Circumnavigate Rangitoto island

A fast blast around Rangitoto Island in Auckland
aboard 'Jaunty' a John Welsford designed Navigator, in wind of up to 35 knots :
about the pleasure of sailing a small boat.

>>> geolocalization with th Marine GeoGarage <<<

 Rangitoto Island, Hauraki Gulf, Auckland, New Zealand

Will jellyfish rule the ocean?

Jellyfish from Anthony Yebra

From LiveScience (by Elizabeth Howell)

In 2000, a bloom of sea tomato jellyfish in Australia was so enormous — it stretched for more than 1,000 miles from north to south — that it was even visible from space.

It was certainly a bloom that Australian jellyfish researcher Lisa-ann Gershwin won't forget.
While most blooms are not quite that big, Gershwin's survey of research on jellyfish from the last few decades indicate that populations are most likely on the rise, and that this boom is taking place in an ocean that is faced with overfishing, acid rain, nutrient pollution from fertilizers and climate change, among other problems.
There have been many reports about jellyfish numbers increasing in the past few years; some researchers think it is part of a larger trend, while others say it may be just a numerical fluke.
Most agree, however, that more data is needed before coming to a definitive conclusion.

Gershwin, a research scientist with the Commonwealth Scientific and Industrial Research Organisation who specializes in jellyfish, recently wrote about her findings in a book called "Stung! On Jellyfish Blooms and the Future of the Ocean" (University Of Chicago Press, 2013).
The book, which is aimed at a general audience and is not peer-reviewed, details dozens of studies that Gershwin read and concludes it's possible that ocean conditions are ripe for a jellyfish takeover. [Image Gallery: Jellyfish Rule!]

Drifters of the deep from Eugenia Loli

"What we see in the areas that are the most damaged from numerous different disturbances, we see these jellyfish bloom problems," Gershwin told LiveScience.
In the Sea of Japan, for example, jellyfish are drifting in from China, where reports indicate the country is facing massive overfishing and pollution, as well as coastal construction where jellyfish polyps (or young) can find a home, Gershwin said.

Some researchers say that overfishing removes other species that compete for the same food jellyfish eat, such as plankton.
Gershwin thinks that overfishing, climate change and a combination of other factors are clearing the way for a jellyfish takeover. Jellyfish are said to prefer warmer oceans; no direct link has been found for why acidification would benefit them, according to a 2008 paper in the journal Limnology and Oceanography, but some researchers say jellyfish increase in abundance in acidic conditions.
"The jellyfish seem to be the ones that are flourishing in this while everything else is suffering," Gershwin said.

The trouble with tracking jellyfish, however, is it's hard to estimate populations on sight.
Given the creatures are underwater, there are few records right now — let alone from the past few decades — indicating the extent of jellyfish populations and how they are changing.
Gershwin acknowledges that more "good, brilliant, innovative, creative scientists" are required to find the links between jellyfish population increases and their causes.

Jellyfish - (song is Come Back When You Can by Barcelona) from Jon Rawlinson

Boom-and-bust, or not so much?

In one 2012 analysis of jellyfish population reports dating back to the 19th century, researchers publishing in the journal Proceedings of the National Academy of Sciences unveiled a 20-year cycle in jellyfish abundance.
Another paper published that year in the journal Hydrobiologia, however, tracked jellyfish increases at the most surveyed "large marine ecosystem" locations since 1950.

The paucity of data means it is difficult to draw any conclusions about what is happening, jellyfish researcher Steven Haddock, of Monterey Bay Aquarium Research Institute in California, told LiveScience.
"It's not to say climate change isn't happening. It's not to say jellyfish [population increase] is not happening," Haddock said.
"But I think there are so many causes that would come before climate change that it doesn't seem that productive. It sounds to me like scary rhetoric to try to get funding, or to get people all excited about it."

jellyfish from Tristan Greszko

Scientists will need at least a decade's more work before drawing any definitive conclusions about population numbers, Rob Condon, a marine scientist at Dauphin Island Sea Laboratory in Alabama who headed the cycle paper, told LiveScience in a previous interview.

Haddock encourages anyone interested in jellyfish to submit sightings to his group, JellyWatch.org, to help move the research along.
Gershwin, meanwhile, worries that waiting may make it too late to stop the invasion, if it is indeed happening.
"We're conducting this enormous global experiment, damaging the oceans, and the ocean is our life support system," she said.
"As crazy as it sounds, I think humanity needs a rethink," Gershwin added.
"We need to really think about how important is that life support system, how important is food from the ocean to us. Are we comfortable polluting it and poisoning it and wiping it off the face of the Earth? Is that the result we want for our future and our kids and our grandkids?"

I Had a Dream I was a Jellyfish Floating Through Space from mike ambs

Links :

• CNN : Jellyfish taking over oceans, experts warn / Jellyfish love the oceans we pollute
• GeoGarage blog : World's largest jellyfish / Jelly fish 'early warning system' to be launched in French Riviera / Have jellyfish come to rule the waves / Jellyfish lake, Palau / Jellyfish swarms: menacing or misunderstood?

Nautical Charts, by G. R. Putnam (eBook)

The Project Gutenberg EBook of Nautical Charts, by G. R. Putnam

Read this book online : download this eBook

member of the American Society of civil engineers
director of Coast Surveys, Philippine islands, 1900 to 1906

In preparing the material for a lecture on Charts for Columbia University, the writer was impressed with the fact that although nautical charts are mentioned or discussed in many publications, there was not found any one which covered the general subject of their origin, construction, and use.

CHART OF NORTH ATLANTIC OCEAN, BY JUAN DE LA COSA, 1500.
EARLIEST EXTANT CHART SHOWING AMERICA.

In the countries of the world more than a million copies of such charts are now issued annually.
A considerable portion of the human race is interested directly or indirectly, whether as mariners or passengers or shippers, in navigation upon the sea.

THE SIGSBEE SOUNDING MACHINE ON A SURVEYING VESSEL.

Aside from supplying a handbook for those who might have a general interest in the subject, it was thought that a discussion of charts might lead to further consideration of the principles governing their construction.

This paper has intentionally been made as non-technical as seemed feasible in treating a somewhat technical subject.

CONTENTS

	PAGE
List of Books or Papers bearing on Nautical Charts and related Subjects	vii
Charts and Maps	1
Collection of Information for Charts	31
Preparation of Information for Charts	67
Publication of Charts	84
Correction of Charts	97
Reading and Using Charts	112
Use of Charts in Navigation	124
Publications Supplementing Nautical Charts	154
Index	161

Massive Antarctic iceberg sets sail

acquired November 10, 2013

Between November 9–11, 2013, a large iceberg separated from the calving front of Antarctica’s Pine Island Glacier. 
Scientists first detected a rift in the glacier in October 2011.

By July 2013, infrared and radar images showed that the crack had cut completely across the ice shelf.

New satellite images now show that Iceberg B-31 is finally moving away from the coast.
The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite acquired these natural color images of Pine Island Glacier on November 10 (top) and November 3, 2013.

Dubbed B-31 by the U.S. National Ice Center, the new iceberg is estimated to be 35 kilometers by 20 kilometers (21 by 12 miles), roughly the size of Singapore.

A team of scientists from Sheffield and Southampton universities will track the 700 square-kilometer chunk of ice and try to predict its path using satellite data.

 

 acquired November 3, 2013
see NASA : Major Iceberg Cracks off Pine Island Glacier

From LiveSciences

After lingering in its birthing bay for nearly six months, an Antarctic iceberg the size of Singapore is finally heading out to sea.

Strong winds blowing off the continent are pushing the giant floe away from its parent, the giant Pine Island Glacier, and the warming Southern Hemisphere's has melted the thick winter sea ice that held the block in place since July, said Grant Bigg, an ocean modeler at the University of Sheffield in the United Kingdom.

 >>> geolocalization with the Marine GeoGarage <<<

The latest satellite images show several kilometers (a couple of miles) of open water between the iceberg and the glacier, Bigg told LiveScience's OurAmazingPlanet.
"We've been waiting for this to happen," Bigg said.

acquired 13 November, 2013


acquired October 28, 2013

The enormous ice block took more than two years to calve (break off) from Pine Island Glacier.
A spectacular crack crossing the glacier was first discovered during a NASA IceBridge research flight in October 2011.
The iceberg broke free on July 8, 2013, measuring about 278 square miles (720 square kilometers), according to tracking by TerraSAR-X, an Earth-observing satellite operated by the German Space Agency (DLR).
Bigg recently received a grant to track the drifting floe, which could disrupt international shipping lanes.

For five years an international team of experts, led by NASA emeritus glaciologist Robert Bindschadler and funded by the National Science Foundation and NASA, planned and orchestrated a mission to drill through the floating ice shelf of the Pine Island Glacier. Finally they persevered over harsh weather conditions, a short Antarctic field season, and the remote location of the glacier, and installed a variety of instruments to measure the properties of the ocean water below the ice shelf.

Icebergs sailing into the ocean from West Antarctica may stay close to the continent's coastline, causing little hazard, or launch out into the Southern Ocean toward the Drake Passage near South America's Cape Horn.
Bigg and his colleagues plan to try to predict the iceberg's path up to a year in advance, based on ocean currents and prevailing winds.
The modeling will help the shipping industry improve ice warnings, he said.
Huge icebergs such as the spawn of Pine Island Glacier often shatter into several pieces, and Bigg's team will track and model the fragments if the chunk collapses.
Already, a few small pieces have broken off the west side of the iceberg as it moved in the past few days, Bigg said.
"Each of the last three years has seen a giant iceberg calve, from either Greenland or Antarctica," he added. "Being able to track and forecast the tracks of these huge blocks of ice will be a major benefit to the shipping industry, particularly as more ships begin to use polar waters, as Arctic sea ice melts. This ability is what we aim to develop."

Links :

• GeoGarage blog : Warm ocean causing most Antarctic Ice shelf mass loss / NASA Operation Ice Bridge : High and Low over the Rift / Glaciers calving : cause for worry ? / Birth of an Iceberg

Brazil DHN update in the Marine GeoGarage

1100 DO RIO ITARIRI A ILHEUS

2 charts have been added and 29 have been updated since the last update

DHN update November 6, 2013

• 810   PROXIMIDADES DO PORTO DE NATAL
• 910   PROXIMIDADES ITAPESSOCA
• 1100   DO RIO ITARIRI A ILHEUS     NEW
• 1101   PROXIMIDADES DO PORTO DE SALVADOR
• 1102   PORTO DE SALVADOR
• 1103   BAÍA DE ARATU E ADJACÊNCIAS
• 1110   BAÍA DE TODOS OS SANTOS
• 1402   DO PONTAL DA REGÊNCIA À PONTA DO UBU
• 1403   DA BARRA DO ITAPEMIRIM AO CABO DE SAO TOMÉ
• 1501   BAÍA DE GUANABARA
• 1513   TERMINAIS DA BAÍA DE GUANABARA
• 1550   BACIA DE CAMPOS
• 1711   PROXIMIDADE DO PORTO DE SANTOS
• 1821   BARRA DE PARANAGUÁ
• 1907   DA ILHA DO CORAL À ILHA DAS ARARAS
• 1909   DA ILHA DAS ARARAS AO CABO DE SANTA MARTA GRANDE     NEW
• 21060   DO ARQUIPÉLAGO DOS ABROLHOS AO CABO FRIO
• 21080   DO CABO DE SANTA MARTA GRANDE AO ARROIO CHUÍ
• 21600   DA ILHA MAIAÚ À TUTÓIA
• 22900   DE VITÓRIA AO CABO DE SÃO TOMÉ
• 2113   DE PORTO ALEGRE AO TERMINAL SANTA CLARA
• 2140   LAGOA DOS PATOS
• 303   DO CABO MAGUARI À MOSQUEIRO
• 4411   DA FOZ DO RIO TROMBETAS AO LAGO QUIRIQUIRI
• 4412   DO LAGO QUIRIQUIRI AO LAGO PARU
• 4413   DE ORIXIMINÁ À ILHA JACITARA
• 4414   DA ILHA JACITARA AO LAGO AXIPICA
• 4415   DO ESTIRÃO DO FRANÇA AO LAGO ARACUÃ
• 4416   DO LAGO ARACUÃ AO LAGO BACABAL
• 4417   DO LAGO SAMAÚMA AO LAGO MUSSURÁ
• 4418   PORTO TROMBETAS

 

Note : for info, the following 20 charts have been withdrawn from the DHN catalogue

• 40    DA BAIA DO OIAPOQUE AO RIO PARNAIBA
• 60    DO RECIFE A BELMONTE
• 70    DE BELMONTE AO RIO DE JANEIRO
• 90    DA ILHA DE SANTA CATARINA A MALDONADO
• 100    DO CABO ORANGE A ILHA DE MARACA
• 200    DA ILHA DE MARACÁ À ILHA DO MACHADINHO
• 205    DE MACAPA A ILHA DE SANTANA
• 210    PROXIMIDADES DA BARRA NORTE DO RIO AMAZONAS
• 310    DE SALINÛPOLES A BELÈM
• 311    FUNDEADOURO DE SALINOPOLIS
• 312    PROXIMIDADES DA BAÌA DE MARAPANIM
• 314    DO BAIXO DO ESPADARTE  A BOCA DA VIGIA
• 400    DO CABO GURUPI A ILHA DE SANTANA
• 1171    BAIA DE TODOS OS SANTOS CANAL DE ITAPARICA
• 1400    DO RIO DOCE AO CABO DE SÃO TOMÉ
• 1514    PONTA DA ARMACAO
• 1516    CANAL DO GALEAO
• 1805    BAIA DA BABITONGA SAO FRANCISCO DO SUL
• 2000    DE TORRES A MOSTARDAS
• 2200    DO RIO GRANDE AO ARROIO CHUI

Today 433 charts (481 including sub-charts) from DHN are displayed in the Marine GeoGarage
Don't forget to visit the NtM Notices to Mariners (Avisos aos Navegantes)