Saturday, January 2, 2021

Oceans and human health: a research agenda

What does ‘Oceans and Human Health’ mean and why should we care about it?
This film, created by Seascape Belgium, in the framework of the Seas, Oceans and Public Health in Europe (SOPHIE) project, answers these questions.
The film stresses the need for more research in the area of Oceans and Human Health so that we can better understand the interactions that we have with our coasts, seas and oceans, and how these interactions impact our health and the health of the marine environment.
It calls on a growing community of diverse stakeholders to come together to advance Oceans and Human Health in Europe.
The European Commission funded the Seas, Oceans and Public Health in Europe (SOPHIE) project, a coordination and support action to develop a research roadmap to establish Oceans and Human Health in Europe.
SOPHIE brought marine and environmental scientists together with medical and social scientists, public health and other experts to tackle these complicated issues in a unique forum.
SOPHIE is funded by the European Union’s Horizon 2020 research and innovation programme, grant agreement No 774567.

Friday, January 1, 2021

New Year 2021

The rough seas of 2020 made us better sailors.
Now we can use any wind to sail in any direction.
We wish you all fair winds and let your dreams set sail in year 2021.
 

No better way to start the year than with seconds of pure beauty.
Enjoy!

Thursday, December 31, 2020

Information on ENC generalization, over-scaling and safety checking functions in ECDIS

Rasterized ENC display with the GeoGarage online platform :
Similary with RNC raster charts, a lot easier to see if you’re leaving the intended scale 
(Dubrovnik HHI Croatia)

From IHO

Executive summary

This information paper focuses on the importance of understanding ENC compilation scale and the safety implications of using ENC data beyond its intended usage, during both the Electronic Chart Display and Information Systems (ECDIS) route planning and checking and route monitoring phases of navigation.

The paper provides ECDIS users with information regarding the process Hydrographic Offices employ to transform the physical world into a 2D Electronic Navigational Chart (ENC) that can be used in an ECDIS.

Within the paper the following topics are covered:
  • Cartographic generalization practices
  • ENC Compilation Scale
  • ECDIS safety checking functions
  • ENC over-scaling
  • Conclusions and recommendations

note : while this article applies to ENCs and ECDIS, it is also appropriate for recreational users with ECS or mobile apps.

Cartographic generalization practices

For centuries marine cartographers have been using generalization techniques to transform our view of the world from a true three-dimensional reality to a scaled, two-dimensional abstract view.

Many aspects to generalization are used by Hydrographic Offices when creating navigational products: classification, simplification, exaggeration, and symbolization.  

Classification: Groups features into classes having identical or similar attributes.
Organizing features into fewer classes helps to simplify and clarify the message of the navigational chart.

Simplification: Features are simplified by either smoothing or compacting. Smoothing is generally used for linear features such as depth contours and coastlines where each curve cannot be depicted because of scale or because the detail would clutter the chart.

IHO Chart Specification S-4 states ‘Contours should be smoothed only where it is necessary to remove intricacies which would confuse mariners.
Where necessary, smoothing will include deeper water within shoaler contours (that is: it must be shoal-biased), but an attempt to retain a reasonable representation of the seabed should be made’.

In compacting, if there are many features in a small area, such as isolated rocks which will just be dots at chart scale; those features may be grouped (compacted) within a single obstruction area.

Exaggeration: Due to scale, certain features must be shown larger than their actual relative size. Dangerous features such as rocks, wrecks and obstructions would at certain scales be unreadable if shown at their correct size, so they are exaggerated enough to be recognized and to show their relationship to other similar features.

Symbolization: Symbols are used on charts to inform the Mariner what features are.
Nautical chart symbols use shape and colour to help the Mariner quickly understand the importance of certain features.
For example, the colour magenta is generally reserved for drawing attention to symbols for features which have a significance extending beyond their immediate location; or are not themselves a physical feature (such as administrative and restricted areas; or routeing measures).

Globally accepted cartographic practices include the use of point symbols to represent real- world area features when the scale of the product is reduced but the importance of the feature is such that the cartographer wants to retain that information.

ENC Compilation Scale

The viewing scale of a paper chart is determined and fixed by the cartographer at the chart compilation stage, so symbols are typically larger than the extent of the real-world feature they represent and do not change.
The situation is different when ENCs are used in ECDIS as the Mariner can zoom in and out beyond the ENC compilation scale.
Zooming in to a larger scale introduces the risk that any positional errors that may exist in the ENC data are magnified to a point where the data becomes unsafe to use – and this fact will not be immediately apparent as the ECDIS will continue to display the text and symbols at a fixed size.

ENC producers use a variety of methods to define the compilation scale of their ENC data, but for safety reasons these will always take into account the scale at which the source information was captured.

To ensure consistency, and thus contribute to improved display, most ENCs are assigned to one of the IHO’s recommended standard compilation scales.
These are defined within the IHO’s S-65 publication, together with an example of the navigational purpose to which each ENC scale may be assigned.

The various compilation scales define the level of detail that can be included, and how that detail is depicted.
While a feature may be depicted as an area or line feature at a large compilation scale, it may be depicted as a point feature at a smaller scale.
Some object classes within an ENC, such as wrecks, rocks and obstructions including reefs, may therefore be defined by the cartographer as points, lines or areas depending on the compilation scale of the ENC and other factors.
One major factor is whether the symbol for a feature will be larger than its true (real-world) extent, if known, at the chosen compilation scale.

Charted point features only indicate that a certain feature object exists in a given point location.
While a light beacon may be charted as a point feature, a point feature may also define the approximate centre of a feature that actually has an ‘area’, such as a small reef.
This means that, unlike charted area features, the only positional information available for a point feature is its geographical position (a point represented by latitude and longitude coordinates), and not its true extent (such as the distance from the charted point centre of a reef to its edge).
This is particularly important in ECDIS where the Mariner chooses to over-scale the chart display (see Figure 8) 

Figure 1: Comparison of small reef within source data at ENC compilation scale, point symbol depiction on ENC, and source data overlaid on ENC
Images show survey data (left), section of ENC (centre) and ENC superimposed on survey data at compilation scale (right).
Source: Australian Hydrographic Office (AHO) and ATSB (
Australian Transport Safety Bureau)


Figure 2: Comparison of area features and point features at different scales
These images show the same ENC displayed at two differing scales.
The two images demonstrate a key difference between point and area features – area features change size in proportion to the ENC display scale, however the point features remain the same size regardless of display scale.
Source: Electrotech, annotations by the AHO.


ECDIS safety checking function

Since July 2018 all SOLAS vessels of 500GT and upwards are required to be using ENCs created by Hydrographic Offices in type-approved ECDIS equipment.
The use of ENCs within ECDIS provides a wide range of advantages; it simplifies voyage planning, allowing easy modification of routes and offers many safety benefits.
Routes can be checked for potential dangers based on the safety parameters input by the Mariner.
The safety contour defines the safe water the vessel can navigate in based on the depth areas and contours included in the ENC; and the safety depth defines isolated dangers that are located in otherwise “safe” water.
During route monitoring it is also possible for the ECDIS to be configured to alarm and indicate on features set by the Mariner, alerting navigators to impending dangerous situations.

IMO Resolution A.893(21) adopted on 25 November 1999 Guidelines for Voyage Planning states that;
‘(2.1) All information relevant to the contemplated voyage or passage should be considered.
The following items should be taken into account in voyage and passage planning: appropriate scale, accurate and up-to-date charts to be used for the intended voyage or passage, as well as any relevant permanent or temporary notices to mariners and existing radio navigational warnings.’
This clause requires vessels to carry all appropriate scale ENCs for their intended voyage, thus minimizing any effects of generalization and ensuring the ECDIS can alert the Mariner to dangers by using the largest scale data available.

IMO Performance Standard for ECDIS (11.4.6) requires;
‘An indication should be given to the mariner if, continuing on its present course and speed, over a specified time or distance set by the mariner, own ship will pass closer than a user-specified distance from a danger (e.g. obstruction, wreck, rock) that is shallower than the mariner’s safety contour or an aid to navigation.’
The route checking functions built into ECDIS to check and monitor a route for dangers is a fundamental safety benefit for Mariners.
Where passage planning is conducted on ECDIS, use of the route checking function is a key component of the overall process of checking the suitability of a planned route and complements the visual check of that route.

The route checking function is dependent upon a number of parameters set by the Mariner as part of setting up the ship’s ECDIS for the voyage.
These parameters include a vertical accuracy component, resulting in a safety depth setting; and a horizontal accuracy component, which includes both an allowance for the accuracy of the ship’s navigation system and a minimum permissible planned distance from dangers.
These settings may be changed for different voyages, and even different phases of a voyage, based on the bathymetric data quality information included in the ENC (such as the Category of Zone of Confidence in Data (CATZOC) attribute on the mandatory Quality of Data (M_QUAL) feature). The settings combine to create a route safety region around a vessel’s planned track. 

Figure 3: The component parts of determining an appropriate route safety region around a vessel’s planned track
Figure 3 shows the minimum considerations when determining what allowance should be made for charted dangers on or near a planned route.
These include allowances for the accuracy of the ship’s positioning system, and for the accuracy of the chart.
The dashed lines indicate the possible worst- case scenario for the Mariner.
Source: AHO.


The ECDIS safety checking function verifies the user-defined safety corridor against the entire chart database in the ECDIS for dangers, not just against the extent of visual point symbols displayed on screen.
The ECDIS will graphically identify points along the proposed route that are a danger to the vessel and return a textual list of the same hazards.

ECDIS safety check only verifies data along the user-defined corridor; the width of the corridor is set by the Cross Track Distance (XTD).
The safety check will be performed against the largest scale information within the ECDIS system irrespective of the ECDIS display scale.
Point features will only be identified as hazards if they fall within the safety zone being checked regardless of the size of the symbol displayed on screen and regardless of the actual extent of the physical feature it represents.
Due to the compilation scale of the ENC there could be occasions where the charted point feature may not represent the full extent of the real-world feature.
The Mariner must therefore ensure his safety corridor XTD is sufficiently wide enough to identify all navigational dangers along the intended route.
Mariners are also required to conduct a thorough visual check of the intended route to complement the automated safety check.

The two following fictitious examples show how a hazardous point feature could be missed if the correct ENC scale charts are not loaded in the ECDIS and route XTD is not adequately set.

Example 1

In the first example (Figure 4), the charted position of the ‘isolated danger’ point feature representing the reef lies about 55m to the east of the planned route and falls within the route safety region.
As this point lies within the route safety region set by the Mariner, the ECDIS will detect the reef as a danger close to the planned route and include it in the list of dangers for that leg of the route.

Figure 4: Planned route covers the position of the point symbol
(Scale of Figure is approximately 1:6000; scale of ENC containing the point symbol is 1:90000. )
Figure 4 shows the planned route and the ECDIS route safety region based on a 100m Cross Track Distance (XTD) near the point position used to represent the reef within the ENC.
Note that the charted point position lies within the route safety region and will result in an ECDIS alert.
Source: DigitalGlobe, Esri, modified and annotated by the ATSB and the AHO.


Example 2:

In the second example (Figure 5), the planned route lies 55m further to the west.
The charted position of the point feature now lies outside the ECDIS route safety zone set by the Mariner.
In this case, the ECDIS will not detect the reef as a danger on or close to the planned route. However, the reef still clearly presents a danger to the ship.

In this situation, if the vessel has not taken into account the possibility of isolated reefs within the region, and resultantly extended the XTD to at least account for the horizontal accuracy component of the underlying quality information (CATZOC), there is a possibility the danger could be missed during the visual inspection and the vessel could potentially run aground without the ECDIS indicating the danger on the planned route. 

Figure 5: Planned route misses the position of the point symbol
Figure 5 shows a similar planned route and route safety region, 55m further west, near the same point position used to represent the reef within the ENC.
The charted point position now lies outside the route safety region and therefore no longer results in an ECDIS alert.
However the route still passes over the true reef extent.
Source: DigitalGlobe, Esri, modified and annotated by the ATSB and the AHO.


Given the size of the reef in the examples, it must be stressed that it would typically warrant capture by the cartographer as an area feature within an ENC compiled at the scale of the examples; and only at significantly smaller compilation scales would it be captured as a point feature.

A similar scenario and associated safety implications equally applies to the ECDIS look-ahead function and XTD once the ship is underway and monitoring along the planned route.

ENC over-scaling

A key difference to note between charted area features and point features on an ECDIS display is that area features change size in proportion to the scale at which the ENC is being viewed, whereas point feature size remains constant irrespective of display scale (see Figure 2); in other words they are not enlarged as viewing scale is increased.

Additionally, the size and shape of the point symbol does not necessarily represent the size or shape of the physical, real-world feature it is depicting.

Traditionally, nautical cartographers have sought to ensure that the symbol on the chart is larger than the real-world feature it represents when seen at the chart’s compilation scale.
Navigational purpose is also taken into consideration; a chart that is intended for coastal navigation, where it is not intended that the chart is to be used for close approach to isolated features, may also factor into the decision of the cartographer as to whether to depict a feature as an area or a point symbol on the chart.
This practice remains true in the preparation of ENC, where the compilation scale defines the maximum intended viewing scale for that ENC in ECDIS.

However, when the ENC is viewed at scales progressively larger than the compilation scale, the intended relationship between the point symbol and the area feature it represents is broken; as the ENC is progressively ‘over-scaled’ on screen, the symbol represents a progressively smaller proportion of the real-world feature, such as a reef area, on the ECDIS display.
This can lead to an incorrect assumption by the Mariner that they may go closer to the edge of the point symbol when the display is ‘over-scaled’; this would be a dangerous assumption.

As a point feature, a reef is charted in a specific latitude/longitude position on the ENC, typically representing the centre of the area of the reef.
Visually, this means that the symbol representing the reef will always be centred on this position (see Figure 1); and when viewed at the ENC compilation scale, or smaller, the symbol will typically cover the true extent of that reef.
On the ECDIS display, the symbol always maintains an absolute size of 7mm in diameter regardless of the scale at which the ENC is viewed (see Figure 6).
However, if the display scale has been over-scaled to twice the ENC compilation scale, a considerable extent of the reef (previously covered by the symbol), may now extend well beyond the symbol, without any indication of such in the ECDIS (see Figure 8).
 
Figure 6: Isolated danger (point) symbol in ECDIS
Source: IHO.


The ECDIS has the functionality to allow ENCs to be displayed at scales larger than the original compilation scale.
However, the ability to zoom in beyond the compilation scale (the maximum intended viewing scale) has introduced an inherent risk that is not present in paper charts.
To minimize these risks, ECDIS includes indicators to alert when an ENC is being viewed beyond the maximum intended viewing scale.
  1. Over-scale indication shown within the graphical user interface
  2. Over-scale (jail bar) pattern
Source: AHO.
Figure 7: Over-scale indication and over-scale pattern on ECDIS


 Figure 8: Over-scale indication and over-scale pattern on ECDIS
In the image on the left, shown at maximum intended viewing scale, a Mariner can immediately see that passing close to the charted isolated danger would be unwise.
In contrast, in the image on the right, shown over-scaled, passing the same distance from the same isolated danger appears safe. 
Unfortunately, as the symbol has not been enlarged in proportion to the display scale, it no longer fully covers the reef, resulting in a hazardous navigation situation.
Source: AHO.


It is important to also note that the ECDIS will provide an indication if the ship’s position is covered by an ENC at a larger scale than the current ENC being used in the ECDIS display.

Conclusions and recommendations

With many additional ENC tools capable of planning routes the Mariner must still be aware that only the ECDIS is certified for carrying out route planning and monitoring.
To ensure safety and compliance it is imperative that all the appropriate scale ENCs are used in the ECDIS for adequate route planning and monitoring.
The route must be automatically safety checked and a visual inspection performed at the largest scale possible, based on the available portfolio of ENCs, before the voyage commences.
To ensure all dangers are identified by the ECDIS auto safety check function the Cross Track Distance must be appropriately set, taking into account factors such as the accuracy of the ship’s positioning and navigation system; the bathymetric data quality information included in the ENCs (such as CATZOC); and the intended navigational purpose of the ENCs loaded into the ECDIS.

There is a common misconception by some Mariners that zooming in beyond the compilation scale of the ENC allows for greater accuracy – however, this is not the case. In reality zooming in beyond the intended maximum display scale of ENCs may be misleading and dangerous, particularly for ‘isolated dangers of depth less than the safety depth’.

The risks associated with over-scaling the ENC within ECDIS are two-fold:

Firstly, the symbol selected by the cartographer to represent a real-world feature may no longer fully cover that feature.

Secondly, but most importantly, because the text and point symbols stay the same size within the over-scaled ENC, any sense of appropriate distance from a potential danger is no longer intuitive and can result in a false sense of safety that does not reflect reality.

Mariners are strongly advised not to zoom in ECDIS beyond the compilation scale to a point where the ECDIS over-scale indication or pattern are triggered.

Some ECDIS allow the operator to turn off over-scale warnings.
This is not recommended under normal circumstances.

Familiarization with all the core functions of the ECDIS are mandatory requirements within STCW and are essential for safe navigation.
Mariners must be familiar with the properties of the ECDIS; and develop a sufficient understanding of how and when the ECDIS indicates that ENC data is being displayed at an unsafe scale, so that the display settings can be adjusted accordingly. 

Links :

Embarking on Magellan and Elcano’s first journey around the world

Map of the Magellan route from a Battista Agnese atlas (1544).

From El Pais by Elena Sevillano

Using a thousand images and 73 digital features, Google Arts & Culture has devised a new digital experience allowing users to follow in the footsteps of these two groundbreaking explorers

On December 10, 1520, an expedition led by Portuguese explorer Ferdinand Magellan and Spanish navigator Juan Sebastián Elcano crossed what is now the Straits of Magellan, bringing it to the brink of the unexplored vastness of the Pacific Ocean.
Five centuries later, Google has brought its entire technological arsenal to bear to celebrate the fifth centenary of what was the first journey around the world.
 
 
In collaboration with the Spanish Culture Ministry and the Spanish National Commission of the First Trip Around the World, Google Arts & Culture has launched a digital platform that examines the details of the three-year voyage, which lasted from 1519 to 1522, and its impact on Europe’s understanding of the enormity of the planet, using a thousand images, 73 digital features and the support of 12 cultural institutions.
 
Magellan and Elcano’s route for the first trip around the world.

Dubbed “The First Round-the-World Trip,” the initiative invites online users from all over the world to immerse themselves in the minutiae of the journey and accompany the protagonists on their route with reference to historical documents and maps as well as visiting a replica of the Victoria – the only ship to make it back.
It also introduces us to the communities we would find at the explorers’ various destinations if we were making the same journey today.

“The exhibition is divided into three sections that try to explain not only the naval adventure but also the before and after – its consequences, which are evident today,” says a Google Arts & Culture spokesman. The first section, called Expedition, tells us about the preparations for the trip, giving detailed descriptions of the five ships, their crews, their protagonists and the historical context in which the journey took shape. The Exploration section shows the maps and instruments used by the explorers, and the flora and fauna they encountered along the way. Finally, the Transformation section analyzes the legacy of the voyage, which, in the words of the organizers, left “a spherical world connected by oceans, cultural and social exchanges and trade.”

Seville and Sanlúcar de Barrameda in the 16th century

The illustrator Arturo Redondo has provided two interactive maps that allow users to explore the two points of departure, Seville and Sanlúcar de Barrameda, in 1519.

On August 10, 1519, the expedition led by Portuguese explorer Magellan and Basque explorer Elcano left the port of Seville.
 
Seville in 1519, illustrated by Arturo Redondo.
 
Its goal was to seek a new westward route toward the Moluccas or Spice Islands in Indonesia.
The expedition involved five ships – the Trinidad, the San Antonio, the Victoria, theConcepción and the Santiago – and a collective crew of 245 sailors, including Castilians, Portuguese, Greeks, French, Italians, Belgians, English and Germans.
The only ship to return to Seville in 1522 was the Victoria, captained by Elcano.
It came back with 35 men on board after a 1,084-day voyage covering 46,270 nautical miles – about 85,700 kilometers, which is more than twice the Earth’s circumference.
The ship’s reappearance at its port of departure was empirical proof that the oceans were interconnected and that the Earth was round.
“We have discovered and rounded all the roundness of the world,” Elcano wrote to King Charles V of Spain from Sanlúcar de Barrameda on his return.
 
An engraving by Magellan discovering the strait that will bear his name in Patagonia. 
Credits: Hulton Archive - Getty

A virtual walk through a replica of the Victoria


The replica of the Victoria is 26 meters long and six meters wide. It can be visited digitally, with a 360º view, thanks to Google’s Street View technology (click here to see it).
The tour includes its sails (six, with a total area of 286 square meters), the hold, the deck and main mast and the forecastle.
 
 Track of Magellan travel around the world (Heinrich Scherer) / Getty
 
The route

Users can trace the voyage on a detailed map: the journey along the African coast; the arrival on November 29, 1519, in Brazil with a stopover in Santa Lucía Bay in what is now Río de Janeiro; and the journey through the Tierra del Fuego, which was named after the bonfires lit by the native Indians.
On November 28, 1520, the ships Trinidad, Concepción and Victoria found their way to the South Sea via what is now known as the Straits of Magellan, which are 565 kilometers long.
It took 38 days to cross and took them from the Atlantic to the Pacific.
 
In March 1521, the expedition reached the Philippines, where relations with the indigenous people changed from a peaceful exchange of fruits to a fierce battle.
Magellan was killed on the island of Mactan on April 27th.

After 100 days crossing the biggest ocean on the planet, they arrived at the Mariana Islands east of the Philippines and south of Japan; on April 27, 1521, Magellan died in battle, in Cebu in the Philippines; on November 8, 1521, two years and three months after leaving Spain, the expedition arrived in the Moluccas Islands in Indonesia.
 
An engraving of the Victoria, depicting Ferdinand Magellan, top left, and Juan Sebastian del Cano, top right
Credits: Hulton Archive - Getty
 
In September 1519, Magellan left Spain with a fleet of five ships.
Three years later, only one of them, the Victoria (painted here on a 1590 map), returned to Spain after circumnavigating the world.
 

On January 25, 1522, Elcano set out for home on the last surviving ship from Timor on a direct journey westward across the Indian Ocean.
In the spring of that year, he rounded the Cape of Good Hope. Afterwards, he would reach Cape Verde and the Canary Islands. And, on September 8, he docked in Seville.
 
Facsimile of the map attributed to Jorge Reinel, who joined Magellan in Seville - Credits: Gallica/BNF

Mapping the New World

The Google Arts & Culture collection has managed to reproduce high quality cartographic maps that show the transformation of Europe’s vision of the planet after Elcano and Magellan’s expedition.
For example, Juan Vespucio’s 1526 map already incorporates the Straits of Magellan, although he calls it Sant Anton.
 

Links :

Wednesday, December 30, 2020

The Caspian Sea is set to fall by 9 metres or more this century – an ecocide is imminent

Anton Balazh / shutterstock

From The Conversation by Franck Wesselingh & Matteo Lattuada


Imagine you are on the coast, looking out to sea. In front of you lies 100 metres of barren sand that looks like a beach at low tide with gentle waves beyond. And yet there are no tides.

This is what we found when we visited the small harbour of Liman, on the Caspian Sea coast of Azerbaijan.
The Caspian is actually a lake, the largest in the world, and it is experiencing a devastating decline in its water level that is about to accelerate.
By the end of the century the Caspian Sea will be nine metres to 18 metres lower.
That’s a depth considerably taller than most houses.
 
The Caspian borders five countries and is about the size of Germany or Japan.
Rainer Lesniewski / shutterstock

It means the lake will lose at least 25% of its former size, uncovering 93,000 sq km of dry land. If that new land were a country, it would be the size of Portugal.

As we found in our new research, the crisis may well result in an ecocide as devastating as the one in the Aral Sea, a few hundred kilometres to the east.
The Caspian’s surface is already dropping by 7cm every year, a trend likely to increase.
In five years it might be about 40cm lower than today and in ten years almost one metre lower.
Maritime countries worldwide are coming to terms with one metre or so of sea level rise by the end of the century.
The Caspian Sea faces a drop of that size – except it will happen within a decade.

Climate change is the culprit.
The Caspian Sea waters are isolated, its surface is already around 28 metres below global oceans. Its level is the product of how much water is flowing in from rivers, mostly the mighty Volga to the north, how much it rains, and how much evaporates away.

At the end of the century the Volga and other northern rivers will still be there. However, a projected temperature rise of about 3℃ to 4℃ in the region will drive evaporation through the roof.

Future misery despite past crises

The Caspian Sea has a history of violent rises and falls. In Derbent, on the Caucasus coast of Russia, submerged ancient city walls testify to how low the sea was in medieval times. Around 10,000 years ago the Caspian was about 100 metres lower.
A few thousand years before that it was about 50 metres higher than today and even overspilled into the Black Sea.

Depth map of the Caspian Sea: the areas in red and yellow may disappear entirely. Allahdadi et al (2004)
 
Yet people who lived beside the sea were able to overcome the swings.
No human infrastructure was around to be destroyed and many animal species simply moved up and down with the sea levels, as they had done over the past 2 million years or so.
The fall will affect the Caspian’s unique and already stressed animal and plant life, along with human societies along the coasts.

In some areas the coastline is about to retract hundreds of metres a year or more.
Can you imagine building new piers and harbours that fast?
By the time they are ready, the sea will have moved kilometres or tens of kilometres further away.
Coastal promenades will soon be landlocked.
The beaches of today will be the sand ridges stranded in barren plains of tomorrow.

The drop will also affect lowland rivers and deltas around the Caspian Sea.
Once-fertile plains will become too dry for watermelon and rice farming to continue.
 
Unique Caspian life in peril

The town of Ramsar, on the Iranian coast, gave its name to a global wetland convention.
But as the sea recedes, the town is becoming landlocked and the surrounding wetlands will be gone within decades.
 
 
Officially listed as endangered, Caspian seal numbers have declined more than 90% over the past century.
tristan tan / shutterstock

The shallower “shelves” of the northern and eastern Caspian are major food supplies for fish and birds, yet the entire northern and eastern shelves will transform in dry barren lands.
This will devastate fish species, the Caspian seal and a richness of molluscs and crustaceans species unique to the sea.
These Caspian inhabitants have already suffered badly in the past century from pollution, poaching and invasive species.
About 99% of Caspian seal pups are raised on the winter ice of the north Caspian.
Yet both the winter ice and indeed the whole north Caspian will disappear.

Remaining biodiversity hotspots in depths between 50 metres and 150 metres will be affected as rivers dump nutrients into the deeper central basins combined with rising temperatures.
This will decrease oxygen levels and developing ecological dead zones could affect the remaining refuges of Caspian species.
A genuine ecocide is around the corner.
 
 
The Caspian coastline is already receding. Frank Wesselingh / Google Earth, Author provided

The situation cries for action, but possibilities are limited.
Rising global CO₂ levels, the main driver of climate conditions causing the Caspian crisis, can only be dealt with global agreements.
In Soviet times, large scale water diversions from Siberian rivers were proposed to deal with the shrinking Aral Sea to the east.
But such large works – in the case of the Caspian Sea, a canal from the Black Sea might be considered – come with huge ecological and geopolitical risks.

Yet action is necessary to safeguard the Caspian Sea’s unique plants and animals and the livelihood of the people who live around it.
The stranded small harbour in Liman is further from the sea every year.
If no action is taken, it will be left alone in more than one way.
 
Links :

Tuesday, December 29, 2020

World's largest iceberg continues to break up off the coast of South Georgia


 
28/12/2020 SAR sta image / Copernicus Sentinel-1

 
From LiveScience by Rafi Letzter
 
It has now split into 4 distinct pieces.

The world's (former) largest iceberg continues to break apart into smaller pieces on the doorstep of a major marine wildlife haven and home to millions of macaroni and king penguins in Antarctica.

This comes less than a week after the mammoth iceberg, known as A68a, first split in two, Live Science recently reported
 

Scientists at the U.S. National Ice Center (USNIC) spotted the two newest pieces, A68e and A68f, on Dec. 22 using images from the Sentinel-1A satellite, according to a USNIC statement.
This means that there are now four separate iceberg fragments, including A68d, which will eventually drift away from one another.

A68a became the world's largest iceberg when it split from Antarctica's Larsen C ice shelf in July 2017, Live Science previously reported.
The massive chunk of ice has been drifting northward ever since. As recently as April, it measured 2,000 square miles (5,100 square kilometers), or just over the size of the state of Delaware.

In the spring of 2020, A-68a set its sights on South Georgia Island, a wildlife refuge in the South Atlantic Ocean that's home to millions of penguins, seals and other marine wildlife.
Experts feared that if it were to get stuck on the island's shallow sub-continental shelves, it could majorly interfere with the animals' ability to hunt for food.

"The actual distance [the animals] have to travel to find food (fish and krill) really matters," Geraint Tarling, an ecologist with the British Antarctic Society, said in a statement.
 
A68 position from Sentinel-1 image acquired late on 28th Dec. 
 
Map update, A68x as of 2020-12-26
While A68d remains nearby the position of the last days, A68a, A68e& A68f(broken) continued the journey southwards.
Following the currents, "e" already is taking north direction, so we can expect that "a" and f" will follow.
 
"If they have to do a big detour, it means they're not going to get back to their young in time to prevent them starving to death in the interim."

However, it appears that those underwater shelves are actually what has caused it to start breaking apart.
Before splitting in two, the iceberg began spinning clockwise, suggesting one end had been caught on the shelf.
The force of this snag is believed to be behind that split and the more recent fracturing as well. 

Laura Gerrish, a GIS (geographic information system) mapping specialist at the British Antarctic Survey, estimated the areas of the new fragments, according to her post on Twitter:
A-68a: 1,004 square miles (2,600 square km)
A-68d: 56 square miles (144 square km)
A-68e: 253 square miles (655 square km)
A-68f: 87 square miles (225 square km)

It is now hoped that the biggest pieces will be carried north of the island on a fast-moving current known as the Southern Antarctic Circumpolar Current Front.
 
The newly created A68F iceberg itself spawns multiple smaller icebergs

However, if any of the pieces, or any potential new pieces, were to get caught on the shelves, they could still be big enough to cause disruption to the local wildlife, according to the BBC.

Researchers will now continue to monitor the situation over the holiday season, while the island's inhabitants will hope for a non-white Christmas.

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Monday, December 28, 2020

Point Nemo is the most inaccessible place in the world and these are the theories about what lives there

via The Sun

From The Travel by Ketie Machado

Could it be home to the elusive, mythical creature Cthulhu? Or is it just a remote island, completely devoid of life?

Not many have heard of Point Nemo and no - it's not in reference to the Disney movie that shares the same name.
Located roughly 1,000 miles from any reachable land area, this isolated island is only close to two additional remote locations, the Pitcairn Islands, the Easter Islands, and an Antarctic island located more than 1,000 miles away.
In Latin, 'Nemo' means 'no one' which is a more than adequate way to describe this island - it has never been and will never be home to any inhabitants.

Furthermore, it's said that astronauts have often been closer to this island than any one human.
Since the island sits over 1,000 miles away from any known landmass where humans have been, astronauts orbit the earth within at least 258 miles - meaning that even from space, they're still the closest humans to ever reach this point on the earth.
So, with that being said, why is Point Nemo so important, and what is it used for?
Even more so, if humans don't dwell there, then what actually does?

 
The Discovery Of Point Nemo

The mystery of Point Nemo grows increasingly intriguing, as the man who discovered it had never even stepped foot on the island himself.
A survey engineer by the name of Hrvoje Lukatela made the discovery of the land point in 1992 and was able to efficiently calculate both its distance and pinpoint its coordinates by triangulating other known landmasses.
At that point in time, it was also surmised that no human being had ever crossed over the coordinates used due to the remote area of the island - there would have been no reason to - therefore cementing the idea that this island and its surroundings truly are the most remote places on earth.

To add even more depth to this mystery, it's not like that many things live on or around Point Nemo, either.
What is known about this South Pacific location is that it's also home to extremely strong South Pacific currents called the South Pacific Gyre.
This current continuously pushes things through, including any potential nutrients and food sources that would be needed to actually sustain life on the island or in the water surrounding it.
There are volcanic vents in the seafloor which does lend some activity, but it's likely limited to bacteria and crabs which can withstand both the current and the underwater volcanic activity.

Despite The Lack Of Life, It's Awfully Loud On This Island


Point Nemo has been a point of interest for many and has even gained the attention of some scientists who believe there might be something unique happening around this landmass.
In 1997, only five years after the island was actually mapped, an unusual sound was recorded near the pole.
It was the loudest ever recorded underwater sound, beating out noises from both animals and underwater geological shifts.
The sound was so tremendous, in fact, that it was heard in separate places that were more than 3,000 miles apart.

Although they tried, scientists could think of nothing large enough or loud enough to create such a noise.
The sound was something of a bloop, similar to what would happen if a giant bubble were to explode from the ocean floor.
Between the lack of marine life and the lack of seafloor activity, there was seemingly no explaining where this noise came from.
However, some people had a different theory on the sound, and it involved none other than famed horror fiction author H.P. Lovecraft.
In The Call of Cthulhu, Lovecraft actually gave specific coordinates for the ancient city - R'yleh - where Cthulu supposedly came from.
These coordinates happened to be eerily similar to that of Point Nemo, leading Lovecraft fans to believe that just maybe, the author knew something that the rest of the world didn't.
The novel was written in 1928, which led some fans to believe that Lovecraft was onto something and had predicted the existence of a creature yet to be discovered.

The Truth Behind Point Nemo

While it's highly unlikely that Cthulhu is hiding in the South Pacific, scientists eventually did find a way to explain the unusual 'bloop' that occurred under the ocean's surface.
It was determined to be the sound of a piece of ice breaking off Antarctica, thus creating the aquatic noise that was recorded throughout the entire area.

Mystery fans shouldn't be disappointed, though - Point Nemo also has another, somewhat otherworldly purpose.
It's also known as the 'spaceship graveyard.' When spaceships that have been launched from the earth are due to re-enter the atmosphere, they need to go somewhere since the autonomous vehicles are no longer of use to anyone.
The most logical place experts could think of is a remote location that wouldn't interfere with a place that's inhabited, and that place happens to be Point Nemo.
Therefore, if anyone was able to make it to this island, they would see something quite unique - albeit not so mysterious.

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Sunday, December 27, 2020

Crossing the North Sea wintertime

25th of January 2020 I set out again for another North Sea crossing to get to Shetland and the impressive Up Helly Aa vikingfestival.
With 4 degrees celsius, gale winds on the nose, and 4-6 meter waves it is all set for a real battle agains the elements. Toughest North Sea crossing so far! :)
This is my 4th video I make of crossing the North Sea.
Time has come for broadening my adventures, so next long distance video will be to Greenland, starting July 2020. 
Cant wait to get some new untouched oceans, landscapes and experiences attached to my camera lenses.
Dont miss out!
We are not here to be comfortable and safe, it will bring you nowhere.
We are here to fight to get stronger, and to be ready for the next battle! 
 
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