Saturday, December 9, 2023

Images of the week : marine maps created by AI


It's amazing to see the results of GPT4 / DALLE3 (Bing Image Creator) when you ask it to make nautical raster maps, bathymetry maps or vector nautical maps.
Some example of responses are shown above : of course nothing scientific or accurate about it but very imaginative though.

Friday, December 8, 2023

High-amplitude internal waves, generated at the Camarinal Sill, propagate eastward through the Strait of Gibraltar.

From Eumetsat by Marina Bolado-Penagos, Águeda Vázquez, Miguel Bruno, Aida Alvera-Azcárate, Noemi Marsico, Ben Loveday
High-amplitude internal waves, generated at the Camarinal Sill, propagate eastward through the Strait of Gibraltar.
These waves, which effect surface roughness, can detected by both radar and optical satellite missions.

What are internal waves and why do we care about them?

Waves on the sea surface are a familiar phenomenon for anyone who has sailed or been to a beach. However, waves also occur in the depths of the oceans. 
They are the result of changes in density of ocean waters, as a result of variable water temperatures and salinity. 
They play a crucial role in how energy is transferred in the ocean and can affect the movement of nutrients and other essential chemical species, including those related to the ocean carbon cycle.
Internal waves can reach scales of over 100m vertically and, as a result, are a concern for underwater operations, eg by submarines.
They can have very little surface expression, especially compared to their scale at depth, however, they have also been associated with interesting features by sailors, including 'dead water'.
Internal wave generated in the Strait of Gibraltar?

In the region near the Strait of Gibraltar, where the Atlantic Ocean meets the Mediterranean Sea, there is a complex interaction of different water mass layers.
The lighter, upper layer of water, derived from the Atlantic, flows eastward into the Alboran Sea in a twisting current, known as the Atlantic Jet.
This current undergoes seasonal changes and plays a significant role in the upper layer dynamics of the region.
The more dense and salinated Mediterranean water flows westward at greater depths towards the Atlantic Ocean.
This interaction in the Strait of Gibraltar is often simplified as a two-layer exchange, and it creates a region called the Atlantic-Mediterranean Interface (AMI).
The AMI is warmer, more shallow, with higher salt levels, on the eastern side of the Strait than on the western side.

The AMI is subject to different coastal and sea-floor influences at different levels.
In the upper layers, the flow of Atlantic water is controlled by the narrowest part of the Strait, called the Tarifa Narrows, where the AMI is thicker.
The outflow of Mediterranean water is controlled by certain underwater sills or ridges in the Strait, especially the Espartel and Camarinal Sills.
The Camarinal Sill has been extensively studied, because it generates large waves beneath the surface, known as High Amplitude Internal Waves.
These waves form when the strong westward tidal currents pass over the Sill, creating an internal wave on the lee side of the ridge.
They remain near the Camarinal Sill for about three hours, until the water flow slows down, after which they mostly move eastward into the Mediterranean Sea.

Internal waves are studied using a dimensionless number called the internal Froude number (G2), which takes into account the average velocity, density, and thickness of the layers where internal waves form. Internal waves stay trapped at the Sill when this number equals or exceeds one, and are released when it is lower than one.
Even though these waves are created deep underwater, they can also be seen from space, because they effect the sea surface roughness.
This is visible in radar and optical imagery. Satellites have tracked these waves within the Alboran Sea as far as 200km from the Camarinal Sill (35.93 N, 5.75 W), showing that they can persist up to 50 hours after they start moving.
Do these internal waves always move at the same speed?

The answer is no. The speed at which they travel can change, based on different factors.
These include: how the water is layered in terms of density; the direction of winds (east to west or west to east), and the strength of tides or currents.
The tidal cycle influences the energy of these wave processes, and, while the most energetic waves occur during spring tides, a less intense process happens during neap tides.
During spring tides the very powerful process causes significant vertical movement of water layers, with changes in current speed, and neap tides involve moderate vertical water movement and less disturbance in current speed.

Vázquez et al. (2008) observed that the generation of High Amplitude Internal Waves often depends on the condition of flows which are primarily influenced by changes in atmospheric pressure over the Mediterranean region.
As a result, the occurrence of internal wave events can be suppressed or triggered depending on the specific weather conditions over the Mediterranean.
Recently, Bolado-Penagos et al. (2023) confirmed that atmospheric forcing must be taken into account along with the tidal cycle to characterise the travel time of internal waves towards the Mediterranean.
They observed that those waves took between 14 and 20 hours to reach the northwest of the Alboran Sea.
In terms of speed, this means that the internal waves were moving at a rate of approximately 0.9 to 1.3ms-1.
Estimating wave speed from Sentinel-1 SAR-C and Sentinel-3 OLCI

In this case study, the presence of an internal wavefront on 14 May 2023, is observed using images from the Copernicus Sentinel-1 SAR-C (synthetic aperture radar) sensor and Sentinel-3 OLCI (optical) sensors.
From the Sentinel-1 radar image (shown in the left side of Figure 1), we can see the presence of the wave train to the east of the Strait of Gibraltar.
This front was detected at 06:28 AM, while Sentinel-3 OLCI captured the same train at 10:49 AM (Figure 1, right panel).

Sentinel images comparison : Sentinel-3
Figure 1: Internal wave patterns in the Eastern Strait of Gibraltar, as extracted from Sentinel-1 SAR-C and Sentinel-3 OLCI on 14 May 2023. Left panel contains modified Copernicus Sentinel-1 data 2023, processed by Sentinel Hub EO-Browser.

From the optical OLCI imagery, it is evident that waves disperse as curved wavefronts when waves enter the Alboran Sea, due to the effects of diffraction and tidal advection processes.
But when did these waves originate?
Were they released from the Camarinal Sill?
It is worth noting that changes in surface roughness are often hard to detect in optical imagery, but they are often most visible in the 'glint' patterns that occur on the eastern edge of images, as shown in our example.
Usually, glint makes ocean colour data hard to work with, but in this case, it is actually helpful to us!

According to the methodology by Bolado-Penagos et al. (2023), these waves would have been released from the Sill around 18:45 PM on 13 May, by the time that the internal Froude number is lower than one (Figure 2a).
This estimation is calculated from the tidal current prediction over the Camarinal Sill at 45m depth (Figure 2b). 
Figure 2: (a) Internal Froude number (G2) estimation based on the (b) tidal current prediction (m s-1) over the Camarinal Sill at 45 m depth (Vázquez et al., 2008).
The horizontal black line delimits the positive/negative current directed toward the Mediterranean/Atlantic side.
The vertical gray rectangle indicates the time during which the internal waves would have been released (13 May 2023, 18:45 UTC).
Credit: Marina Bolado-Penagos, GHER.

The wavefront seen in the Sentinel-1 image (Figure 1, left hand side) is located around 50-55km from the Camarinal Sill.
This is observed about 12 hours after the possible release of these waves (Figure 2).
As a result, the travel speed of this front would be around 1.2ms-1.
This speed aligns with less energetic tide conditions (neap tides) and the presence of strong easterly winds in the area.
Regarding the propagation speed of internal waves within the Alboran Sea, it depends on the stratification of the area.
In less than four hours, the wave train now detected in the Sentinel-3 image (Figure 1, right hand side) appears to have travelled a distance of 20km, which implies a propagation speed of approximately 1.4ms-1.
Links :

Thursday, December 7, 2023

France & misc. (SHOM) layer update in the GeoGarage platform

158 nautical raster charts updated (including 13 new editions whose example above with chart 7143)
Litto3D SHOM

Greenland’s melting glaciers spew a complicated treasure: sand

Sand is building up on Greenland's coast, carried by water from the melting ice sheet.
It's an exceedingly valuable resource.
Photograph: Nicolaj Krog Larsen

From Wired by Matt Simon
Greenland’s Melting Glaciers Spew a Complicated Treasure: Sand
Meltwater from the island’s ice sheet is loaded with the right kind of sand for concrete production—which further warms the planet.

Sand is both abundant and rare.
Earth has vast deserts of the stuff, of course, but not the kind that’s in such high demand that sand mafias are killing for it.
That special variety is a critical component of the concrete used in buildings and infrastructure, the production of which has skyrocketed exponentially over the last few decades.
That has come at a significant climate cost: The industry now accounts for 8 percent of global carbon emissions.

Sand is also at the center of a strange climate story.
Climate change is destroying Greenland’s ice sheet, producing an extraordinary amount of meltwater.
(Even if we somehow totally stopped emissions today, Greenland’s melting could still contribute nearly a foot of sea-level rise.) And in a twist of fate, that meltwater is loaded with the right kind of sand for concrete production, which causes more warming and more melting.
Great plumes of glacial sediment are swirling along the coast, actually adding land along the edges of the island.
Even though Greenland is only three times the size of Texas, its ice sheet is the source of 8 percent of suspended river sediments flowing into the oceans.

The country now has to figure out whether exploiting that valuable, abundant resource on a wider scale would be environmentally, socially, and economically tenable.
“It is quite controversial—we're saying Greenland can benefit from climate change,” says Mette Bendixen, a geographer at McGill University in Canada, who’s studying the idea.
“Contrary to most of the other parts of the Arctic coast, Greenland is not eroding.
It's in fact growing bigger, because the ice sheet is melting.
So you can think of the ice sheet as a tap that pours out not only water, but also all the sediment.”

Greenland is actually growing as an island, thanks to all that sediment.
Photograph: Nicolaj Krog Larsen

That sediment is special, indeed.
Desert sand from, say, the Sahara is no good for making concrete because it’s too rounded and uniform.
Over millennia, winds push those grains around, polishing them.
If you make concrete out of such sand, “it's almost like building with marbles,” says Bendixen.
“You want particles that are more angular in shape, not rounded.
And that type of material is exactly what you get from rivers, for example, or material that has been deposited by glaciers.”

As Greenland’s ice sheet—which covers 700,000 square miles and is up to 10,000 feet thick—rubs against the land, it grinds up sediment, including sand, fine silt, and larger chunks of gravel.
And as the ice melts, torrents of water carry all that debris to the sea, while the pounding of the rivers themselves further erodes the landscape.
Compared to the thousands of years that sand spends rolling around the Sahara and becoming rounded, the particles coming off Greenland are fresher.
They’re more angular and more diversely shaped.
Instead of acting like marbles, they fit together like pieces of a jigsaw puzzle, which is good for concrete.

Photograph: Nicolaj Krog Larsen

Greenland already harvests its sand for local, small-scale concrete production, since importing sand would be prohibitively expensive.
This is limited to domestic companies, who have to win non-exclusive permits after passing environmental review by the government’s scientific advisers.
They can also apply to export the sand, but that requires additional licensing.
“We are basically also open for sand extraction aiming at export, but then it will be treated like any other mining activity,” says Kim Zinck-Jørgensen, of the Greenland government’s Mineral Licence and Safety Authority.
“And for that you'll have a much greater setup with regulations and also environmental impact assessments, social impact assessments.”

Currently, dredging boats suck up sediment along the coast and filter out the sand, which is then brought back onshore.
But if Greenland decides to scale up sand extraction for export, that would mean big ships would have to haul the stuff away to international ports.
“It's important to stress that if you extract whatever natural resource, there will be environmental consequences,” says Bendixen.
“But really, here the environmental consequences can be super broad.”

For one, those big ships will also be bringing in ballast, or the water they’ve collected from elsewhere and stored in their hulls for balance.
If that ballast is released off the coast of Greenland, it may introduce invasive species.
And, of course, dredging coastal sediments would further endanger underwater native creatures—and on land, increased mining operations might scare away the game that Inuit hunters rely on.
(Greenland’s population is about 90 percent indigenous Inuit.
The Greenland branch of the Inuit Circumpolar Council, an NGO representing Inuit peoples, declined to comment for this story.)

Interestingly, though, last month Bendixen and her colleagues published a survey of Greenlanders about their opinions on sand extraction.
They found that 84 percent of adult residents are in favor of it, and three-quarters want it to be a national project.
“It turns out that the vast majority of Greenlanders think that it should be primarily a Greenlandic enterprise,” says Rasmus Leander Nielsen, a political scientist at the University of Greenland, who did the survey with Bendixen.
“Maybe you could have some smaller-scale, Greenlandic-led companies that could start off.
And then eventually, when the business case is more favorable, then we could go into a larger export.”

About that business case: While the global demand for sand has gone wild, the economics of exported Greenland sand aren’t yet clear.
A company would have to pay to run the local operations and foot the shipping costs to get the resource off the island.
Those will be considerable, since sand is heavy and takes up a lot of room in a ship.

The Greenland government recently worked with a consultancy that did an assessment, finding that exporting the sand to Europe isn’t economically feasible at the moment.
“Whether it's feasible to export it further on to the Middle East, I don't know,” says Thomas Lauridsen, chief adviser to Greenland’s Ministry of Mineral Resources and Justice.
“But we will then be in competition with European companies that will dredge sand in Europe or closer to the customer.”

Lauridsen adds that it’s up to the private sector to determine whether selling Greenland’s sand is cost-effective or not.
And that export cost calculus may change in the future.
“By 2100, the demand for sand is going to rise 300 percent, and the price 400 percent,” says Bendixen.
“So we don't have to look that much farther into the future to start seeing a different calculation here in terms of whether it's worthwhile.”

Yes, a world with more sand harvesting for making more concrete would also mean more carbon emissions, more warming, and more melting of Greenland’s ice sheet.
But, Bendixen says, all that glacial sand need not go exclusively toward concrete.
Coastal communities are increasingly clamoring for sand to hold back rising seas, a fortification known as beach nourishment.
“Just think of the irony in using the sand for beach nourishment to mitigate sea-level rise,” says Bendixen, “which is caused by—to a large extent—the melting of the Greenland ice sheet!” 

Links :

Wednesday, December 6, 2023

Primar reaches milestone proposing more than 20,000 vector nautical charts in the ENC world catalogue

Worldwide coverage
20,034 ENC from scale 1:500 to 1:20,000,000 
download the weekly updated kmz file from the GeoGarage platform
for visualizing worldwide ENCs of the Primar catalogue with the Google Earth application
NO6H0921 Oslo (scale 1:3,500)
last brand new ENC produced (28/11/2023 edition : 1)

Today marks a significant milestone as Primar released the twenty thousandth ENC cell.
The PRIMAR database now proudly houses 20,034 ENC cells
note : 633 cells have been replaced and/or withdrawn since 2004-02-22
IHO membership :
in green IHO member states / in yellow Non member coastal state
79 international IHO Hydrographic Offices in the Primar catalogue 
but a couple of Hydrographic Offices (available in the AVCS Admiralty catalogue) are missing :
  • LK - Sri Lanka : 7 ENCs
  • MM - Myanmar : 4 ENCs
  • TH - Thailand : 40 ENCs
For info, it's worth noting that some countries don't deliver the same data to Primar and UKHO 
Ex.: (Primar vs AVCS UKHO)
- Indonesia ID (539 vs 581 cells including 56 less / 14 more) ...
- China CN/C1 (504 CN vs 41 CN cells but 0 C1 vs 499 C1 cells)
- Vietnam VN/V1/V2 (72 V1 vs 4 V1 cells / 13 VN vs 0 VN cells / 0 V2 vs 44 V2 cells)
By the way, some GB ENCs (97 cells) created with mixed copyrights between UKHO, and other international Hydrographic offices or organisms are not available in the Primar catalogue.
Actually, UKHO receives ENCs from IC-ENC and PRIMAR RENCs but also directly from national hydrographic offices who do not want to distribute their ENCs via a RENC (Primar or IC-ENC), and provides ENC services for the end user.

From 2020 to 2023 : more than 3,000 new ENC (17,000 to 20,000)
Note : the GeoGarage platform is an official Primar ENC distributor especially for onshore applications (so not for SOLAS navigation) used in a local network solution for some limited number of concurrent users in a closed environment.

Links :

From seabed to cloud: ground-truthing seagrass data

From Hydro by Guy Rigot, Raja Kandukuri 
Adding credibility and scalability to the blue carbon market

The ocean plays a crucial role in mitigating climate change, yet we lack detailed information on over 95% of the seafloor.
This article explores planblue’s solution to accelerate time-to-data and the accuracy of seabed mapping, showcased by several successful case studies.
Planblue’s technology combines underwater hyperspectral imaging, RGB imaging and underwater navigation with an AI-driven automated data processing pipeline.
Overcoming challenges relating to geolocation, water column distortion and motion distortion, planblue’s data products add credibility to the blue carbon market.

70% of the Earth’s surface is covered by the ocean, which regulates the climate, absorbs carbon dioxide, provides food and supports biodiversity.
The seafloor, as far as we know, is the best carbon sequester available, and can fix CO₂ up to 30 times faster than trees on land.
Notably, seagrass exhibits remarkable CO₂ capture efficiency.
Despite their pivotal role in mitigating climate change, seagrass meadows face inadequate recognition and protection due to limited data on their distribution.
They are heavily underrepresented in policy-making and finance decisions around climate mitigation.
In fact, of all the United Nations Sustainable Development Goals, Goal 14 ‘Life below water’ has received the least amount of public money.
To tap into the large carbon sequestration potential of the ocean, we need to finance projects for seafloor restoration and preservation.
Access to credible data is essential to accelerate the blue carbon market, including blue carbon credits and Nationally Determined Contributions (NDCs) to meet the Paris Agreement.
Mapping the seafloor and measuring carbon

Planblue was founded in 2017 by two former marine scientists and two engineers to enable high-quality seafloor mapping, inspired by satellite technology.
Based in Bremen, Germany, the company now has over 25 employees.
Using a novel seafloor mapping solution, planblue processes seafloor data from around the globe with the explicit goal to highlight the ecologic and economic value of the seafloor.

Replacing traditional seafloor mapping methods with highly automated and scalable processing pipelines, planblue can produce georeferenced seafloor maps at pace.
Its goal is to add in-depth information to bathymetric maps, including the health state of the seafloor, carbon sequestration potential, biomass and biodiversity.
The technology is capable of surveying anything on the seabed and mapping a variety of carbon sequestering ecosystems, including corals and seaweeds.
For its first application, planblue has focused on seagrass meadows.
Speed and scale

As the world is running out of time to turn the tide on climate change and protect biodiversity, an important part of planblue’s mission is to provide speed and scale for the protection of vital ecosystems, replacing manual processes with automated pipelines based on state-of-the-art computing and AI.
Traditional methods of ground-truthing aerial and satellite data require a time-intensive process of in situ collection of core samples from the seafloor and subsequent lab analysis.
Planblue’s technology largely replaces this with near in situ remote sensing, using hyperspectral cameras and a selection of sensors to correct distortions of the images in the water column.
As planblue controls the entire data chain, it can ensure a seamless and speedy process, even in areas with limited internet access during field campaigns.
By implementing these streamlined processes, planblue can reduce time-to-data from weeks or sometimes months to days or even hours.

DiveRay mapping seagrass near Bodrum, Turkey.
(Image courtesy: planblue GmbH)

Measuring Mediterranean seagrass

Normalization of data is essential to meaningfully compare results over time, between locations or with other remote sensing technologies.
Since planblue started six years ago, its technology has been tested and improved through several campaigns around the world.
This article zooms in on two crucial surveys in the Mediterranean, in France and Turkey.
In October 2022, planblue first tested a selection of new sensors in Nice, France, that were added to increase the accuracy of the AI and other algorithms.
The survey in May 2023, east of Bodrum in Turkey, gave a unique opportunity to compare the outcomes of the algorithms with the manual measurements collected at the location over the past years and with the data from the Nice campaign.
A new dimension to seafloor mapping

With the ambition to create a comprehensive representation of underwater areas and their changes over time, the first step for planblue is the creation of orthoimagery of the seafloor.
Through its automated pipelines, planblue’s technology can stitch thousands of images together in less than 24 hours after the seafloor data has been collected.
Underwater navigation and geolocation are however essential for accurate mapping and meaningful data processing.
While AUVs have this technology built in, planblue developed its own in-house navigation system for the diver-operated DiveRay.
This technology ensures precise positioning of the imagery on the seabed, making accurate mapping and year-on-year comparison possible.

Working with hyperspectral data presented an additional challenge.
The hyperspectral camera is a push-broom scanner, which means that movement of the camera through the water introduces distortions in the captured images.
Using data from the navigation and other sensors, planblue was able to adjust for the motion in the data processing.
By combining this with the georeferenced data, planblue can create an overlay of hyperspectral data on top of an RGB image and produce advanced maps of the seafloor.
There are however a few more obstacles to overcome to deliver high-quality, accurate and meaningful information.

DiveRay mapping seagrass in Nice, France.
(Image courtesy: planblue GmbH)
Making turbid water crystal clear

As with any form of remote sensing, one of the challenges that planblue needs to address is the correction of distortion of the observations.
Planblue’s DiveRay typically operates about two metres above the seafloor.
To accurately assess the properties of the vegetation or sediment, the observations need to be compensated for the water column between the DiveRay and the seabed.

While the space community has worked on compensation for light travelling through the atmosphere for many decades, this kind of work is still in very early stages underwater.
The survey in Nice in 2022 was the first opportunity for planblue to test new sensors that gather data required to adjust for varying conditions such as depth, weather, turbidity and other environmental properties.
One of the sensors that was introduced measures downwelling irradiance, which makes it possible to determine how the light is diffused by depth, turbidity and other disruptions in the water column.

After Nice, the follow-up campaign in Turkey presented an opportunity to test the effectiveness of the data processing further by comparing measurements from the two campaigns.
Both surveys took place in the Mediterranean Sea with similar ecosystems, observing the same species of seagrass, Posidonia oceanica.
However, the environmental conditions differed.
In Nice, the conditions were consistent, slightly sunny weather and observations at a depth of 5–6 metres.
In Turkey, the water was deeper, at 25–30 metres, as the project measured the edge of the seagrass.
The weather conditions were also variable, with some sunny days but also rain.
The findings of these two campaigns provided valuable input to enhance the data processing pipelines.
Size matters

Another challenge with underwater imaging is scaling.
Objects underwater seem closer than they really are, and how much closer depends on the water conditions.
For this reason, scaling is a fundamental challenge to anyone working with underwater photogrammetry.
Usually, a correction is carried out manually with a variety of visual aids, such as markers and scale bars, and incorporated into the post processing workflow to estimate the scaling introduced by the water.
As planblue’s mission is to automate as much as possible, it developed its own proprietary field of view correction model to manage this.
Combining the geolocation from the navigation solution and distance of the camera to the seafloor, planblue’s technology can calculate the scaling factor of the water.

Orthographic map with overlays.
(Image courtesy: planblue GmbH)
Big picture

Planblue has therefore made some extensive adjustments to its data processing flow to derive georeferenced benthic reflectance.
In the case of hyperspectral images, it is essential to apply corrections to the data.
Instead of creating visual images, the observations from the hyperspectral camera generate numbers that are used to compute indices, which would be meaningless if not calibrated and validated.
The purpose is to obtain objective measurements that are independent of the conditions encountered in the field or caused by the device.
All the metadata measured in the field is time stamped and carefully logged to feed the intermediate processing pipelines that will generate the maps and overlays.

Although a lot of this is now integrated into the automated workflow, full automation of the data analysis remains a work in progress – fine tuning and optimizing the process.
As more of these technical challenges are solved in the data processing pipelines, it speeds up how quickly final data products can be delivered to customers.
This reduction in time-to-data conversion can support more data-driven decision-making for sustainable marine management.
To scale up the reach of the data products, planblue is expanding its operational capacity by integrating its technology as a sensor package into existing underwater drones.

Adding credibility to the blue carbon market

The comprehensive datasets collected using planblue’s technology can be used to visualize seasonal changes in marine ecosystems.
The hyperspectral overlays on the orthoimagery of the seafloor get to the essence of what planblue’s technology has to offer.
The data collected with the hyperspectral and RGB cameras provides detailed insights, for example into the health, biomass and density of seagrass.
This information can revolutionize marine conservation, preservation and restoration.
Knowing not just whether seagrass is present, but also the state it is in, can ensure that policymakers focus on the areas where most impact can be made.
After all, unhealthy seagrass meadows can become net emitters of CO₂, while healthy seagrass sequesters carbon up to 30 times faster than a rainforest.
This thorough assessment of seagrass meadows can take blue carbon projects to the next level and provide the credibility needed to attract investors and accelerate the market.

Planblue’s underwater geospatial technology is driving a transformation in the blue carbon industry, speeding up the protection of vital marine ecosystems with almost instant, credible and accurate data.
The seafloor plays a critical role in regulating the climate, absorbing carbon dioxide and supporting biodiversity.
However, it remains an undervalued and underfinanced carbon sink, lacking detailed information to drive meaningful conservation efforts.

In the recent surveys in France and Turkey, planblue tested and improved its innovative seafloor mapping solution.
Equipped with hyperspectral and RGB imaging capabilities, the company has successfully created objective ground truth data by overcoming challenges with water column distortions and georeferencing.
The comprehensive datasets generated during these campaigns offer detailed insight into seagrass health, biomass, density and carbon sequestration potential.
With reliable data, investors and policymakers can focus their efforts where they can make the most significant impact, both economically and ecologically.

Planblue’s team in action testing the technology.
(Image courtesy: planblue GmbH)

Links :

Tuesday, December 5, 2023

Why does Singapore want to build a 'Long Island'?

Long Island's 800ha of reclaimed land off East Coast could be split into three segments catering to commercial and residential use; recreational activities; and Changi's hub ambitions, according to an expert.
(Graphic: CNA/Rafa Estrada)
From CNA by Matthew Mahan
Experts say the "audacious" plan could meet the country's long-term needs up to 50 years down the line.

Singapore announced on Tuesday (Nov 28) potential plans for a project on its east coast which would reclaim around 800ha of land - the size of over 1,000 football fields.

Technical studies into this "Long Island" will start from 2024 and be carried out over the next few years.
What does it involve?

Twice the size of the downtown Marina Bay area, Long Island could take the form of tracts of land a distance away from the East Coast shoreline, but extending from Marina East to Tanah Merah.

This would create an enclosed waterbody - eventually, a freshwater reservoir - in front of East Coast Park.
Localization with the GeoGarage platform (MPA ENC chart)

Long Island would add around 20km of new coastal and reservoir parks.

It was first mooted under the 1991 Concept Plan, Singapore's second strategic land use and transportation plan.

Prime Minister Lee Hsien Loong mentioned Long Island during his National Day Rally in 2019, and it was showcased at an exhibition by the Urban Redevelopment Authority (URA) last year.

URA said it will seek public feedback and ideas on the plans, including potential names, as Long Island is currently a working title for the project.
Why is it needed?

Coastal protection measures are at the heart of the Long Island plan.

Studies have projected a rise in mean sea level of up to 1m by 2100. Combined with possible high tides and storm surges, sea levels could rise by 4m to 5m, threatening low-lying Singapore's shorelines.

Since 2021, Singapore has studied different parts of its coastline and in September it launched a research centre for coastal protection and flood management.

Around one-third of Singapore - including East Coast Park - is less than 5m above mean sea level. And the effects of high sea levels at the park - Singapore's largest, with a span of about 13km - are already being felt. In 2018 and in January this year, swathes of the park were flooded due to rain and high tide.

Solutions such as a 3m-high sea wall along the entire waterfront of East Coast Park are not ideal: This would limit access to the beach and sacrifice a substantial portion of the park.

The authorities thus settled on Long Island as a more optimal solution.
Hasn't Singapore reclaimed land before?

Yes. The country is no stranger to creating new land from the seas - in particular along its eastern coast.

For instance, the East Coast Reclamation Scheme was launched in 1966 and carried out over seven phases, at a total cost of S$613 million. It reclaimed a total of 1,525 ha of land.

Material for the reclamation came from hills in Bedok and Tampines, and sand was also sourced from overseas.

The reclaimed land was used largely for commercial and residential purposes, with Marine Parade the first housing estate to be built entirely on reclaimed land.

East Coast Park and East Coast Parkway were also born from this reclamation.
What could change?

Dr Woo Jun Jie, senior research fellow from the Institute of Policy Studies (IPS), said Long Island would kill two birds with one stone for Singapore's urban planners and policymakers, in terms of tackling rising sea levels and creating more space for recreation and waterfront living.

"The retention and creation of waterfront spaces around East Coast Park is particularly significant, given that waterfront land is very valuable and presents unique lifestyle and recreational opportunities," he told CNA.

Dr Woo said the impact would be more subdued when it comes to population planning, as the residential portion of Long Island would not be large and would only accommodate a relatively small amount of housing.

Property analysts have said that a mix of potentially up to 60,000 private and public properties would likely be built on the site.

Describing the plan as an "audacious" one, Dr Leong Chan-Hoong, head of policy development, evaluation and data Analytics at Verian, noted that successful implementation of Long Island may give insights on how other parts of Singapore could be redeveloped to protect against rising sea levels.

Professor Sing Tien Foo, provost's chair professor in the real estate department at the National University of Singapore's business school, told CNA the land supplied by Long Island could meet Singapore's long-term needs at least in the next 30 to 50 years.

Given that Marina Bay area reclamation works - spanning 360ha - took more than 20 years to complete and several years for the land to settle before the first commercial project was built, Long Island project can be expected to take even longer time, said Prof Sing.

He said Long Island could be divided into three segments.

The first, connecting to Marina East, would be a natural extension to the future Marina downtown Central Business District and will probably be planned for commercial and residential developments.

In the middle, parallel to East Coast Park, the land could be developed into premium water and recreational activities, said Prof Sing.

And the segment connecting to Changi Airport and Terminal 5 could extend the waterfront district and Changi Business Park, supporting Changi's transformation into a hub for logistics and aviation-related industries.
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Monday, December 4, 2023

Learn the ropes on a hands-on sailing voyage around Denmark's South Funen Archipelago

As charming as the scenery is, it’s sailing a traditional boat that’s the main draw in the South Funen Archipelago, letting the vessel chart the course and drifting wherever the winds blow.
Photograph by Richard James Traylor

From NationalGeographic by Angela Locatelli

A hands-on sailing voyage by tall ship around the South Funen Archipelago offers an authentic glimpse of Danish maritime culture old and new, with colourful port towns, lunches of pickled herring sandwiches and sea shanties sung over drinks with new-found friends.

The mainsail knows how to put up a fight.
“Keep pulling!” calls Helene Moodie, the co-captain on deck, as I battle against its weight.
I cling onto the hoisting line tight enough to feel every fibre, and look up, tracing its course along the mast to the sail, 90 metres tall and like a stage curtain waiting to be lifted.
“Keep pul-ling!” she instructs again, bringing my attention back to the task at hand.
I heave with as much force as I can muster, throwing my entire body back.
A last yank, and the show begins.
The sail catches the wind, billowing full like surging swells.
We’re on our way, fast and proud.

 Visualisation of South Funen Archipelago with the GeoGarage platform (DGA nautical raster charts)
I’m spending six days onboard the Aron, a 98ft, two-mast tall ship dating from 1906, sailing with a handful of other guests around Denmark’s South Funen Archipelago.
Located in the Baltic Sea off the mainland’s southeastern coast, it’s a compact group of 55 or so islands, some home to colourful, immaculately preserved port towns, some so diminutive you could walk their length in an hour.
But as charming as the scenery is, it’s sailing a traditional boat that’s the main draw, and we’re letting it chart our course, drifting quite literally wherever the winds take us.

“Promising we’ll go here or there limits the sailing experience,” says Helene, now relaxing against the railing, the white cockle shell on a silver chain around her neck catching the light.
Below her is a flat expanse of steely sea that stretches to the horizon, broken up occasionally by low-rising emerald isles.
Her partner and co-captain, Gorm Bødker, is at the helm, the perfect image of an experienced sailor — gold loop earring, salt-bleached, wind-tousled hair and tanned skin that shifts to red on his nose and cheeks.
“We’ll take it as it comes, and that’s part of the fun,” Helene adds.

Helene Moddie is the co-caption of the Aron, a 98ft, two-mast tall ship dating from 1906.
Photograph by Richard James Traylor

The other part is getting hands-on with it, joining this two-person crew to man the ship, no matter how inexperienced with sailing guests are.
Even for a beginner like me, there’s always a line to coil, a knot to fasten.
While the vessel is now fitted with an engine, the aim is to sail whenever the wind allows it, cruising in the morning and exploring on land in the afternoon.
We set off from Svendborg, the quaint capital of the archipelago and a historic maritime hub, and now on my second day at sea, I’m already starting to learn the ropes: thick halyards lines are for hoisting a sail, slimmer gaskets for stowing it in place.

It might seem like jargon, but it’s this lexicon that sets apart schooners like Aron, built in the local port of Marstal.
They’re vessels with sails set parallel, rather than perpendicular, to the keel, which helps make them fast and agile on water.
Easy to manoeuvre, Marstal schooners from the 18th and early 19th centuries were icons of Danish maritime trade, which remained the main method of transporting goods around the country well into the 20th century.
But by the 1930s, schooners had fallen out of favour, unable to keep up with competition from steam ships and motor highways.
Helene thinks there are just 35 or so left in Denmark today; of these, fewer than 10 offer charter trips, and only three or four are privately owned, the rest belonging to museums and other maritime institutions.

Helene's ship, the Aron, is a schooner, defined by sails set parallel to the keel.
Photograph by Richard James Traylor

That one of them should have ended up in the hands of this couple seems like a happy turn of fate.
An experienced skipper, Helene was raised on her father’s own schooner, crossing the Atlantic for the first time when still a baby; Gorm cut his sailing teeth on one as a teenager bored with school.
The opportunity to buy the Aron came in 2021, after its previous owner, who’d first repurposed it from a freight to charter vessel, died of old age the very day Gorm was set to start working on it as its new captain.
Ever since then, Helene and Gorm have been offering island-hopping trips: there’s space for 12 passengers in five miniature cabins, each with two or three berths.

On board with me as guests are a Danish and an Irish couple.
Later that morning, we all gather on deck to watch a harbour porpoise breach the rippling waves.
We’re sailing at the same speed and direction as the wind, which feels almost like not sailing at all, like floating weightless between sea and sky.
We pass an islet that ends in a sliver, jutting out in front of another island; caught between the two of them, the sea shimmers like an asphalt road on a hot day, making it all seem like a mirage.

In the afternoon we moor at Lyø island, a two-square-mile blot of woodland and fields, where half-timbered houses are fronted by apple trees, garden gnomes and miniature windmills.
It’s late August, and as I cycle with a bike rented from the harbour, swallows call out from nests under thatched straw roofs.
Honesty stalls sell homemade marmalade and vintage-style bric-a-brac; for all other needs, there’s one grocery store, where the 80 or so islanders meet every afternoon to discuss what happened — or didn’t — that day.

The South Funen Archipelago is compact, so the distance between each island is rarely more than 20 or 30 nautical miles.
Photograph by Richard James Traylor

All hands on deck

Two of the passengers, Malaika Spangsege and Ninna Jensen, in their twenties, are spending the week getting real-life work experience aboard the Aron after completing a five-month maritime training course on another tall ship.
They’re helping out above and below decks, clearing lines, preparing meals in the galley and taking care of everything else in between.
Right now, this involves sitting astride the bowsprit, the spar that reaches from the prow out to sea, to tie up the headsails around it, legs dangling high above water.

“I’m fascinated by life at sea,” Malaika says once back on the relative steadiness of the deck.
We’re sailing away from charming Ærøskøbing, a town on Ærø, one of the bigger South Funen islands, where we’ve spent the night.
A local of Svendborg, Malaika talks about growing up in a place where days are still dictated by the ebb and flow of the tides.
Perhaps as a consequence, she’s in no rush to set her future plans in stone: working on ships is an option, she says, and she hopes this week will help her decide.
“When you live in a city where everybody sails, it’s impossible not to consider a career on deck.”

I can see how you’d get used to this, I think, as I lay back in a hammock strung along the deck.
For every cheek huffed red and aching arm muscle, there are just as many laid-back moments like this on board, and conviviality comes easily.
Helene and Gorm’s 12-year-old daughter, Elise, who joins her parents at sea during school holidays, is reading in the folds of the mainsail stowed above me; her seven-year-old brother, Anton, rope-swings back and forth, his happy hoots and cries growing faint to loud to faint again with each swoop.
The rest of the group is flocking around lunch — platters of open smørrebrød sandwiches topped with pickled herring and onion or Danish mayonnaise and beef sausage, paired with shared bottles of anise-spiced schnapps.

This sense of maritime community, of lives roped together by sailing lines, is also evident in Marstal, the biggest town on Ærø and our mooring this afternoon.
Back when the Aron was built here, Marstal was the second-largest shipping hub in Denmark, surpassed only by Copenhagen.
Today, life remains tethered to the tides.
Shipyards are still active along the harbour, nautical buntings are strung across the main street and votive ships (miniature reproductions of wrecked vessels) hang in the church, tributes to lives lost at sea.
The town’s Maritime Museum tells of its past; the local Maritime School prepares for its future.

Traditional buildings in the town of Ærøskøbing are often painted in brightly-hued tones of yellow, white and reds.
Photograph by Richard James Traylor

“I like the mentality here,” says local sailor Soren Svendsen, a friend of Helene’s, from behind a long ginger beard as we walk along the waterfront later that evening.
“I come from a dead fishing town in northern Denmark, but Marstal is still a working port, a true hub for seafarers.” I met him by chance at the harbour, and he’s offered to give me an insider’s look at the town, where he first moved for his maritime studies.
He started his career working on tall ships, and while he’s now employed on one of the ferries that link the archipelago, he hasn’t lost his love of sails: in two days, he’s off to race in Limfjorden Rundt, the Nordics’ largest wooden-ship regatta.
“There are so many people here who share my interests that I can talk to about my trade.”

He’s taking me to meet some of them this evening — the shanty choir of local sailors he’s part of.
The Marstal Småborgerlige Sangforening (Marstal Petty Bourgeoisie Singing Association) has been meeting for more than 30 years in the same wooden hut, the harbourside deckhouse of an old Danish frigate.
As we walk in, Soren points to its sepia-tinged photographs hanging by the entrance, part of a collection of maritime pictures and paraphernalia that covers almost every inch of the walls.
Two hanging wrought-iron lamps cast a dim light in the room, adding to the time-out-of-time feel of the scene.

The only sign we’re still in the 21st century, in fact, is a small fridge stacked full of beers, which members help themselves to upon arrival and crack open with a nail on the low ceiling.
There are over 30 of them in total, but the 17 that show up today are enough to fill all the seats around a long wooden table, scattered with bottles and shot glasses.
Many are in their seventies and, I’m told, have been friends since their teenage years; what all have in common is the water, be they retired skippers or teachers at the Maritime School.

The Marstal Småborgerlige Sangforening (Marstal Petty Bourgeoisie Singing Association) has been meeting for more than 30 years in the same wooden hut.
Photograph by Richard James Traylor

Despite the untidy practice room, this is hardly a ragtag group.
All members sport blue jumpers with a white logo of an accordion-playing sailor.
Should one forget to wear theirs, the price to pay is whatever the bar tab amounts to at the end of the night.
There’s a chairman and a manager, who pulls me in for a hug when I offer a hand.
They sing at local festivals and, over the years, have even recorded three albums.
Chatter and raucous laughter are big hits this evening, but soon they all produce a songbook, ready to go over the rest of the repertoire.

The shantyman, who leads the singing, stands up to intone a line and the chorus answers in unison, the bold keeping the tempo with a shimmy of the shoulders, the self-aware with a tapping of the finger.
They sing about the Second World War and the most beautiful girl in Dublin; they sing in upbeat notes, with longing tones and mournful resonance.
Sometimes they break out in laughter, in hand claps and high-pitched whooping.
But mostly, they look each other in the eyes, hold each other’s gaze, brothers in a town where saltwater runs thicker than blood.

On the right tack

“If you look closely, the islands tell their story,” says Rasmus Elmquist Casper, executive manager of the South Funen Archipelago Geopark, as he traces their outlines on a map spread open on the Aron’s deck.
We’ve spent the morning sailing north from Marstal to Skarø, one of the smallest inhabited South Funen islands, where we’re moored for our last night at sea.
Rasmus has joined me onboard after sailing here, too, coming from Svendborg on his own single-mast wooden boat to tell me about the geopark.
“It’s my job to share the history of this area, what’s special about it.”

Captain Gorm Bødker is at the helm.
Sailing an old vessel like the Aron is one of the best was to explore the South Funun Archipelago and the preserved traditional maritime culture.
Photograph by Richard James Traylor

As he talks, the sky turns a mutinous grey, setting the scene for the tale of natural upheaval to come.
The archipelago, Rasmus explains, was a uniform landmass during the last Ice Age, which ended some 11,700 years ago.
Retreating glaciers shaped the area into hills, which became islands once the ice eventually melted, causing sea levels to rise 400ft and flood the now-submerged coasts.
The resulting “inundated Ice Age landscape” around us, as Rasmus calls it, is one of the largest in the world of its kind.

Covering 1,055sq miles, the South Funen Archipelago Geopark was established in 2018 with the aim of becoming a UNESCO Global Geopark, which Ramsus hopes might happen soon.
And it’s a project that celebrates the area’s culture as much as its geology.
“The changing landscape gave way to a lifestyle focused on sailing, and this heritage is still alive today,” says Rasmus, tilting his head to point to his ship.
“Vessels here practise traditional maritime culture, not for show, but because it’s still a way of living.”

It’s for this reason, he says, that sailing an old vessel like the Aron is the best way to explore.
But over the past 20 years, a network of outdoor activities has been developed on land, too, from the 137-mile Archipelago Trail to mountain-biking routes and horse-riding areas.
Later, I follow a walking path around Skarø, from the harbour to the scattering of houses that form its only village, and then on through its fields.
The salt marshes here, like many areas in the archipelago, are protected breeding sites for wading birds; when the path meets the sea again, a flock of redshanks takes flight from the shallows, lifting high over a carpet of wildflowers.

Traditional houses on Strynø island are built with thatched straw rooves.

Beach roses are some of the wildflowers the birds fly over when departing from the salt marshes on South Funen islands which act as protected breeding sites.
Photograph by Richard James Traylor

The next morning, on our last sail back to Svendborg, I sit next to Gorm at the stern.
Eyes fixed on the horizon, he turns the helm and it screeches, a rusty cry for oil.
“It’s screaming at me,” he sighs, “I’ll have to do something about it.” Ever since becoming the Aron’s captain, he spends all his time ‘doing something about it’; even on his days off, he’s onboard if a storm’s forecast, if the harbour water gets too shallow.
“If I have a weekend, just one, when I don’t come and see it, I worry.” he says.
“This ship’s one big baby that never learned how to behave.”

I look at the length of the Aron from its stern, fancying it more a demanding partner than tantrum-prone child.
And on its last hurrah of this trip, it’s out in its best gown.
We’ve set it in a ‘goosewing’, meaning the mainsail and foresail are stretched taut in opposite directions, ensuring one doesn’t cover the other so we can make the most of today’s wind, blowing from behind.
They look like arms sprawled open wide, giving the ship the air of a performer ready for their final bow.
It’s easy to see why Gorm is so determined to preserve this.
“It’s culture, too,” he says.
“We’re the last boats left doing this as it’s meant to be — as little schooners earning money for little families.”

Later, we bring the mainsail down one last time.
If hoisting it had been a work of force, stowing it in place is one of patience, folding the canvas back and forth on itself as it’s let down along the mast.
I repeat the motions, tucking the sail back, pleating it forward; a moment of distraction and it’ll droop down one side.
I think back on what Gorm said: to care for the ship, like to fold this sail, requires unflinching attention.

“It’s a constant worry, but it’s a good worry,” he says, guessing my thoughts when I return to join him at the stern.
“I take care of it, and it takes care of me.” It’s a nice thought — that for the ship to be here, somebody must have been doing this since 1906, checking on it every day, every weekend.
Gorm pats the helm, not a child or a partner but a friend, and I know the Aron is in safe hands for years to come.

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Sunday, December 3, 2023

Who is polluting the ocean with plastic?

People produce around 350m tonnes of plastic waste per year, a figure projected to almost triple by 2060. The ocean is suffering, as plastic pollution threatens marine life and human coastal communities.
Small island states are often disproportionately affected, because of their dependence on fishing and tourism.
This film looks at what these islands can do about a global problem that must ultimately be fixed by bigger, richer countries.
It explores the potential of a new technology to improve recycling.