and Mauna Loa.

Please visit HVO’s website for past Volcano Watch articles, Kīlauea and Mauna Loa updates, volcano photos, maps, recent earthquake information, and more. Email questions to askHVO@usgs.gov. 

 

Posted on

A mid-ocean ridge revealed by 3D magnetic modeling: New geologic map of Escanaba Trough

Source: US Geological Survey

Map of Escanaba Trough offshore of the Oregon/California border.

A new study from USGS and partners uses advanced remote-sensing techniques to provide a high-resolution view of this deep-sea volcanic setting. The research combines new geologic mapping with three-dimensional magnetic modeling to reveal how volcanoes, magma intrusions, and hydrothermal vents formed within one of the world’s few sediment-covered mid-ocean ridges.

A mid-ocean ridge unlike most others

Mid-ocean ridges form the longest volcanic mountain chains on Earth, stretching tens of thousands of miles across the ocean floor where tectonic plates slowly move apart.

Most are relatively free of sediment, allowing volcanic features to remain exposed on the seafloor. Escanaba Trough, however, is different.

Its proximity to the North American continent means that rivers and continental-shelf erosion have buried much of the ridge beneath thick deposits of sediment, creating a distinctive hydrothermal environment where magma-heated seawater interacts with layers of mud and sand, supporting specialized chemosynthetic ecosystems and in some cases leading to the formation of large mineral deposits known as seafloor massive sulfides.  

The autonomous underwater vehicle Sentry being deployed from the research vessel Thomas G. Thompson during the 2022 Escanaba Trough Expedition.

Using multiple remote-sensing datasets collected during a 2022 expedition, researchers developed a new geologic map of Escanaba Trough that allowed them to estimate the volume of volcanic material emplaced below the seafloor and better understand why volcanic activity is concentrated within three distinct volcanic centers at the site.

For the three-dimensional magnetic modeling, the autonomous underwater vehicle Sentry flew close to the seafloor, recording subtle variations in Earth’s magnetic field created by volcanic rocks beneath the sediments.

From these observations, scientists developed six 3D magnetic models that revealed the emplacement and geometry of buried magma intrusions, volcanic structures, and hydrothermal vent systems. These models provide one of the clearest views yet of volcanic plumbing hidden beneath a heavily sedimented mid-ocean ridge.

With the underlying magma bodies revealed, researchers could now better understand why Escanaba Trough’s hydrothermal vent systems occur where they do. Understanding these relationships is important for studying submarine volcanism, mineral formation, and the unique biological communities that thrive around deep-sea vents. The combination of high-resolution geologic mapping and near-bottom magnetic surveys demonstrates how emerging remote-sensing technologies can create detailed models of volcanic systems that traditional seafloor mapping cannot fully resolve.

Read the study, Tectonic Controls on Volcanism and Associated Hydrothermal Activity in a Sediment-Dominated Mid-Ocean Ridge; Escanaba Trough, in JGR Solid Earth.

Posted on

CDI projects highlighted at the Earth Science Information Partners (ESIP) July Meeting

Source: US Geological Survey

CDI projects highlighted at the Earth Science Information Partners (ESIP) July Meeting

A poster about the Community for Data Integration (CDI) at the 2026 Earth Science Information Partners (ESIP) Meeting highlights CDI projects and products.

The Community for Data Integration coordinators are presenting a poster at the Earth Science Information Partners (ESIP) July Meeting. The poster highlights CDI products, including workflows, tools, and guidance documents, that help users throughout the science data lifecycle.

In addition to the project pages linked below, the CDI Data Management Working Group has contributed to several resources on the USGS Metadata Review webpage. 

Related

A reusable Python workflow for the standardized retrieval and alignment of geospatial data

Learn More

Train USGS staff to effectively use Git, GitLab, Python and R within the USGS environment

Learn More

Improve geophysical data management through advancing GS standardization by worked examples, improved functionality and engagement

Learn More

Co-producing adaptable applications and trainings using USGS data to enhance data literacy in K-12 education.

Learn More

Python Hyperspectral Analysis Tool (PyHAT)

The Python Hyperspectral Analysis Tool (PyHAT) provides access to data processing, analysis, and machine learning capabilities for spectroscopic applications. It includes a GUI so you can get straight to analyzing data without writing any code. Or, if you are comfortable writing code, PyHAT can be imported just like any other Python package.

The Python Hyperspectral Analysis Tool (PyHAT) provides access to data processing, analysis, and machine learning capabilities for spectroscopic applications. It includes a GUI so you can get straight to analyzing data without writing any code. Or, if you are comfortable writing code, PyHAT can be imported just like any other Python package.

Learn More

Advancement of GS standard and GSPy software for improved functionality and interoperability of geophysical datasets

Learn More

Enhancing usability of 3DEP data and web services with Jupyter notebooks

We propose to develop a suite of Jupyter notebooks that leverage existing APIs, cloud storage, and open source tools to make it easier for users to efficiently access USGS 3DEP data and to produce data processing and visualization workflows. These notebooks will enhance data utilization, stimulate creative applications, and generate significant return on investment for 3DEP.

We propose to develop a suite of Jupyter notebooks that leverage existing APIs, cloud storage, and open source tools to make it easier for users to efficiently access USGS 3DEP data and to produce data processing and visualization workflows. These notebooks will enhance data utilization, stimulate creative applications, and generate significant return on investment for 3DEP.

Learn More

To help users connect and comprehend USGS data, we propose to develop an interactive viewer for multi-channel geophysical data using existing Python PyViz tools.

Learn More

The purpose of this study is to understand how the USGS is using decision support, learning from successes and pitfalls in order to help streamline the design and development process across all levels of USGS scientific tool creation and outreach. What should researchers consider before diving into tool design and development? Our goal is to provide a synthesis of lessons learned and best

Learn More

Building a Roadmap for Making Data FAIR in the U.S. Geological Survey

FAIR is an international set of principles for improving the findability, accessibility, interoperability, and reusability of research data and other digital products. The PIs for this CDI project planned and hosted a workshop of USGS data stakeholders, data professionals, and managers of USGS data systems from across the Bureau’s Mission Areas. Workshop participants shared case studies…

FAIR is an international set of principles for improving the findability, accessibility, interoperability, and reusability of research data and other digital products. The PIs for this CDI project planned and hosted a workshop of USGS data stakeholders, data professionals, and managers of USGS data systems from across the Bureau’s Mission Areas. Workshop participants shared case studies that

Learn More

Posted on

From source to streams: New national models estimate seasonal nutrients over 21 years in rivers across the U.S.

Source: US Geological Survey

Excess nitrogen and phosphorus in rivers and streams are among the most widespread and costly water-quality challenges globally. Signs of excess nutrients in surface water include eutrophication, harmful algal blooms, ecological degradation, and impacts on drinking water availability. Long-term surface water quality monitoring and modeling are key research areas for the USGS Water Mission Area as we strive to understand how and why water quality is changing. 

The USGS has published new national-scale dynamic SPARROW models, where SPARROW stands for SPAtially Referenced Regression On Watershed attributes. These new dynamic nutrient models predict nutrient loads and sources at a seasonal time step across the streams of the lower 48 states from 2000 through 2020.   In addition to estimating loads from major nutrient sources – including agricultural fertilizers, treated wastewater, and atmospheric deposition, these time-varying models improve previous SPARROW models by estimating lagged nutrient delivery instead of relying on static, long-term averages. The models provide more informative predictions of when and where nutrients enter streams and how they affect water availability.

Lagged nutrients dominate stream loads

The new SPARROW models show that between one-third and one-half of nutrient loads in U.S. streams originated from previous seasons, indicating that historical inputs continue to affect water quality today. Additionally, these lagged, non-point sources of nutrients were the dominant source across the lower 48 states, followed by current season agricultural fertilizers. This highlights why water‑quality improvements often lag behind management actions and why addressing legacy nutrients, along with other non-point and point‑source nutrient loads, is essential for long‑term success.

Nutrient loads and the importance of different nutrient sources, including nutrients left over from past years, shifted throughout the year across the CONUS and in most streams. Spring saw the highest nutrient loads, driven by runoff and newly applied fertilizer and manure, with some regional exceptions such as the Pacific Northwest. Current season fertilizer contributed most strongly in spring and less in other seasons. In contrast, lagged nutrients played a smaller role in spring but became increasingly important through summer, fall, and winter.

The winding road to improvement

Despite reductions in some sources like treated wastewater and atmospheric deposition, overall total nitrogen and total phosphorus loads increased from 2000–2020 across the lower 48 states, driven largely by lagged inputs, agricultural sources and hydrology. Increased nutrient loads pose growing risks to downstream receiving waterbodies and reflect the need for continued nutrient reduction efforts.

Results also indicated widespread areas where concentrations frequently exceeded the National Rivers and Streams Assessment “poor” criteria during 2000–2020 and provide information about the timing and sources contributing to nutrient delivery, which can be used to guide nutrient management efforts. 

Frequency of mean seasonal flow-weighted total nitrogen and total phosphorus concentrations exceeding the US Environmental Protection Agency National Rivers and Streams Assessment “poor” criteria for 2000–2020.

For example, the Midwest region of the U.S. was identified as an area with high nutrient levels. Dominant sources in this area were the lagged delivery of past non-point sources and current agricultural sources. Loads from both sources have increased from 2000 to 2020, resulting in increased loads and yields. However, nutrient concentrations have declined in many places, presumably due in part to increased precipitation and management actions throughout the Midwest during that period. Consequently, despite some improvements in in-stream water availability related to declining concentrations, downstream waterbodies have received increased nutrient loads that can negatively impact water quality and thus availability.

Effective water-quality management typically requires consideration of complex interactions among multiple natural and human factors. These new USGS SPARROW models help pinpoint when, where, and why nutrients are entering rivers, offering a tool for evaluating and protecting water quality across the United States.

Posted on

Happy International Moon Day!

Source: US Geological Survey

Happy International Moon Day!

Join us in celebration of International Moon Day held on July 20, marking the anniversary of the first human landing on the Moon during Apollo 11 in 1969. Our nearest neighbor has made headlines for over 50 years, and still serves as an analog for our present and future pursuit of new knowledge of our Solar System. 

While we didn’t propose International Moon Day, see Moon Village Association (MVA),  we find it an additional avenue to engage our Science, Technology, Engineering and Mathematic efforts. This is in addition to our USGS mission to serve the Nation, the international planetary science community, and the public. With gratitude, we are happy to share International Moon Day and with hopes all are enjoying theirs. 

NASA image AS15-92-12424: Dave Scott’s photograph of Jim Irwin digging a trench to sample the lunar regolith during the second EVA of Apollo 15.  The trench was dug down to the level at which it became much harder to remove. 

Our Past Moon Work: 

USGS Astrogeology contributed significantly to NASA’s Apollo program and has a rich history, originating with our founder Dr. Eugene Merle Shoemaker (aka Gene Shoemaker).  Many Astrogeologists were known to work for and with the USGS Branch of Astrogeology during Apollo and beyond. 

Our overarching collective services included creating detailed maps, helping with landing site selection, providing geologic field training for astronauts, and other cartographic works including image processing and archiving, past work that we still perform today. 

Maps and Landing site selection:

USGS Astrogeology’s goal was to prepare detailed maps to help the spacecraft avoid hazardous terrain, like lava channels, large boulders, and craters that would be hazardous to the lunar module being set down in a safe landing spot, and/or the safety of the astronauts’ first steps on the lunar surface for all humankind. 

Geologic Field Training: 

Gene Shoemaker knew to get the most out of the Apollo missions, the astronauts must learn the language of the stones. Rocks contain information that speaks of the Moon’s origin and more. 

Apollo isn’t just a program of the past, we are modernizing the maps, images, and data to give them a new life in lunar research. Anyone can explore and is welcome to peruse our Apollo data products and maps here: Interactive Apollo 15, 16, and 17 Maps Available Now!

Meanwhile, we have continued to provide astronaut training throughout the years, and we plan for the upcoming  Artemis missions, with similar concerns about landing sites and mapping that the Apollo science teams faced. Detailed investigations like the ones we performed for Apollo are just as prominent as they were 50 years ago. Artemis IV will land in a region of high geologic interest and variability, which is home to potential water-ice deposits. Due to the proximity to the lunar south pole, the potential Artemis landing sites come with their own set of challenges, including high angle shadows and extremely variable temperature and light conditions. 

Posted on

NASA Releases Landsat 10 Spacecraft Request for Proposal

Source: US Geological Survey

NASA Releases Landsat 10 Spacecraft Request for Proposal

The National Aeronautics and Space Administration (NASA) has published a new Request for Proposal (RFP) for the Landsat 10 Spacecraft. Proposals are due August 13, 2026.

July 17, 2026

The Landsat 10 Spacecraft Request for Proposal (RFP) is available for review via SAM.gov as of July 14, 2026. Proposals are due August 13, 2026 at 1:00 PM EDT. 

A new Worldwide Reference System, WRS-3, was developed for Landsat 10 due to the change in orbital parameters.

The final RFP incorporates several updates from the draft version, including further definition in instrument accommodations, mission assurance implementation, mission readiness execution, spacecraft design, observatory level testing, and better alignment with commercial procurement. The RFP also introduces a $1 million incentive for early delivery of the spacecraft. The anticipated contract award and effective date is December 30, 2026, with a period of performance extending through a Launch Readiness Date of no later than December 2031, plus 100 days of nominal commissioning activities. The scope of the contract includes development, integration, testing, delivery of the spacecraft and support through launch and activation activities for the Landsat 10 Observatory. 

The spacecraft will fly in a sun-synchronous orbit at a 653 km altitude—slightly lower than previous missions—with a global revisit time of 18 days to meet stringent signal-to-noise ratio requirements of the Landsat record. To accommodate this new orbit, Landsat 10 will use a new Worldwide Reference System called WRS-3 as a method to acquire, index, and catalog Landsat 10 scenes. Landsat 10 is a Category 2, Class C mission with a design life of 5 years and will include a single integrated suite of sensors called LandIS (the Landsat Instrument Suite).

Under the Sustainable Land Imaging (SLI) Program, Landsat 10 will continue the long-running partnership between NASA and the USGS by acquiring high-quality, space-borne,  medium-resolution global land imaging data. The mission provides key improvements in spatial and spectral capabilities that will allow Landsat 10 to capture land features and trends that could not be detected by previous Landsat missions, while maintaining continuity with the program’s invaluable half-century data record.

Landsat 10 will launch no later than 2031 and continue the Landsat legacy as the longest space-based record of Earth’s land surface. 

Visit the NASA Webpage. 

Return to all Landsat Headlines 

Posted on

Volcano Minute — Will lava flow out of the caldera and, if so, when?

Source: US Geological Survey

Volcano Minute is a weekly audio activity or science update produced by U.S. Geological Survey Hawaiian Volcano Observatory scientists and affiliates.

Kīlauea’s summit is shaped like a series of steps, and the deepest part—Halemaʻumaʻu—collapsed in 2018, creating a large void. Since then, five eruptions between 2020 and 2023 have filled in about a quarter of that space, raising the crater floor more than 1,300 feet, which is about equal to the height of the Empire State Building. Over the past year and a half, the ongoing episodic lava fountaining eruption has added even more lava, bringing the total to roughly 60% of the 2018 collapse now filled. 

If the current eruption continues at the same pace, the volume that collapsed in 2018 could be almost completely filled by late 2027. After that, lava would begin spilling onto the main caldera floor—something we haven’t seen in over 50 years. 

But filling the main part of the caldera will take much longer: many, many years.  

There’s another twist: the active vents are still about 200 feet below the crater rim in Halemaʻumaʻu. If they continue to grow higher and reach above the crater rim, lava could flow downslope out of the caldera and to the southwest, staying within Hawaiʻi Volcanoes National Park and posing no threat to communities. Or, depending on vent geometry, lava could keep filling the caldera. Whichever way lava flows, it will be down the path of least resistance. 

So, the simplest answer to whether lava will flow out of the caldera is: it depends—on how long this eruption lasts, how much lava is produced, and whether new activity starts somewhere else on Kīlauea. 

For now, the eruption at the summit continues. Episode 51 occurred on July 15. More time and monitoring is needed to forecast episode 52 but it’s looking likely within the coming weeks.  

Mahalo for listening, I’m Katie Mulliken and this was your weekly volcano minute brought to you by the USGS Hawaiian Volcano Observatory.