Hurricane Melissa and “Maya blue” off Jamaica: satellites captured a rare geophysical sight after a devastating storm
Hurricane Melissa, which struck Jamaica on October 28, 2025 as a Category 5 storm, left behind images of destruction on land — but also an unexpected “signature” at sea. A few days after landfall, satellite images showed a vast area of the Caribbean Sea tinted an unusually bright, almost milky blue. According to an analysis by scientists who track ocean dynamics from space, this was one of the most striking episodes of carbonate-sediment resuspension recorded in the satellite era.
Devastating impact: record strength and a long recovery
According to the U.S. National Hurricane Center (NHC), at landfall in southwestern Jamaica Melissa had estimated sustained winds of 185 miles per hour (295 km/h) and an exceptionally low central pressure of 892 millibars, placing it among the strongest hurricanes recorded at landfall in the Atlantic basin. The storm moved slowly, bringing destructive wind gusts, storm surge, and heavy rainfall, which, combined with the terrain, triggered flooding and landslides.
In the days after the storm, Jamaica’s civil protection services and international humanitarian organizations reported extensive damage to homes and infrastructure, and thousands of people who temporarily had to leave their homes. Official statements from Jamaica say that tens of thousands of damage assessments were carried out, and the scale of damage to buildings is measured in hundreds of thousands across different levels — from partial roof damage to complete collapse. In bulletins from humanitarian organizations and in statements by the competent services, the same message was repeated: recovery will take time, and priorities are temporary shelter, repairs to key roads, and the restoration of basic services such as electricity and water.
On land, alongside the rebuilding of houses and public buildings, questions also arose about how damage to agriculture would affect food supply and prices. Public assessments from Jamaica and international reports point to a wide range of consequences: from lost crops and damaged irrigation systems to livestock losses. Part of the burden was borne by rural communities in the southwest, where winds and storm-driven flooding were most destructive, and access to some areas was hindered for days due to landslides and flooded roads.
A sea-side sight that surprised even experienced observers
While impacts were being tallied on land, Melissa also left a mark on the open sea before striking Jamaica. According to NASA Earth Observatory, the hurricane lingered for days south of the island and powerfully “mixed” the water column above a shallow submarine plateau known as Pedro Bank. Two days after landfall, when a brief cloud-free window opened, the MODIS instrument on NASA’s Terra satellite recorded a dramatic change in sea color: a vast area turned light blue due to sediment lifted from the seafloor.
Scientists describe such phenomena as large-scale natural “experiments” — events impossible to reproduce in a laboratory, but trackable by satellites. That is why these images are not only visually striking; they carry data about currents, eddies, and ocean mixing that affect ocean chemistry and the global carbon cycle.
What is Pedro Bank and why it matters
Pedro Bank is a large, shallow marine area south and southwest of Jamaica, with a range of sandy and coral formations and seagrass meadows. Such shallow “banks” are important both ecologically and economically: they are known as habitats for many species and as fishing grounds, including commercially important areas. At the same time, Pedro Bank is described as a carbonate platform — an environment where fine particles of calcium carbonate (CaCO3) accumulate on the seafloor, often formed by the breakdown of shells and skeletons of marine organisms and then reworked by waves and currents.
Under “normal” conditions, Pedro Bank is barely visible in natural-color satellite imagery, because it is covered by a layer of water and because the sediment is bound to the bottom. But strong and prolonged wind stress, as well as waves generated by a hurricane, can lift this fine material into the water column. It is then that the water takes on a characteristic, bright shade different from the greenish-brown tones typically produced by river plumes after heavy rains: while river sediment often carries a mix of minerals and organic matter from land, here carbonate “mud” associated with the marine plateau dominates.
“Enormous mixing power”: how large the sediment cloud was
James Acker, a scientist providing data support at NASA’s Goddard Earth Sciences Data and Information Services Center, told Earth Observatory that Melissa had “enormous mixing power” over the water column in the Pedro Bank area. Comparing it with previous storms, he noted that Hurricane Beryl in July 2024 caused some brightening around the plateau, but “nothing like this.” In scientific terms, that set the frame for what followed: an extreme, but exceptionally informative signal in ocean color.
Sedimentologist Jude Wilber, who tracked the movement of the “plume” using multiple satellite sensors, estimated that on October 30, 2025 suspended sediment was visible not only over Pedro Bank but also over other nearby shallow areas. By his estimate, about 37,500 square kilometers were affected — more than three times the area of Jamaica. Wilber, who has studied carbonate-sediment transport for decades, believes the Pedro Bank event may be the largest of its kind observed in the satellite era.
Sediment as a “tracer”: what currents reveal themselves through blue color
The temporary change in sea color is not just an aesthetic anomaly. In oceanography, suspended sediment often acts as a “tracer” — a natural marker that reveals the pathways of surface currents and eddies. In an analysis for NASA, Wilber stated that part of the pattern extended into the flow field of the Caribbean Current, which runs westward and northward, while other parts suggested the influence of wind-driven Ekman dynamics, a process in which wind and Earth’s rotation cause net transport of surface waters at an angle relative to the wind direction.
Scientists also recorded additional complexities. The southern branch of the blue cloud, according to NASA Earth Observatory’s description, split into three parts after encountering several smaller reefs. In the eastern branch, where sediment began to settle, a “staircase-like” pattern was observed, suggesting cascading particle sinking and layered mixing. Such details, though seemingly minor at first glance, are valuable to researchers because they show how seafloor microrelief and local reefs can “break up” the signal and redirect flows.
How long the “blueness” lasts and what remains after the water clears
In such episodes, the sea color usually returns to its usual tones within a few days. According to NASA Earth Observatory, at Pedro Bank the brightening gradually disappeared after about a week, as sediment settled back to the bottom. This is also a reminder that satellite images, however impressive, capture a moment in a dynamic process that can change quickly.
But the impact on the seafloor itself can be longer-lasting. Wilber warned that Melissa may have been so strong that it caused what he describes as a “wipe” — a kind of “erasure” or devastation of the benthic ecosystem on the bank. Seagrasses, algae, and other organisms living on and around the bank may have been significantly damaged, and the pace and pathway of community recovery are not yet clearly predictable. In practice, recovery depends on a range of factors: from the availability of larvae and seeds, through substrate stability, to the frequency of new disturbances during the storm season.
Why this event matters for the global carbon cycle
The broadest implications of such episodes relate to how oceans store carbon. Carbonate sediments carry carbon bound in calcium carbonate. When strong tropical cyclones lift sediment from shallow areas, some of the material can end up in deeper waters, where carbon can potentially be retained for longer periods. In deeper layers, carbonates can also dissolve, which is another important process in the marine carbon system. The scientific value of such episodes lies in enabling the tracking of particle “paths”: from a shallow plateau, through surface flows, to potential deposition in deeper seas.
In recent years, satellites have enabled near-continuous monitoring of the ocean, so such events can be compared and quantified. Acker and colleagues developed remote-sensing methods to estimate how much sediment, after storm-driven mixing, reaches the deeper ocean, including analyses after Hurricane Ian over western Florida. The Pedro Bank event, as described by NASA, provides a rare opportunity to test these procedures on an extreme case, in a situation where the ocean-color “signal” is strong enough to be clearly separated from background variations.
The role of new satellites: PACE and a “hyperspectral” view of the sea
NASA emphasizes that in the coming years even more precise monitoring of ocean color is expected thanks to the PACE mission (Plankton, Aerosol, Cloud, ocean Ecosystem), launched in February 2024. PACE carries the Ocean Color Instrument (OCI), an advanced optical spectrometer that measures light in finer wavelength steps than previous sensors, enabling more detailed separation of signals from plankton, dissolved substances, and different types of suspended particles.
For scientists, this means better estimates of the concentration and spread of carbonate mud, a clearer picture of how the cloud expands and where it settles, and stronger links to the meteorological and oceanographic conditions that determine the outcome. In practical terms, such data can also help regional understanding of sensitive shallow areas — not only from an ecosystem perspective, but also from the viewpoint of fisheries and marine spatial management, because changes on the bottom can affect habitats and resource availability.
Between the human cost and the scientific value of a “natural experiment”
Scientists insist on the dual reality of such events: for people on land it is a catastrophe and a long recovery, while for science it is a rare opportunity to see in real time how extreme atmospheric energy reshapes the sea. In NASA’s text, Acker stressed that the “human cost of the disaster” must always be acknowledged, but he also emphasized that the scene above Pedro Bank is an “extraordinary geophysical sight.”
Ultimately, the cloud of bright-blue sediment in the wake of Hurricane Melissa shows how tightly oceans and the atmosphere are linked: one storm can, in a matter of hours, change the appearance of the sea over an area larger than an entire country, shift sediments that have been accumulating for decades, and raise new questions about the recovery of marine habitats and the role of tropical cyclones in the global carbon cycle. While Jamaica and the region continue to cope with the storm’s impacts on land, the scientific community has gained a rare “window” into processes that usually unfold hidden beneath the surface.
Sources:- NASA Earth Observatory / NASA Science – article and satellite imagery “A Plume of Bright Blue in Melissa’s Wake” (MODIS/Terra, Pedro Bank, statements by Acker and Wilber) (link)
- NOAA / National Hurricane Center – Tropical Cyclone Update (October 28, 2025; wind 295 km/h, pressure 892 mb, landfall location) (link)
- UN OCHA – Jamaica: Hurricane Melissa Situation Report (summaries of impacts on infrastructure and the humanitarian situation) (link)
- World Bank / GFDRR – Global Rapid Post-Disaster Damage Estimation (GRADE) Report for Jamaica (estimates of direct damage and sectoral breakdown) (link)
- Jamaica Information Service (JIS) – official releases on building and housing damage assessments after Hurricane Melissa (ODPEM/press briefing) (link)
- Jamaica Information Service (JIS) – preliminary assessments of agricultural damage (Ministry of Agriculture; scope of affected areas and livestock) (link)
- USDA FAS – report on the impact of Hurricane Melissa on Jamaica’s agricultural sector (loss estimates and risks to food supply) (link)
- NOAA National Ocean Service – educational material on the Ekman spiral and wind-driven surface-water dynamics (context for “Ekman transport”) (link)
- NASA – PACE mission (launch date and goals) (link)
- NASA PACE – Ocean Color Instrument (OCI) (description of hyperspectral ocean-color measurements) (link)
- Marine Planning – overview of the Pedro Bank area (location, ecological and economic significance) (link)
Find accommodation nearby
Creation time: 14 hours ago