Anatomy Of A Seafloor Spreading Event Captured By In Situ Seismogeodesy
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https://doi.org/10.1038/s41586-026-10785-0 <-- shared paper
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https://www.smithsonianmag.com/smart-news/in-a-first-scientists-witness-the-seafloor-spread-in-real-time-giving-them-a-rare-glimpse-at-a-mysterious-geologic-process-180989123/ <-- shared technical media article
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H/T @Seabed 2030
“🔍 For the first time, scientists have observed seafloor spreading in real time.
Seafloor spreading is the process by which new oceanic crust is formed at mid-ocean ridges - a geological process that has shaped entire ocean basins over millions of years.
During a research expedition in the Indian Ocean, scientists had just deployed a suite of instruments when a series of earthquakes triggered a seafloor spreading event, allowing them to observe the process as it unfolded.
The findings offer rare new insights into how new oceanic crust forms and how the seafloor continues to evolve…”
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“Earth’s outermost layer - the crust - is constantly renewing itself. It’s broken into giant chunks called tectonic plates that pull apart, push against or slide past one another, creating grand geologic features.
Underwater mountain ranges, or mid-ocean ridges, for instance, generally take shape where two tectonic plates are moving away from each other. Magma can then bubble up in between, solidifying and turning into new oceanic crust as part of a process called seafloor spreading. Although the phenomenon has created entire ocean basins, it remains quite mysterious because it happens so deep in the water.
Now, for the first time, scientists have observed this dynamic activity happening in real time. They describe their findings - and their stroke of luck - in a study [link above], shedding light on a mechanism that made roughly two-thirds of Earth’s crust…”
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“Over geological time, the growth of the ocean floor involves magmatic and tectonic extension1 at mid-ocean ridges (MORs). Because seismogeodetic monitoring of these submarine plate boundaries remains challenging, little is known about how these systems operate on yearly timescales. Here [the authors] report [on] the first, to [their] knowledge, in situ observation of a rifting event at a MOR segment that combines hydroacoustic, direct-path ranging and bottom-pressure measurements, with repeated seafloor mapping. This event started on 26 April 2024 at the axis of the Southeast Indian Ridge (SEIR) near 37° S, two months after instruments had been deployed across the ridge axis and nearby Amsterdam transform fault (TF). The event began as a rapidly migrating swarm of extensional seismicity along the axial valley. It caused 4 metre of subsidence of the valley floor and more than a metre of horizontal extension across the valley. [They] interpret[ed] this as the deflation of a sill-like reservoir feeding propagating dykes along the ridge axis. The dykes eventually led to the outpouring of about 160 million m³ of lava at the seafloor in about 16 days, while inducing both seismic and aseismic slip on valley-bounding normal faults and finally triggering seismic activity on the abutting TFs. Large-scale aseismic slip induced by magmatic processes could therefore be the primary mechanism by which MOR normal faults accrue their displacement, which would account for their well-documented seismic deficit…”
#Seabed2030 #OceanMapping #Hydrospatial #remotesensing #seafloor #seafloorspreading #oceanic #crust #geology #structuralgeology #IndianOcean #earthquake #midoceanridge #instrumentation #marine #seabed #hydrography #model #modeling #mapping #GIS #spatial #tectonicplates #magma #fortuitous #survey #seismogeodetic #monitoring #submarine #rifting #observation #volcanism #seismicity #dyke #fault #faulting #midoceanridge #MOR