Sunday, November 28, 2010

Settling on the Coast

Taken in 2007 by Expedition 16 astronauts aboard the International Space Station,
this digital image shows Cape Cod, where the Pilgrims first set foot

(position in the Marine GeoGarage)

From NASA Earth Observation

Cape Cod is a haven for waves of migrants who have washed up on American shores.
The most famous arrived in the early 1600s, and hundreds of thousands now visit every summer. But most of the migrants washed up between
18,000 and 23,000 years ago.

In September 1620, English Separatists, also called the
Pilgrims, left Europe to set up a colony near the mouth of the Hudson River.
On November 20, they sighted land and confirmed it to be Cape Cod.
This arm-shaped peninsula of Massachusetts is shown here in 2007 in a digital photograph from astronauts aboard the
International Space Station.

The Pilgrims initially decided to sail farther south, but quickly became wary of the shallow waters and shoals east and south of Cape Cod and Nantucket—waters full of the sandy, rocky outwash from ancient glaciers.
They sailed around the northeastern tip of the Cape and on November 21, 1620, dropped anchor just off the shores of modern-day Provincetown.
While resting in that harbor, they composed and signed the
Mayflower Compact, an agreement to establish self-government.

In the weeks that followed, the Pilgrims explored the Cape and made their first encounter with the
Wampanoag Indians, native people whose ancestors may have explored and inhabited Cape Cod as early as 11,000 years ago.
Eventually, the Pilgrims made their way to the western shores of Cape Cod Bay, landing near an abandoned Wampanoag settlement known as
Patuxet.

Plymouth Rock—which is likely a creation of oral history and legend, since there is no mention of it in the writings of the original Mayflower voyagers—is a glacial erratic, a large boulder that dropped out of a glacier.

The Cape’s sandy peninsula and a fair bit of southeastern Massachusetts is, in a way, also a migrant.
The area was both built up and scoured by the
Laurentide Ice Sheet, which stretched down past Martha’s Vineyard and Nantucket during Earth’s last major Ice Age.
In their advance and retreat, the glaciers composing the ice sheet scraped rock off of Earth’s surface, eventually depositing it on Cape Cod.
The
U.S. Geological Survey estimates that the deposits are 200 to 600 feet thick across the region.

Though this photo cannot show all the rocks left behind, it does show the dozens of kettle hole ponds.
As the ice sheet retreated, sediments washing out of the glaciers occasionally covered chunks of ice.
Those ice blocks would eventually melt and collapse the sediments, creating the space for the fresh groundwater-fed ponds we see today.

Editor’s Note: On the original Mayflower Compact, the date is listed as November 11.
When Western societies switched from the Julian calendar to the Gregorian calendar, 10 days were added, turning November 11 into November 21.

Links :

Saturday, November 27, 2010

Dark side of the lens : the mystical art of surfing



from Astray Films


Dark Side of the Lens presents the art and inner voice of Irish surf photographer Mickey Smith.
The six minute film lets you experience Smith’s aesthetics translated into beautiful practice.
“I wanna see waveriding documented the way I see it in my head, and the way I feel it in the sea.”

Links :

Friday, November 26, 2010

Canada CHS update in the Marine GeoGarage

1316 : PORT DE QUEBEC

42 charts have been updated for Canada (CHS update published November 12, 2010) :

1230 : PLANS PENINSULE DE LA GASPESIE
1316 : PORT DE QUEBEC
1510A : LAC DES DEUX MONTAGNES
1510B : LAC DES DEUX MONTAGNES
2006 : UPPER GAP TO TELEGRAPH NARROWS
2028A : LAKE SIMCOE
2028B : LAKE COUCHICHING - LAKE SIMCOE TO COUCHICHING LOCK
2028C : COOK'S BAY AND HOLLAND RIVER
2064 : KINGSTON TO FALSE DUCKS ISLANDS
2069 : PICTON TO PRESQU'ILE BAY
2123 : PELEE PASSAGE TO LA DETROIT RIVER
3459 : APPROACHES TO NANOOSE HARBOUR
3535 : PLANS MALASPINA STRAIT - PENDER HARBOUR
3538 : DESOLATION SOUND AND SUTIL CHANNEL
3679 : QUATSINO SOUND
3681 : PLANS - QUATSINO SOUND
3891 : SKIDEGATE CHANNEL
3957 : APPROACHES TO PRINCE RUPERT HARBOUR
4141A : SAINT JOHN TO EVANDALE
4141B : SAINT JOHN TO EVANDALE
4170 : GLACE BAY HARBOUR
4244 : WEDGEPORT AND VICINITY
4266 : SYDNEY HARBOUR
4277 : GREAT BRAS D'OR / ST. ANDREWS AND ST. ANNS BAY
4278 : GREAT BRAS D'OR AND ST PATRICKS CHANNEL
4367 : FLINT ISLAND TO CAPE SMOKEY
4381 : MAHONE BAY
4429 : HAVRE SAINT-PIERRE AND APPROACHES
4432 : ARCHIPEL DE MINGAN
4468 : ILE DU PETIT MECATINA TO ILES SAINTE-MARIE
4486 : CHALEUR BAY
4640 : ISLE AUX MORTS AND APPROACHES
4728 : EPINETTE POINT TO TERRINGTON BASIN
4831 : FORTUNE BAY NORTHERN PORTION
4832 : FORTUNE BAY - SOUTHERN PORTION
4851 : TRINITY BAY - SOUTHERN PORTION
4852 : SMITH SOUND AND RANDOM SOUND
4853 : TRINITY BAY - NORTHERN PORTION
4905 : CAPE TORMENTINE TO WEST POINT
4921 : HAVRE DE BEAUBASSIN
4957 : HAVRE-AUBERT
5143 : LAKE MELVILLE
7663 : KUGMALLIT BAY
7750 : APPROACHES TO CAMBRIDGE BAY
7777 : CORONATION GULF WESTERN PORTION
7779 : DEASE STRAIT

So 691 charts (778 including sub-charts) are available in the Canada CHS layer. (see coverage)

Note : don't forget to visit 'Notices to Mariners' published monthly and available from the Canadian Coast Guard both online or through a free hardcopy subscription service.
This essential publication provides the latest information on changes to the aids to navigation system, as well as updates from CHS regarding CHS charts and publications.

Three boys adrift in Pacific for 50 days found alive

More than 1000 km drift

From BBCNews

Three teenage boys have been found alive after being lost in their boat in the Pacific Ocean for 50 days.

The boys, from the
Tokelau Islands, a New Zealand-administered territory in the South Pacific, had been given up for dead after an unsuccessful search.
A tuna fishing boat picked them up near
Fiji and is taking them to hospital for treatment for severe sunburn.

The boys survived on coconuts, water they trapped on a tarpaulin and a seabird they managed to catch.

'Strong mental spirit'

The boys - two aged 15 and one aged 14 - had gone missing from Atafu atoll in a small aluminium boat after an annual sporting event on 5 October.


Atafu island in the Marine GeoGarage

They were presumed to have died after unsuccessful searches by the New Zealand air force.
A memorial service was held for them.

The boys were then spotted north-east of Fiji on Wednesday afternoon by a member of the tuna boat's crew.
"We drew up next to them, and we asked if they needed any help and their reply was a very ecstatic 'yes'," the tuna vessel's first mate, Tai Fredricsen, told the BBC.
"We immediately deployed our rescue craft and got them straight on board and administered basic first aid."

Mr Fredricsen said the boys had a small supply of coconuts on their boat, but that it had ran out after two days.
"They had a period when they were only drinking fresh water, which they were capturing during the night in a tarpaulin," he said.
"They also told me that two weeks prior to us rescuing them, they were able to catch a sea bird which was very lucky for them."
"They did mention that during the last two days they had started drinking salt water, which could have been disastrous for them," he added.

Mr Fredricsen said the boys were in surprisingly good shape considering their ordeal under the blazing tropical sun.
"They've got a lot of gusto, a lot of strong mental spirit. Physically they are very disturbing but mentally they are very strong."

Links :
  • TheGuardian : Teenagers found after 50 days at sea
  • Stuff.co.nz : Miracle survival of three boys
  • DailyMail : Three teenagers, whos survived on raw seagull and fish, found alive after 50 days adrift in tiny dinghy in Pacific Ocean

Thursday, November 25, 2010

Satellites reveal differences in sea level rises

Relative sea-level change rates in millimeters per year (Credit: GRACE)

From InsideScience

Glaciers are retreating and parts of the ice sheets on Greenland and Antarctica are melting into the ocean.
This must result in a rise in sea level, but by how much?
A new measurement of the gravity everywhere around the globe with a pair of orbiting satellites provides the first ever map detailing the rises across different parts of the globe.

According to the new results, the annual world average sea level rise is about 1 millimeter, or about 0.04 of an inch.
In some areas, such as the Pacific Ocean near the equator and the waters offshore from India and north of the Amazon River, the rise is larger.
In some areas, such as the east coast of the United States, the sea level has actually dropped a bit over the past decade.

The surface of the sea is a constantly shifting fabric.
To achieve a truer sense of how much the sea is changing in any one place, scientists measure the strength of gravity in that place.
Measuring gravity over a patch of ocean or dry land provides an estimate of how much mass lies in that region.
The measured mass depends on the presence of such things as mountains, glaciers, mineral deposits, and oceans.

If the gravity measurement for a place is changing, this could mean that the place is losing mass because of a retreating glacier or gaining mass if, as in the ocean surrounding Antarctica, new melt water is streaming in.

The Gravity Recovery and Climate Experiment, or
GRACE for short, consists of a pair of satellites moving in an orbit that takes them over the South and North Poles.
The two craft, nicknamed Tom and Jerry after the television cartoon characters, send constant signals to each other to determine their relative spacing to about 10 microns -- one-tenth the width of a human hair -- over a distance of 130 miles.
If the first craft flies above a slightly more weighty area of the Earths' surface -- like a mountain range -- it will be tugged a bit out of place, an effect picked up by a change in the relative spacing of the craft.

In these way monthly gravity maps of pieces of land or ocean about 180 miles wide can be made with high precision.
The new report for the years of 2003-09 looks at how much mass has been lost from land areas and how much mass has been gained by ocean areas.

One of the authors of the report, Riccardo Riva from the
Delft University of Technology in the Netherlands, said that average annual rise in sea level rise due to meltwater entering the ocean is about 1 millimeter, but that an additional rise will come from that fact that as the average temperature rises so does the ocean temperature, which in turn causes the volume of the ocean to increase.

"The most important result of the new report is the measurement of the sea level changes for specific regions of the Earth that are based on direct and global measurements of mass change," Riva said.

Mark Tamisiea, who works at the
National Oceanography Centre in Southampton, England, and was not involved in the GRACE work, believes the new report represents good research.

"As coastal sea level changes impact society, it is important for us to understand as much about the local differences from the global average as possible," Tamisiea said. "These results are one piece in that puzzle."

"GRACE is definitely the 'real deal' when it comes from measuring climate change from space," said Joshua Willis, an ocean expert at the
Jet Propulsion Laboratory in Pasadena, Calif. "This work by Dr. Riva and company reminds us that the world's oceans don't behave like a giant bathtub. As the ice melts and the water finds its way back to the ocean, the resulting sea level rise won't be the same all over the world."

"These effects are still small in today's rising ocean, but as we look out over the next century, the patterns of sea level change due to melting ice will be magnified many times over as the ice sheets thin and melt," Willis said.

Looking at the actual map of sea level rises presents an ironic twist. Offshore the areas where melting ice is most rapidly falling into the ocean -- such as Greenland and Antarctica -- the sea level appears to be falling.

"The main reason for this is the rebound of the solid Earth," explained Riva.
"Less ice causes the continents go up, and therefore sea level drops. Meltwater distributes around quite quickly, in most cases, so there is no accumulation due to that."

The new GRACE results appear in the journal
Geophysical Research Letters.