Saturday, June 7, 2014

Robby Naish surfing on the Amazon


From GuinnessBook

The famed Pororoca tidal bore on Brazil's Amazon River is no easy beast to tame.
When the tide hits the confluence of the Amazon and the Atlantic Ocean just right, it results in waves up to 4 m (13 ft) high that can travel for hundreds of kilometers.
This tidal bore has earned a reputation as a surfing hotspot, drawing some of the world's best to ride the Pororoca for some length.
But anybody can ride waves downstream.
Robby Naish prefers going against the grain.

"Five hour flight to LA, 11 hour flight to Sao Paolo, 3 hour flight to Sao Luis, then a three hour drive to a river 80 kilometers inland from the Atlantic coast to SUP a Pororoca tidal bore wave!Only one wave per day for three days, but the longest rides I have ever had."

The famed water sports athlete, with the backing of Red Bull, recently broke the record for the widest ride of a river bore on a stand-up paddleboard (SUP).
Cutting across the daunting tide, Naish paddled 450 meters (1,476 ft 4 in) over the Arari Pororoca, crossing from bank to bank.
Naish has enjoyed a long and storied career on the water.
A 24-time world windsurfing champion -- winning his first world title at age 13 in 1976 -- Naish has also branched out to kitesurfing and now SUP since retiring from competition.


Due to its tidal dependency, the bore appeared at a different hour each day, with Naish beginning his daily preparations at 6 a.m. across three days of attempts.
“The main challenge with the width record was trying to get from one side to the other as the bore tide wave shifts, because it is never connected all the way across at once," Naish said afterward.
"You weren’t just standing there riding one peak for ages. You had to look at the contour of the side of the river and figure out what to do to follow the wave."


Naish completed his 450-m crossing in just under 10 minutes.
He caught his record-breaking wave at 8:38 a.m.
Many times an unofficial world record holder for high speeds and other categories in his windsurfing days, this successful attempt marks Naish's first fully authenticated Guinness World Records achievement.


"This was the first time anyone has organized an actual challenge and record that we were trying to achieve," Naish said. "It was neat and exciting, sort of opens the door for opportunities to think about more things that could be attacked from that perspective."
And, if you ask the 51-year-old, he isn't done breaking records yet.
Whether or not they have anything to do with board sports is a different story.
"There are definitely possibilities out there with all the things that I do, so I’m going to have a look," Naish concluded.
"I’m definitely going to pull the Guinness World Records book out again and look at what the options are. Grow a big beard or something."


"A lot of people call me ‘Waterman’," Naish said.
"But I see myself as a 'board' person. It doesn't matter if it's surfing, windsurfing, kitesurfing, stand-up paddle, skate, or snowboard. I love the feeling of gliding, whether on water or some other surface."
Having competed around the globe in his career, Naish received a unique challenge on the Amazon, as the combination of river movements, heat, and the particularities of the massive ecosystem made the attempt a tall task.
The fickleness of the bore itself played a major role, for instance.

Friday, June 6, 2014

Mapping out a vital part of D-Day history

From the June 19, 1944, issue of TIME. (TIME Magazine)

From Wilts&GloustershireStandard by Brendan McFadden

ON June 6, 1944, Operation Neptune marked the beginning of the invasion of German occupied Europe by the Allied Forces under the command of General Dwight D. Eisenhower.

The Second World War invasion on the Normandy coast of France became commonly known as D-Day, and was the largest amphibious assault ever executed, involving five army divisions supported by over 7,000 ships and 11,000 aircraft.

Plans for D-Day were underway months in advance.

It is a little known fact that American regiment, the 654th Engineer Topographic Battalion, which was based in Tetbury (UK), had a key role in the success of the invasion, which was a major turning point of the war.
As part of a top secret project, the Tetbury-based troops devised a 3D map of Omaha Beach which became a vitally important tool used to capture the beach and move inland.

Troops with the 3D map of Omaha beach which they made at the Old Malthouse in Tetbury

Tetbury historian, Merlin Fraser has researched the work of the 300-man regiment, uncovering how they produced eight million ordinance maps, which helped American troops plot their route to Germany following D-Day.

 Omaha beach detailed
(other : Utah beach)

Merlin is documenting his findings in a book called the Americans in Tetbury and together with Tetbury Town Council he has worked to install a plaque in the town to commemorate both the 70th anniversary of D-Day and the GI’s work in the town.
“In the grand scheme of all things historical what happened in the small Cotswold market town of Tetbury during the six months prior to those landings paled into obscurity overshadowed by the true horrors of war and what happened on those beaches that day,” Merlin said.
“The American soldiers stationed here were not front line troops and they were not part of that first day, however the work they did was of vital importance to the preparation, planning and execution of both Operation Neptune and Overlord.
“In a nutshell I guess you could say that these troops were part of the ‘Back Room Boys’ of Military Intelligence.”

 Wilts and Gloucestershire Standard: Soldiers from the battalion assemble maps
in a trailer in Berlin as part of the American’s march to Germany

The plaque, in the north-east corner of the Chipping car park, will look towards the old Malt House, where the 3D model of Omaha was created.
It is being unveiled on Friday, June 6 at 11am by Tetbury mayor Sandra Ball.

Aerial photo shows troops landing on D-Day at Sword Beach, France on June 6, 1944.
(British Ministry of Defense)
The battalion was split into three sections.
Company A, was based in and around the town, including the Old Malt House and was responsible for turning aerial reconnaissance into maps.
Company B was based at nearby Chavenage House and printed the maps.
Headquarters and the battalion’s officers were also based there.

Left : weather maps for 1,2,3 June 1944 at 1300GMT
Right : weather maps for 4 June 1300 GMT and 6 June 0600 GMT
(History of meteorology, James Fleming)


Chris Tubbs Deputy Chief Forecasters at the Met Office UK uses original weather charts for the day of the invasion, Tuesday the 6th of June.
He shows how there were brisk, north westerly winds coming across the country.
However some shelter from the wind and waves was provided in the Channel, enabling the allied, invasion troops to land successfully in Normandy.

In total, 75,215 British and Canadian troops and 57,500 US troops stormed the beaches on D-Day. with 23,400 landing from air by parachute or glider.

Prepared by the Commander Task Force 122, April 21, 1944.
"Map from GSGS 4490 Sheets 79 and 80 and air photo examination. Grid square equals 1 kilometer (1000 meters)."
Original scale 1:7,920.
"TOP SECRET - BIGOT Until Departure for Combat Operations -- Then This Sheet Becomes RESTRICTED".

After the Normandy Beaches success, the 654th Battalion followed the army across Europe, taking their survey, mapping and printing skills with them.

 'Approaches to Arromanches les Bains'.  A chart produced by the UK Hydrographic Department in July 1944 showing the layout of the harbour and soundings collected by HM Motor Launch 1001, the inshore survey vessel assigned to Mulberry B.

A photo mosaic from August 1944 showing an overview of Mulberry B as it was when in service.
(UKHO)

Merlin explained: “Omaha was the kick-off point but the maps were basically used for any theatre as they advanced." They resurveyed the area as they were advancing.”

Links :
  • Gigapan : D-Day map used by the allied forces to plan and execute the D-Day landings.
  • AppStore : D-day Hour by Hour
  • DailyMail : 'Port Winston' Mulberry harbour built off Normandy after D-Day is uncovered on the seabed 69 years later
  • CCOM UNH : High-Resolution Multibeam Sonar as a Tool for Archaeological Investigations: An Example from the D-Day Beaches of Normandy
  • UKHO : The Mulberry Harbours
  • Dassault Systems : D-Day Landings in 3D Virtual Reality

Thursday, June 5, 2014

USGS iCoast – Did the Coast Change?

iCoast: a new application from USGS to monitor coastal changes

From USGS by Ethan Alpern

Hurricane season starts again this June.
Do you know what happens to our coasts after these extreme storms?

The U.S. Geological Survey has launched a new crowdsourcing application called “iCoast – Did the Coast Change?” to show you these coastal changes from extreme storms.
iCoast allows citizen scientists to identify changes to the coast by comparing aerial photographs taken before and after storms.
Crowdsourced data from iCoast will help USGS improve predictive models of coastal change and educate the public about the vulnerability of coastal communities to extreme storms.


Aerial Imagery of the Coast Before and After Storms

Since 1995, the USGS has collected more than 140,000 aerial photographs of the Atlantic and Gulf coasts after 24 hurricanes and other extreme storms.
Just for Hurricane Sandy alone, more than 9,000 aerial photographs were taken a week after the storm.

USGS acquires high-resolution oblique aerial photography after extreme storms and compares them to imagery collected before the storms.
These aerial photographs are taken at a low altitude to capture a small area of the coast.
USGS collects aerial imagery to ground truth and improve the USGS coastal change probability models.

“Computers cannot yet automatically identify damages and geomorphic changes to the coast from the oblique aerial photographs,” said Sophia B. Liu, USGS Mendenhall Postdoc Fellow.
“Human intelligence is still needed to finish the job.”
Without the personnel or capacity to analyze all the photographs taken after every storm, the USGS decided to launch a citizen science project, asking citizens to help identify changes to the coast while also gaining knowledge about coastal hazards.

 USGS determines probabilities of hurricane-induced coastal change for the Atlantic and Gulf coasts of our Nation to better inform evacuation, response, preparedness, and mitigation efforts.

The Power of Citizen Science and Crowdsourcing

Analyzing the aerial photographs to identify storm damage will help coastal scientists refine their predictive models of coastal erosion and damage caused by extreme storms.
Currently, these mathematical models are derived from dune elevation and predicted wave action during storms.
Adding the human observations will allow the scientists to validate the models and to provide better predictions of damage before storms occur.

“After an event like Hurricane Sandy there is always a great interest in our photographs,” said Barbara Poore, USGS Research Geographer.
“The USGS iCoast team hopes that people will learn about coastal change and about their personal vulnerabilities to extreme storms.”

 View of Mantoloking, NJ before and after hurricane Sandy
NOAA, Google Maps/Denny Gainer, USA TODAY

Integrating Citizen Science into the Model

Research on storm-induced coastal change hazards provides the data and modeling capabilities to allow the USGS to identify areas of the U.S. coastline that are likely to experience extreme and potentially hazardous erosion during hurricanes or other extreme storms.
To assess coastal vulnerability to extreme storms, the USGS has developed a Storm-Impact Scale to produce Coastal Change Probability estimates.
Hurricane-induced water levels, due to both storm surge and waves, are compared to beach and dune elevations to determine the probabilities of these types of coastal change processes:
  1. Beach Erosion occurs when wave runup is confined to the beach.
  2. Dune Erosion occurs when the base or toe of the dune is eroded by waves and storm surge.
  3. Overwash occurs when sand is transported and deposited landward over the beach and dune by waves and storm surge.
  4. Inundation occurs when the beach and dune are completely and continuously submerged by storm surge and wave runup.
Benefits of the USGS iCoast Project

There are scientific, technological, and societal benefits to the iCoast project.
The crowdsourced data from iCoast will enhance predictive modeling of coastal erosion to better inform emergency managers, planners, and residents of coastal vulnerabilities in their regions.

Citizen science projects like iCoast serve the cause of Open Government and Open Data, by sharing USGS aerial imagery with the public.
iCoast can also be a great tool for marine science educators to create interactive and fun lessons related to coastal hazards.

How to Use iCoast:


Wednesday, June 4, 2014

Absurd creature of the week: the Anglerfish and the absolute worst sex on Earth

A female Melanocetus eustales.
Photo: Theodore W. Pietsch

From Wired by Matt Simon

Teen movies are, at their core, veiled studies in evolutionary biology, with young men and women coming to sexual maturity and either giving into or resisting what is arguably an animal’s sole purpose on this planet — to find a mate.
Some decide to wait until they’re married, others lack the desirable traits to even get that far, and still others succeed and consequently have to put off college for a while.

But if the deep-sea anglerfish happened to have the cognitive and physical capabilities required to produce its own such films, there’d be decidedly fewer plot twists.
Every single movie would go a little something like this: Boy meets girl, boy bites girl, boy’s mouth fuses to girl’s body, boy lives the rest of his life attached to girl sharing her blood and supplying her with sperm.
Ah, a tale as old as time.

3D scans reveal deep-sea anglerfish's huge final meal 
A rare hairy anglerfish that entered the Museum's collections 13 years ago had perplexed researchers with its massive stomach.
However, the specimen was so rare they didn't want to cut it open to identify its last meal.
Now, using micro-CT scanners, the Museum's imaging experts have finally been able to solve the mystery.

The over 300 extremely varied species of anglerfishes inhabit everything from shallow to super-deep waters, and are so named because they are fish that fish for fish using lures, which are actually highly modified spines of dorsal fins that have migrated to their snouts.
But among the 160 deep-sea species, only some 25 engage in the aforementioned biting-fusing-mating, what is known as sexual parasitism.
In this group, the diminutive male looks like an entirely different species, lacking the female’s enormous jaws and characteristic lure.

This is because he doesn’t need to hunt.
He only exists to attach to a female, and according to evolutionary biologist Theodore W. Pietsch of the University of Washington, mates are so scarce down here that it might be that only 1 percent of males ever find a female.
The rest starve to death as virgins — unfortunate guys in a sea that doesn’t have plenty of other fish.

A female Haplophryne mollis.
Photo: David Shale

But it isn’t for lack of trying.
The male has the biggest nostrils in proportion to its head of any animal on Earth, according to Pietsch.
These sniffers are paired with extremely well-developed eyes, “so we think that it’s kind of a dual approach,” he said.
“The female emits a species-specific smell, a pheromone, and the male searches out based on that, and then when the male gets close enough, the eyes can be used to distinguish the female of the correct species.”
And with two dozen other species of anglerfishes that engage in this manner of reproduction, the male had better be damn sure he chooses the right one.
Luckily, the female puts on the red blue light — in the form of glowing bacteria living in her lure. Incredibly, some 90 percent of species in the deep utilize such bioluminescence.
“The bait out there is not only an organ of luminescence, but structurally it’s species-specific,” said Pietsch.
“Every species of these 160 forms within this group, they have a pattern of filaments, and pigment patterns, and probably also light flash patterns, like fireflies. And they separate themselves out that way so that males can find females,” distinguishing “the tiny little differences between the structure of the bait.”

 A female Himantolophus appelii.
Photo: Theodore W. Pietsch

Once the male closes in, he bites onto the female, usually her belly, and their tissues fuse together to permanently join the pair in incredibly unholy matrimony.
The male’s eyes and fins atrophy away, and here he will live out the rest of his life nourished by her blood, still breathing with his own gills and, importantly, still producing sperm.
“This establishes a hormonal connection,” said Pietsch, “so that probably the maturation of eggs and sperm is synchronized by the sharing of hormones.
And once the eggs are mature and the male is ready, she extrudes the eggs” in a kind of gelatinous sheath that can be 30 feet long.
This acts like a sponge, readily absorbing the water that the male has released his sperm into.
Keep in mind that this is happening several miles down, where there is little plankton for juvenile fish to eat.
So the whole gelatinous mess is buoyant, slowly making its way to the surface, where the larvae hatch and feed, ideally growing big and then migrating down to the depths.
The females of these species can live 30 years, according to Pietsch, and over that time might collect several males, who provide sperm season after season after season (there is no “not now, honey, I have a headache” with anglerfishes).
But other than the security of maintaining a constant source of sperm, why evolve such a complex ritual of reproduction in the first place?
“The idea is basically that it’s a deep-sea economy measure,” ichthyologist James Maclaine of London’s Natural History Museum wrote in an email to WIRED.
“An anglerfish couple requires about half of the amount of food they would if the male was the same size as the female (and presumably living an unattached life).
He is stripped down to the absolute bare essentials, she has to remain big due to the relative cost of making large eggs as opposed to tiny sperm.”
Where such a size difference between sexes, known as sexual dimorphism, gets really interesting is its manifestation in the world at large.
The famed evolutionary biologist Stephen Jay Gould wrote about this in his essay “Big Fish, Little Fish” — which stars the anglerfishes, of course — arguing that in the majority of animal species, females are larger than males, because the latter often never need to fight for the former.

 A female Lasiognathus amphirhamphus.
Photo: Theodore W. Pietsch

For creatures like lions and gorillas and even humans, the largest male has an obvious advantage in the quest to mate (and therefore better odds at passing along his genes).
But with deep-sea anglerfishes, the male not only doesn’t fight other males, he’s lucky to even find a female in the first place.
Hence their puny size and remarkable mode of reproduction.
He’s really missing out, though, on all those great fishing trips that the females take, with their gaping maws, needle-like teeth, and highly expandable stomachs, which are yet more remarkable adaptations to the abyss.
“At the depths at which many deep-sea anglers live … food rapidly becomes more scarce the deeper you go,” said Maclaine.
“Therefore, a lot of fish have evolved various means of being able to tackle large prey items. When you’ve managed to catch your first meal in weeks, you don’t want to have to let it go because it’s too big. Therefore big mouths, fearsome teeth, and elasticated stomachs have all become common features.”
In fact, many female deep-sea anglerfishes can swallow prey twice their size, as Maclaine shows in the video above.
They are, after all, sometimes eating for several freeloading males.
High school boys.
They’re all the same.

Tuesday, June 3, 2014

MH370 spur to 'better ocean mapping'


Seafloor topography in the Malaysia Airlines flight MH370 search area.
Dashed lines approximate the search zone for sonar pings emitted by the flight data recorder and cockpit voice recorder popularly called black boxes.
The first sonar contact (black circle) was reportedly made by a Chinese vessel on the east flank of Batavia Plateau (B), where the shallowest point in the area (S) is at an estimated depth of 1637 meters.
The next reported sonar contact (red circle) was made by an Australian vessel on the north flank of Zenith Plateau (Z).
The deepest point in the area (D) lies in the Wallaby- Zenith Fracture Zone at an estimated depth of 7883 meters.
The Wallaby Plateau (W) lies to the east of the Zenith Plateau.
The shallowest point in the entire area shown here is on Broken Ridge (BR).
Deep Sea Drilling Project (DSDP) site 256 is marked by a gray dot.
The inset in the top left shows the area’s location to the west of Australia. 
Seafloor
depths are from the General Bathymetric Chart of the Oceans [2010].

From BBC by Jonathan Amos

Scientists have welcomed the decision to make all ocean depth data (bathymetry) gathered in the search for missing Malaysia Airlines flight MH370 publicly available.
A detailed survey of 60,000 sq km of seabed is to be undertaken to help refine the hunt for the lost jet.
The depth and shape of Earth's ocean floor is very poorly known.
Leading researchers say the MH370 example should be a spur to gather much better data elsewhere in the world.
The search has been hampered by the lack of a high-resolution view of the bed topography west of Australia.
This was apparent on the very first dive made by an autonomous sub investigating possible sonar detections of the aircraft's cockpit voice and flight data recorders.
It was forced to cut short the mission because it encountered depths that exceeded its operating limit of 4,500m. There are places thought to exceed 7,800m.

Australian Transportation Safety Board (ATSB) officials said this week that an area in the southern Indian Ocean the size of Tasmania would now be subject to a full survey using multibeam echo sounders (MBES).
A Chinese navy vessel, Zhu Kezhen, has already started on the project.
It will be joined by a commercial ship in June, with the work likely to take three months.


Drs Walter Smith and Karen Marks have assessed the paucity of bathymetric data in the region in an article for EOS Transactions, the weekly magazine of the American Geophysical Union.
The pair work for the US National Oceanic and Atmospheric Administration (Noaa).
They say only two publically accessible data-acquisition sorties have been conducted close to where search vessels made possible black box detections, and "both expeditions occurred prior to the use of modern multibeam echo sounders, so depth measurements were collected by single, wide-beam echo sounders that recorded on analogue paper scrolls, the digitizing of which is often in error by hundreds of metres".

Topex

Modern MBES uses GPS to precisely tie measurements to a particular location.
The equipment can not only sense depth very accurately (to an error typically of 2%), but can also return information on seafloor hardness - something that would be important in looking for wreckage in soft sediment.
Just 5% of a vast region, 2,000km by 1,400km, which includes the search locality, has any sort of direct depth measurement, Smith and Marks say.
The rest - 95% - is covered by maps that are an interpolation of satellite data.
These have a resolution no better than 20km. Maps of the arid surface of Mars are considerably better.

"The state of knowledge of the seafloor in the MH370 search area, although poor, is typical of that in most of Earth's oceans, particularly in the Southern Hemisphere," the pair write.
"In many remote ocean basins the majority of available data are celestially navigated analogue measurements because systematic exploration of the oceans seems to have ceased in the early 1970s, leaving the ocean floors about as sparsely covered as the interstate highway system covers the United States.
"When these sparse soundings are interpolated by satellite altimetry, the resulting knowledge of seafloor topography is 15 times worse in the horizontal and 250 times worse in the vertical than our knowledge of Martian topography."

 West Australia bathymetry with AHS nautical chart (Marine GeoGarage)

Smith and Marks hope that the detailed survey work now being conducted in the search for MH370 will be a catalyst to gather better data in other parts of the globe.
High-resolution bathymetry has myriad uses.
"Better knowledge of the ocean floor means better knowledge of fish habitats. This is important for marine conservation, and could help us find biological resources including new medicines," Dr Smith told BBC News.
"It means also a better ability to assess the mineral resource potential of the seabed. And it means better knowledge of the obstacles to flow that cause turbulence and mixing in the oceans.
"We need this mixing and circulation information to make good models of future climate. All of these things depend on knowing the topography of the sea floor."

The Australian Joint Agency Coordination Centre, which disseminates all information on the hunt for MH370, confirmed that the MBES survey data would be publicly available.
"The bathymetry data gathered in the course of the search for MH370 will become the property of the Australian Government. Recognising the importance of that data, it will be made available to the public via both Australian and international databases," the JACC told the BBC.

  • Most ocean maps are derived from satellite altimeter measurements
  • Satellites infer ocean-floor features from the shape of the sea surface
  • They detect surface height anomalies driven by variations in local gravity
  • The gravity from the extra mass of mountains makes the water pile up
  • In lower-mass regions, such as over troughs, the sea-surface will dip
  • Limited high-resolution ship data has calibrated the satellites' maps
On Tuesday, all the raw satellite data from the London telecommunications company Inmarsat was also put in the public domain.
It was this information that led investigators to look for wreckage in the southern Indian Ocean.

Links :

Monday, June 2, 2014

Changes on the Cape Cod coastline


NASA, acquired July 30, 2013

download Google Earth file (KML)  acquired 1984-2013

 NOAA nautical chart upon Google imagery on the Marine GeoGarage

From NASA

Beaches are dynamic, living landscapes, and the prime example of beach evolution is the coastal barrier.
These strips of land are usually long and narrow, and run parallel to the mainland.
Sometimes they are islands and other times they are connected to land at one end, a feature dubbed a “spit.”
Scientists estimate that there are more than 2,100 barriers fronting nearly 10 percent of the world’s continental shorelines.
In the United States, barrier spits and beaches line up along nearly a quarter of the coast.

These sandy barriers are constantly raised up, shifted, and torn down by the natural ebb and flow of waves, currents, winds, and tides.
Hooks form, inlets open and close, and beaches slowly march across their back bays and lagoons toward the mainland.
This process allows them to naturally move ever upwards as sea levels rise.

On the southeastern elbow of Cape Cod, where the New England coast reaches out into the cold and choppy North Atlantic, this natural progression has been taking place in full view of satellites for more than 30 years.
The images above were acquired by the Operational Land Imager on Landsat 8 (top) and the Thematic Mapper on Landsat 5 (bottom).
They show the shape of the coast off of Chatham, Massachusetts, on June 12, 1984, and July 30, 2013.

 Turn on the image comparison tool for an easier view of the changes (1984-2013)
Visit our longer World of Change time series to see the years in between.

The changes to the Nauset-Monomoy barrier system in this part of Cape Cod are sometimes subtle and sometimes dramatic.
In 1984, an unbroken barrier spit shielded the Atlantic-facing coast of Chatham and its harbor.
South of the mainland, North and South Monomoy Islands stood apart from each other and from the coast.
Over the span of 30 years, three major breaches opened in the system and the barrier islands connected to the coastline and to each other.

According to Graham Giese, a coastal geologist at the Provincetown Center for Coastal Studies, the patterns of barrier and inlet evolution in this area have been going on for at least the past three hundred years, and perhaps longer.
The landmass was laid down at the end of the last Ice Age as the Laurentide ice sheet retreated and rivers and streams of melt water dropped sediment and carved the landscape.
As sea level rose over the past 10,000 years, the ocean ate at the glacial deposits that lay as far as four miles offshore of the present coast.
Sea cliffs—some towering over 100 feet high—were created by wave action, while strong winds produced great dunes.
These features are protected today in the Cape Cod National Seashore.

Giese and other researchers have identified a recent cycle of beach development and migration around Chatham that seems to repeat roughly every 150 years.
Depending on your location along the coast and your timing, the movement of sand around you may be driven by ocean waves or by tides.
Waves usually dominate, promoting longshore transport.
High-energy open-ocean waves from the Atlantic crash into the Nauset-Monomoy barrier system at various angles, scouring the sandy glacial leftovers and creating currents that run parallel to the shore. Erosion along the Nauset-Monomoy barrier system can move the beach anywhere from 1 to 6 meters a year (3 to 20 feet).
Sea level rise—a least one foot in the past century—is also slowly taking away the beachfront.

“Many people view coastal erosion as a problem that needs to be addressed and, if possible, prevented,” wrote coastal geologist Robert Oldale of the U.S. Geological Survey.
“However, storm and wave erosion along the shore of Cape Cod has been going on for thousands of years and will likely continue for thousands of years more. It is a natural process that allows the Cape to adjust to rising sea level. Erosion is only a peril to property. If we build on the shore, we must accept the fact that sooner or later coastal erosion will take the property away.”

Links :

Sunday, June 1, 2014

Deep Water



Videos from Bernard Moitessier's journey around the world single handed in 1968,
Footage from the movie "Deep Water" about Donald Crowhurst's suicide at sea.

Links :
  • GeoGarage blog : Deep water : an unforgettable journey into one man's heart of darkness