The Caribbean Geophysical and Numerical Research Group
Digits for Earth and Data for Humans
Tropical Storm Jerry is moving up the Lesser Antilles arc to within 220 km. It is closer than expected, but its centre is difficult to identify. The strongest winds are to the east and will not cross any landmass. It is expected to become a Class 1 hurricane once north of the arc on Friday, October 10th evening. The greatest risks are heavy rain and swell.
Caution is advised near rivers and the Atlantic coast.
On Tuesday, September 9, 2025, Dr. Jean-François Dorville was the guest on (local TV channel) Canal 10’s 7 p.m. Focus on Sargassum following the public meeting of the anti-Sargassum collective held in the Petit-Bourg town hall square on Wednesday, September 3, 2025.
For just over 50 minutes, the Sargassum problem was analysed for Guadeloupe, particularly the health effects of anoxic decomposition gases (fermentation).
The reproduction (propagation), growth, and transport of the algae were discussed, as well as their death in Guadeloupe’s coastal waters and their effects. Solutions were presented, both technical and political.
The video of the program is available on YouTube at the following address. Feel free to share it.
An English translation will be available very soon.
TCGNRG was invited by Philippe Petit to speak on Saturday, September 6, 2025, about disruptive solutions and evaluation processes for sargassum management during the political back-to-school session of the Union of Democrats and Ecologists of Martinique (UDEM).
In front of just over 50 people, including politicians, supporters, and curious onlookers, Jean-François Dorville presented the need to analyse our current understanding of the sargassum stranding phenomenon and its consequences, to assess the needs for managing the presence of seaweed on the coast, and to adapt solutions. The three-part presentation, spanning 45 minutes, addressed many interrogation from the audience.
The notion of public health was naturally addressed. The event was held at the “Paradis des Anges” guesthouse in the commune of Vauclin in Martinique. The commune of Vauclin has been particularly affected by the stranding of Sargassum. There was also a persistent smell of Hydrogen Sulfide, due to a strip of manatee grass (Syringodium filiforme) and decomposing Sargassum at the entrance to Pointe Faula (see photo).
After a year 2025 marked by a long period of strandings of holopelagic sargassum, already spanning nearly seven (7) months, the situation on the Guadeloupe coast is complicated.
The solutions implemented (mechanical shovels, sea collection from a barge, and floating barriers to divert or block the algae) appear to be increasingly ineffective and are not adapted to the volumes and frequencies of strandings, nor even to the particularly high sea water temperatures.
Concentrations of hydrogen sulfide (H₂S) and ammonia (NH₃) have been elevated for more than four months.
Dr. Jean-François was invited to this public conference. He was able to speak for a little over twenty minutes and answer questions from a relatively large audience, for a weekday meeting after 7 p.m. Dr. Dorville focused on the current limitations of dams and methods of reoxygenating water and Sargassum sludge to limit toxic gas emissions and mitigate risks to human health and the integrity of copper products, allowing time to better organize the management of stranded algae.
Erin continues its path towards the north-east and northern Europe, leaving the Saharan sandbar that protects the Lesser Antilles diminished in places. Two disturbances are likely to cause heavy rain, to the north from Thursday 21 to Saturday 23 between Guadeloupe and the Virgin Islands and to the south over Trinidad and Tobago between Saturday 23 and Sunday 24.
Erin continues its route and will follow the coasts of North America. It is a major hurricane, it evolves continuously and exposes the islands and coasts to swell (8m in places) and coastal flooding (up to 4m high).
The new atmospheric disturbance is worth monitoring.
Erin class 5 but without direct risk for the Caribbean
Let’s observe our world and dive into its dimensions to understand better the universe that surrounds us
TCGNRG wishes you a happy new year and accompanies you in the observation and understanding of the tropical world
Twenty years after the Saintes earthquake of November 21, 2024, which left one dead, 13 injured, 40 homeless, and above all a large number of disorders on the islands of Saintes, Basse-Terre, and Marie-Galante, looking back on this major event of the last 100 years is important, especially since these disorders are still visible and still impact essential tourist sites for Guadeloupe, such as access to the Soufrière or the second Carbet waterfall.
Two commemorative days are therefore organized in Terre-de-Haut on Friday 22 and Saturday 23 at the Place des Héros in Terre-de-Haut. These days aim to:
read more : AFPS website [in French]
Bernard in Vietnam 2016
These few words will certainly not ease your pain, just as they did nothing to soften my own. But I hope they will help ensure that the memory of this great man endures through the kindness of his actions and the depth of his love.
Meeting Bernard Pottier was a gift for me—a chance to come close to a scientist who, despite all the constraints of the system he had to navigate, managed to keep his convictions, his faith in humanity, and his commitment to clarity and fairness in his explanations. Bernard restored my hope in the academic ecosystem and the beauty of knowledge. Like a true mentor, from our very first meetings, he described to me, in just the right words, the field of possibilities for a geophysicist like myself in the information sciences.
Speaking with Bernard felt like returning to the source, to the very foundation of thought. Never a word out of place, always striving to dispel the darkness of this world. Asking a question of Bernard was like asking a question of a wise cat, who, after a thoughtful twitch of his whiskers, would pounce on the answer with boundless generosity.