In this animation, frames of NISAR data from
December 2025 to August 2026 show the spread of lava from the northern crater
of Krasheninnikov, a volcano pair on Russia’s Kamchatka Peninsula. In the
image, the lava field appears brighter in the foreground than the surrounding
surfaces.
Credit: NASA’s Scientific Visualization Studio
Like tendrils on a vine, lava
spreads out from the northern crater of Krasheninnikov, a volcano pair on the
Pacific coast of Russia’s Kamchatka Peninsula. On July 30, 2025, an
8.8-magnitude earthquake had struck in the nearby ocean, apparently jolting one
of the two volcanoes awake. A few days later, for the first time in nearly five
centuries, Krasheninnikov started erupting. Since that day, the northern
volcano has been spilling a steady, eastward-flowing field of molten rock and
debris, and the NASA-ISRO Synthetic Aperture Radar (NISAR) mission has been
tracking the changes in the landscape.
From its vantage point 464 miles
(747 kilometers) above the surface, NISAR captured an image of Krasheninnikov on Dec. 25, 2025,
just as the Earth-observing satellite was finishing post-launch checks and
becoming operational. Twice every 12 days since — once as the satellite passed
south to north, and again as it passed north to south — NISAR has returned to
the same spot in orbit and taken detailed radar snapshots.
Researchers put 17 of the frames
captured through mid-August into sequence, forming a time-lapse video that
shows lava filling a smaller, inner caldera, then overflowing into a wider
crater before widening into a fan. The animation highlights how NISAR’s
observations can monitor the development of natural hazards, both for science
and potentially for emergency response.
Though remote, many of Kamchatka’s
dozens of volcanoes are closely monitored with ground instruments because they
erupt frequently. Not so with Krasheninnikov, which has been quiet since about
the year 1550. That NISAR’s L-band radar observed it at all speaks to the
satellite’s near-global coverage of the planet’s land surface at resolutions in
the dozens of feet; that it captured the erupting volcano over time shows the
precision and reliability of its measurements.
“The consistency is crucial. Twice
every 12 days, acquiring in this high-resolution mode and in two observation
directions, this shows the promise of NISAR to closely monitor natural
hazards,” said Matthew Pritchard, a member of the NISAR science team and
geophysicist at Cornell University who analyzed the data used to create the
animation.
Images from microwaves
The detail in a single NISAR image
results from the use of synthetic aperture radar, or SAR, a specialized
processing technique pioneered by NASA’s Jet Propulsion Laboratory in Southern
California for Earth observation from space. As the satellite orbits, the radar
sends thousands of microwave pulses per second to Earth and receives the return
signals, each of which is effectively a snapshot in time that contains
information about the properties and characteristics of the surface below.
The SAR processing combines the
many images of the same area, sharpening the view just as a lens brings a
blurry object into focus. Each pixel in the individual frames of the
Krasheninnikov time-lapse represents about a 30-foot-by-30-foot (10-meter-by-10-meter)
square on the surface — about half the size of a tennis court.
Lava shows up lighter in the images
due to the way that microwaves reflect more brightly compared with the
surrounding surface, which, depending on the time of year, is either snow or
bare ground. In addition to the lava field growing to the east, the video shows
another flow to the northwest, one that likely formed before NISAR captured the
first NISAR image.
When Pritchard was doing his
doctoral research on Kamchatka volcanoes more than 20 years ago, analysis-ready
radar data was difficult to come by, both because satellites didn’t revisit as
often and the resolution of the images was relatively low.
Now in addition to getting frequent
and comprehensive coverage of virtually all the planet’s roughly 1,300 active,
above-sea-level volcanoes, the images are sharp down to the several-meter scale
and are easily accessible via the cloud.
“We’re seeing volcanoes around the
world that we’ve never really had eyes on like this before,” said Pritchard.
The NISAR satellite is the first
free-flying space mission to feature two radar instruments: an L-band system
and an S-band system. The systems are complementary due to their differing
wavelengths. For example, the longer-wave L-band can pass through tree
canopies, imaging the ground beneath. Meanwhile, depending on leaf sizes,
S-band can collect observations of those canopies.
The data products from the NISAR
mission’s L-band radar are available at the Alaska Satellite Facility
Distributed Active Archive Center in Fairbanks, which hosts and distributes all
NASA synthetic aperture radar data.
More about NISAR
Managed by Caltech for NASA, JPL
leads the United States component of the project and provided the satellite’s
L-band SAR and antenna reflector. The spacecraft bus and its S-band SAR were
provided by ISRO (Indian Space Research Organisation).
The NISAR satellite is the first to
carry two SAR instruments at different wavelengths, collecting data using the
spacecraft’s giant drum-shaped reflector, which measures 39 feet (12 meters)
wide, which is the largest radar antenna reflector NASA has sent into space.
To learn more about NISAR, visit: https://science.nasa.gov/mission/nisar/
Source: US-India Satellite Captures Time-lapse Video of Volcanic Eruption - NASA


