Some of the earliest tide gauges (which have given us some of longest sea level records in the world) were housed in specially designed huts. Because of their age, a lot of these buildings are of unique and interesting design. Below are a few examples.

From Wikipedia:

“The Kronstadt sea-gauge with the tide gauge pavilion is a zero-level of the Baltic system depths and heights. All depths and altitudes (even the heights of the flight spacecraft) in Russia and some other countries (former Russian Empire) are measured from the level of Kronstadt sea gauge. Yuri Gagarin, the first spaceman in the World, ironically said in 1967 that this is it the Hub of the Universe.”

The sea level has been measured at Kronstadt (although not always at the same location) since 1777, making it one of longest sea level records in the world.

Some more tide gauge buildings:

Ystad, Sweden. Sea level has been recorded here since 1887. Photo by Anders Lagerås.

Leixões tide gauge, Portugal. Built 1890.

Port Arthur, Tasmania, Australia. First recordings were made in 1841.

Waterfront clock tower – Cape Town, South Africa, built in 1882. Photo by Michael Coghlan.

Vernadsky hut, built 1958. Longest tide gauge record in Antarctica.

Stockholm-Skeppsholmen, installed in 1889. Sea level has been recorded in Stockholm since 1774. Photo by Thomas Hammarklint.

Newlyn’s tide gauge is located here. Operational since 1915.

The Tidal Observatory was established to determine the mean sea level used as the starting point for levelling in the UK. A brass bolt on the site is the benchmark for the whole of the United Kingdom. All Ordnance Survey map heights are referenced to this point.

The height of the benchmark was established over a six-year period from 1915 to 1921. Visual observations of water level on a tide staff were made every 15 minutes, 24 hours a day, 365 days a year. From the data collected over this period, mean sea level was caculated and this vertical level marked with the bolt.

Click to enlarge:

High tide 28 April 2013

Streeter’s Jetty 28 April 2013 at high tide

The Broome Airports Jet Blast mound at hightide April 2013

Paspaley Shopping Centre, Broome, 2013

The fish factory where I worked would sometimes have water inside at high tide, not today. It just reached the edge of the concrete on the right

These pics here are from 2012.

high tide April 2012

Streeters Jetty, high tide April 2012

April 2012

Then the slightly bigger tides in 2011 here:

2011 highest tide, Chinatown, Broome

Today, April 28, 2013, this was dry at high tide.

1960′s Chinatown, Broome

Broome Airport, highest tide 2011

Highest tide 2011, BOM buildings in background

High tide 28 April 2013

New Scafetta sea level paper separates and recognizes the natural oscillations behind background acceleration in tide gauge records

The result is that the real sea level accelerations are very small.  Some of the major papers claiming catastrophic sea level rise for the 21 century are strongly rebutted

Multi-scale dynamical analysis (MSDA) of sea level records versus PDO, AMO, and NAO indexes

N. Scafetta

Abstract

Herein I propose a multi-scale dynamical analysis to facilitate the physical interpretation of tide gauge records. The technique uses graphical diagrams. It is applied to six secular-long tide gauge records representative of the world oceans: Sydney, Pacific coast of Australia; Fremantle, Indian Ocean coast of Australia; New York City, Atlantic coast of USA; Honolulu, US state of Hawaii; San Diego, US state of California; and Venice, Mediterranean Sea, Italy. For comparison, an equivalent analysis is applied to the Pacific Decadal Oscillation (PDO) index and to the Atlantic Multidecadal Oscillation (AMO) index. Finally, a global reconstruction of sea level (Jevrejeva et al. in Geophys Res Lett 35:L08715, 2008) and a reconstruction of the North Atlantic Oscillation (NAO) index (Luterbacher et al. in Geophys Res Lett 26:2745–2748, 1999) are analyzed and compared: both sequences cover about three centuries from 1700 to 2000. The proposed methodology quickly highlights oscillations and teleconnections among the records at the decadal and multidecadal scales. At the secular time scales tide gauge records present relatively small (positive or negative) accelerations, as found in other studies (Houston and Dean in J Coast Res 27:409–417, 2011). On the contrary, from the decadal to the secular scales (up to 110-year intervals) the tide gauge accelerations oscillate significantly from positive to negative values mostly following the PDO, AMO and NAO oscillations. In particular, the influence of a large quasi 60–70 year natural oscillation is clearly demonstrated in these records. The multiscale dynamical evolutions of the rate and of the amplitude of the annual seasonal cycle of the chosen six tide gauge records are also studied.

Climate Dynamics, April 2013.

Check these from 2011, click to see full pic:

EGU 2013 will bring together earth, planetary and space science experts from around the world, providing a forum where geoscientists can present their work and discuss their ideas with peers.

We will be presenting a poster in the session “Climate: Past, Present, Future: Global and regional sea level rise and variability: from past to future”. The session aims to discuss various questions. For example, do we fully understand the reasons for global and regional sea level rise in the past, present and future? What is the role of ocean dynamics and fresh water flux from melting glaciers and ice sheets in determining patterns of sea level change? How unusual is the rate of present day sea level rise compared to recent centuries?

The session will include contributions from sea level studies using historical and recent measurements from tide gauges, satellites, ocean and earth models, with the aim of improving our understanding of past and present changes in sea level and better predicting future change.

The session is part of celebrations marking the 80th anniversary of Permanent Service for Mean Sea Level (PSMSL). There will be special emphasis on studies that have added to sea level science through use of the PSMSL and other national and international sea level data sets.

(View a .pdf of the poster)

Our poster (EGU2013-4922: CL4.5/OS1.7) describes the JISC project and how the digitisation of data contributes to long-term climate records.

Sheerness self-registering tide gauge

The drawing shows the arrangement in detail of the tide gauge house, trunk, gauge and clock. Notes on the drawing explain how the tide level is traced on the revolving cylinder using a marker, which is driven by the cog wheel, operated by the clock work.

Sheerness self-registering tide gauge gear diagram

The level of detail in the drawing is very impressive, with teeth very carefully drawn in some of the cogs, and someone has clearly put a lot of effort in to creating this piece of work, which is why it’s interesting to see that gauge is consistently spelt ‘guage’. I’m glad we now have spellcheck!

“Claims of the IPCC and related persons with respect to sea level changes is deeply biased and not based on actual observation. A total revision is necessary. Its purpose appears to simply be to scare people.” (Nils-Axel Mörner)

Schoolteachers do not have to worry that Americans driving SUVs are threatening coastal Cubafornians and the inhabitants of small islands. That should be great news but, of course, it is disappointing for fearmongers at the UN-IPCC and in Western academia. Much as Members of the Bakery, Confectionery, Tobacco Workers and Grain Millers International Union destroyed Hostess Brands, Inc., is it any Wonder self-defeating schoolteachers and their government union Ding Dongs are beating the Ho Hos out of America and running off Twinkie production to China where businesses are not penalized for polluting the air with the smell of baking bread? 

The IPCC is fundamentally corrupt. The only ‘reform’ I could envisage would be its abolition —Vincent Gray

The free enterprise system is beating against a powerful headwind of anti-Americanism, superstition and ignorance: 25% of Americans starting high school don’t finish and of those that go to college–6 years later 43% still have not graduated. The government-funded Education Establishment says–e.g., “The science on global warming and sea level rise is clear; we should waste no more time on that debate: capitalism is destroying the Earth.”

But, nonexistent global warming cannot cause the seas to rise. Just yesterday, 125 signatories to a November 29, 2012 ‘Open Letter’ to H.E. Ban Ki-Moon of the UN brought to the Secretary-General’s attention ”recently released data [U.K. Met Office] showing that there has been no statistically significant global warming for almost 16 years,” proving ”models are wrong by their creators’ own criterion.”

“We are told that the sea level is rising and will soon swamp all of our cities. Everybody knows that the Pacific island of Tuvalu is sinking. Al Gore told us that the inhabitants are invading New Zealand because of it.

“Around 1990 it became obvious that the local tide-gauge did not agree — there was no evidence of ‘sinking.’ So scientists at Flinders University, Adelaide, were asked to check whether this was true. They set up new, modern, tide-gauges in 12 Pacific islands, including Tuvalu, confident that they would show that all of them are sinking.

“Recently, the whole project was abandoned as there was no sign of a change in sea level at any of the 12 islands for the past 16 years. In 2006, Tuvalu even rose.” (Dr. Vincent Gray)

Back in 2009 Bob Carter observed that, “using several fundamentally different mathematical techniques and many different data sets, seven scientists all forecast that climatic cooling will occur during the first decades of the 21st century,” and that, “Temperature records confirm that cooling is under way.” Still, we see a sleepy and dopey society being egged on with irrational fears about rising oceans that will wash away civilization. We are supposed to elect secular, socialist liberal fascists to high public office to kill more jobs. We all should, as Carter quips, “welcome a new source of income based on an invisible, colourless, odourless, tasteless and often unmeasurable gas. No commodity changes hands during its trading, and should carbon dioxide emissions actually decrease because of the existence of a carbon dioxide market (which is highly unlikely), the odds are that it will have no measurable effect on climate anyway…”

Instead of trying to exploit the misery of those who have suffered through natural disasters the above signatories advised that instead of worrying about ”climate shocks” the Secretary should understand it, ”would be worse if the world cooled than if it warmed.” Anyone who is up to date with the current scientific knowledge of climate-related matters agrees with the signatories above that the ”incidence and severity of extreme weather has not increased,” and that “funds currently dedicated to trying to stop extreme weather should therefore be diverted to strengthening our infrastructure so as to be able to withstand these inevitable, natural events, and to helping communities rebuild after natural catastrophes such as tropical storm Sandy.”

Over the years, as I have learned more about the data and procedures of the IPCC, I have found increasing opposition by them to providing explanations, until I have been forced to the conclusion that for significant parts of the work of the IPCC, the data collection and scientific methods employed are unsound. Resistance to all efforts to try and discuss or rectify these problems has convinced me that normal scientific procedures are not only rejected by the IPCC, but that this practice is endemic, and was part of the organization from the very beginning. (Dr. Vincent Gray)

What realistically would be the impact on the level of the seas even if humans were causing global warming? To answer we need only look at the impact of natural global warming.

There are physical limits for how fast ice can melt. The maximum rates recorded were those related to the melting of the glaciers of the Last Ice Age. The corresponding sea level rise amounted to 10 mm/year or 1 m per century. This figure sets the ultimate frame for possible sea level changes. 

Consequently, all claims of a sea level rise by 2100 exceeding 1 m can directly be discarded as physically impossible. Real changes must be significantly smaller.

The Little Ice Ages and Solar Minima in 1440-1460, 1687-1703 and 1809-1821 had little to insignificant effects on sea level, despite significant expansions of the alpine glaciers and Arctic ice cover, and sea surface cooling. (Professor Nils-Axel Mörner)

For some added perspective we should consider the groundless predictions of unnatural sea level rise that global warming junk science peddlers want us to find worrisome (e.g., 11 mm over two decades) to rises of 300 feet (>90 meters) since the last BIG Ice Age, as follows:

“Thirty miles west of Holmes Reef and sixty miles east of the Great Barrier Reef lies an underwater mountain or seamount whose peak is 120 feet below the surface. During the last ice age when sea level was as much as 300 feet lower than at present this was a high island. Today it is an unnamed circle of dotted line on the chart surrounding the number 36 representing the depth in meters. With satellite navigation receiver and echosounder we find it and drop anchor. Accompanied by prolonged rattling and clanking most of a hundred meters of chain disappears down the hawse pipe and I lock the winch. In a minute the dangling chain draws out ahead to a taut forty-five degrees and we swing to, headed into a two knot current…” ~Walter Starck

America’s children are the biggest losers in the Big Bird-educated cash for clunkers liberal Utopia of the Left.

A wake up call courtesy of the “party of government” that brought dead and dying Old Europe to the point of hearing its own death rattle is palpable — and, after all of the “revenue” enhancements to a bloated government have resulted in a clinkered society that is being dragged down the swirling porcelain vortex — as the EU approches the fiscal cliff, their message to America is simple:

“…no issue of global urgency has tanked quite as quickly as the warming of the earth’s climate.” (Spiegel staff)

On Thursday, Guy Wöppelmann from the University of La Rochelle LIttoral ENvironnement et Sociétés group will give a presentation on “Historical Sea Level”. We have prepared a poster that will accompany this workshop based on our efforts for the JISC content programme.

Rescue of historical UK sea level charts and ledgers poster

We hope this is the first step in forging closer links with the ACRE community, and we can learn from their experiences to improve data archaeology in the global sea level community, through our work with the Global Sea Level Observing System (GLOSS) programme.

Bristol Temple Meads (image taken from Russell Ede′s Flickr photostream and used under Creative Commons)

One of the first questions asked was “What is your goal for the end of this project?”

We would like to carry on with digitising analogue records. We have more historic charts in our archive, and we want to work with international programmes such as The Global Sea Level Observing System (GLOSS) data archaeology group to explore future opportunities and make use of emerging technologies.

We would also like to ensure that the digitised data and resources that we have created under the JISC eContent programme are being made use of. I managed to pick up a few pointers on how to embed our OERs in academic teaching at the workshop. It’s not enough just to make our resources available; we need to put them where the users are. As well as putting the OERs on our website, we will look at putting them on university websites as a start. If we are to produce OERs for a wide range of academic users, from schools and colleges to universities, we need to make sure that the lesson plans will fit in to the curricular and the subjects being taught and are tailored to the right audience.

Some of the documentation provided at the workshop can be found on the JISC Business Modelling and Sustainability webpages.

Sea level has been rising cm/yr, based on measurements of sea level rise from 23 long tide gauge records in geologically stable environments. (Photo credit: Wikipedia)

If you only watched the presidential campaigns, it would have been hard to believe that we actually live on a changing planet. Due to the false “debate” over the causes and consequences of human-induced climate change (the entire “debate” is financed by retrograde energy companies), President Obama rarely even mentioned our need to address the critical problem of a changing climate that is fueling drought, super-storms (e.g. Sandy), sea-level rise and ocean acidification.

But during his victory speech President Obama made a statement that stunned environmentalists.

“We want our children to live in an America that isn’t threatened by the destructive power of a warming planet,” he said.

Hurricane Sandy was a game changer on building consensus that our quickly evolving climate cannot be ignored and that its impacts has very real consequences. So in anticipation of the road ahead for protecting our coast and ocean, here are the top issues we need to address in 2013 and beyond.

Mean surface temperature change for 1999–2008 relative to the average temperatures from 1940 to 1980 (Photo credit: Wikipedia)

Climate Change: Hurricane Sandy showed us the very real consequences of warming temperatures, sea-level rise and the rise of destructive super-storms. Surfrider Foundation activist Mark West argues that, “Since superstorm Sandy, I think two issues are critical: rising ocean temps from global warming and coastal restoration projects.”

What is clear is that addressing the causes and consequences of climate change has to be a top priority. In San Diego, cities such as Chula Vista have already embarked on climate adaptation planning (I was a member of the advisory committee) that should be a model for San Diego County and even nationally.

Changes in sea level during the last 9,000 years (Photo credit: Wikipedia)

San Diego Foundation also coordinated a sea level rise adaptation strategy with the particpation of coastal cities and nonprofit organizations.

Ocean Acidification: While this is a consequence of human-induced climate change, the increase in carbon in our oceans is literally changing the chemistry of our oceans.

Ken Weiss recently reported on the issue of ocean acidification:

Rising acidity doesn’t just imperil the West Coast’s $110-million oyster industry. It ultimately will threaten other marine animals, the seafood industry and even the health of humans who eat affected shellfish, scientists say. The world’s oceans have become 30% more acidic since the Industrial Revolution began more than two centuries ago. The ill effects of the changing chemistry only add to the oceans’ problems, which include warming temperatures and expanding low-oxygen “dead zones.” By the end of the century, said French biological oceanographer Jean-Pierre Gattuso, “The oceans will become hot, sour and breathless.”

Coastal Restoration: San Diego has always been a national and even global leader in coastal restoration efforts. But we need to do more in the way of restoring our wetlands, watersheds and natural dune systems in order to strengthen our natural defenses against sea level rise and help to sequester the increasing amounts of carbon in our atmosphere. Additionally, restoration projects can increase our access to open spaces and trial systems that keep us healthy as well as protect fish and wildlife populations.

Stones on a Rocky Ocean Beach (Photo credit: epSos.de)

Sand Replenishment: For Oceanside surfer Rick Hahn, our biggest coastal issue is, “The consequences of constructing civilization in extreme proximity to our beaches, bays and waterways.” In many cases government agencies have only come up with one solution to that problem—dumping huge amounts of expensive sand on our coastline, often prioritizing the wealthiest coastal communities due to their capacity to hire expensive and well-connected sand lobbyists to game the system. However, what we saw with Sandy’s storm surge was the futility of spending billions of dollars on wasteful and largely pork-barrel sand replenishment projects. We need to rethink these projects so that they are smaller, more strategic and less costly.

This is especially the case in Southern California where the Army Corps of Engineers is proposing to spend a quarter of a billion dollars to dump sand on small patches of beachfront in Solana Beach, Encinitas and San Clemente. SANDAG planners also need to evaluate their current project in order to identify ways to reduce impacts to critical reefs and design future projects in a way that enhances rather than destroys surfing areas. We need a national debate on the most effective ways of preserving our beaches while maintaining our fiscal health.

Change in sea water acidity pH caused by anthropogenic CO 2 between the 1700s and the 1990s (Photo credit: Wikipedia)

Marine Protected Areas: With the enactment of a new system of state marine protected areas (MPAs)throughout our coastline, California has become a global leader in strategically preserving our most critical coastal and marine ecosystems. There is no better way to cost-effectively preserve our finfish populations than investing in the conservation of their spawning grounds. It is important to help to restore our new MPAs in order to bring back our commercially valuable fish and shellfish populations and preserve our treasures of the sea.

Fish populations returned more than 460% in the Cabo Pulmo MPA in Mexico.

Coastal Pollution: We have to continue reducing the flow of polluted runoff and plastic from our watersheds into the ocean so that we don’t have to worry about getting sick when we play in the ocean. Watershed and wetland restoration help in this effort, but it is everyone’s job to Think Blue.

There are a host of other critical issues including seismic testing, oil drilling in the Arctic and Gulf of Mexico, preserving endangered marine wildlife such as sharks, marine mammals and sea turtles, and the expansion of offshore drilling.

According to the BBC news website, the tidal surge reached a record height of 13.7ft (4.15m) in Manhattan.

The worst flood to hit the United Kingdom was the North Sea flood of 1953, when a high spring tide combined with strong winds to create a storm surge. The water level in some places exceeded mean sea level by 18.4ft (5.6m).

We have several original charts in our archive that record the storm, including these two from Southend and North Woolwich. The Southend chart shows a height of over 15ft above ODN, and the North Woolwich chart records a height of nearly 17ft.

Historic records are important for creation of future defences and planning disaster prevention. The effects of the storm eventually led to the building of the Thames barrier and the charts would have provided important data used in the construction of the barrier and other defences.

These floods have mainly been caused by the heavy rain. The most dramatic inundation from the sea, so far, may have been the sea foam pushed on shore near Aberdeen, a result of high winds blowing shoreward from a choppy sea. However, flood forecasters have been keeping a particularly close watch on the elevated levels of tidal rivers, which could be catastrophic when combined with a high tide.

According to the Environment Agency (EA), coastal flooding is flooding that “results from a combination of high tides and stormy conditions. If low atmospheric pressure coincides with a high tide, a tidal surge may happen, which can cause serious flooding.“

Sea level data can help our understanding of coastal flooding in a number of ways. The Met Office runs a computer surge model (PDF), which incorporates modern real-time tide gauge data and will alert the EA if the forecast comes close to a danger level.

Historic tide gauge data is useful for ascertaining the frequency of storm events. These data can be used in planning future flood defence measures. The EA ran the Thames Estuary 2100 project to develop a long-term tidal flood risk management plan for London and the Thames estuary. Historic sea level data from 6 tide gauges along the Thames was quality controlled by BODC and used in the project.

Sadly, there was little associated metadata with the films, which will make the tracing of copyright owners interesting! We will watch the films in the hope that there may be credits on them that could help us identify the copyright owners. The next step will be to see if the films’ titles generate any results in online searches. Some of the documentaries may be listed in the catalogues of the British Film Institute (BFI), for example. The JISC Briefing Paper on Managing Orphan Works (PDF) lists a number of searches an organisation could carry out. Hopefully most of the scientific footage will have been shot by a camera operator who was an employee of our Research Council.

The films are in a variety of formats. The earliest one we can date is from 1966 on 16mm film stock, though others may be older. The most recent film is from 1986, shot on super 8 film. Technical obsolescence is an critical issue to consider when planning long-term stewardship of data. Because of the age of the formats used, we’ve had a bit of trouble trying to track down the right kind of projectors to allow us to watch all of the footage.

Sailing relies on accurate tidal data recording

Britain’s triple Olympic sailing gold medallist Ben Ainslie has been quoted as saying:

“When I started sailing as a youngster, trying to qualify for the Olympics at Atlanta in 1996, there was no funding in place at all. When I received the Olympic funding in 1997-98, it effectively gave me an extra £20,000 a year as a top performer. I have absolutely no doubt in my mind that sailing and all the Olympic sports would be a lot poorer without that level of investment. Looking at the sport we had then compared to the sport we have now it’s almost unrecognisable: all the physio, support on the water, meteorology and tidal analysis is there because of the cash we get now.”

As part of their preparation for major events, Olympic sailing teams gather detailed information about the local sea conditions (currents and tides), to give them every possible advantage on the day. The custom tidal analyses the teams use require quality-controlled sea level data.

It would be nice to think that perhaps the NTSLF tide gauge at Weymouth may have helped provide data for the tidal analyses that allowed our athletes to sail to victory.

During the Olympics, the Met Office are generating daily forecasts of tidal information for the race area.

In 2003 we deployed a tide gauge that was recovered today after attempts in 3 different years to do so failed. Discovery Harbor near Fort Conger was the most northern location at 81 42’ North and 64 1’ West of a large moored array placed in 2003. It was at Fort Conger, that Lt. Greeley of the U.S. Army waited in vain for a supply ship that never arrived, but this sad story is for another day and I like to write about happier news: Our 2003 tide gauge lay in wait for 9 years and 1 day precisely. A 2006 attempt to reach this northern location by ship failed on account of heavy ice cover, a 2007 attempt by helicopter succeeded to establish acoustic communications, but failed to recover the sensor package, and a 2009 attempt by ship failed again because of difficult ice conditions.

The odds of a recovery were slim, but 4 hours ago a crew of five found the tide gauge the same way that skilled fishermen of Newfoundland recover lost traps and fish for halibut: with a line of hooks operating small ships smartly. Chief Officer Brian Legge, Seamen Derick Stone and Carl Rose, as well as scientists Ron Lindsay and Jonathon Poole found the proverbial needle (read tide gauge) in the hey stack (read Arctic Ocean). The entrance to Discovery Harbor was guarded by yet another ship-sized piece of Petermann Glacier ice, this one grounded, as well as several large and small sea ice floes, all moving rapidly with the tides and currents. Even navigating the zodiac through this maze to a fixed location was a major accomplishment.

The long-lost tide gauge is a 2 feet cylinder filled with electronics, but 9 years moored to the floor at 20 meter depth turned it into a complex biology habitat attracting wild life much like the artificial reefs created along Delaware by sunken New York City’s discarded subway trains. Mollusks, seaweed, clams, barnacle, algae, and bacterial slime all attached themselves to every surface. Arctic shrimp perhaps feeding on algae or slime were captured along with the gauge. Seaman Derick Stone, who has never seen an Arctic shrimp (neither have I), quickly brushed it away and back into the ocean muttering something about  “Scorpions in the Arctic.” A second specimen was captured alive and returned to the ocean after a brief inspection. It was agreed, that there was no enough meat on this 2-inch long and skinny shrimp

As a sign of respect to the gods of the icy seas a majority of PhDs aboard solemnly swore to give the long lost sensor 3 days of rest before stripping it bare to reveal its guts, check health and status and retrieve recordings. Pranksters aboard this ship, at least one with a PhD, already alerted me to schemes of hostile capture and ransom requests; I suspect ransom to be paid in treasures, valuable certificates, and screech. Little do these pranksters know of web streaming, local area networks, advanced image processing, and other counter-intelligence operations … to be continued.

P.S.: Oh, we also completed section work (temperature, salinity, water samples) in Robeson Channel to the north of Petermann Fjord where a few segments of Petermann Glaciers former ice shelf are both grounded and moving off the coast of Greenland. Presently off Cape Baird to perhaps recover an automated weather station to be placed instead at Joe Island at the southern entrance to Petermann Fjord, weather permitting. We got 40 kts winds from the south, braking waves, as well as balmy air temperatures of 4 degrees Celsius or so.

From chart to digital data

The digitised data are from Tilbury, covering the period 28/12/1984 to 12/10/1989. They started off as paper charts. One of the interesting aspects of these charts is that they show the effect on the water level of the closure of the Thames Barrier. This demonstrates how important it is that the digitisers have knowledge of where the charts come from and the environmental processes that can affect the operation of a site. If these charts had been digitised without the metadata (information about the data such as location, instrument type and date) then these strange-looking events might have been mistaken for instrument malfunction and flagged as bad data.

We’ll now begin carrying out quality control on these data. We will compare them to data from nearby locations (so-called buddy checking), look at previous data from the same site and compare the data with a harmonic analysis. I’ll talk more about our quality control procedures in a future post, but just wanted to inform everyone that we’ve now got some new digitised content!

One of the first references to the observation of the tide in Britain is in “Opera de Temporibus”, by the early Christian monk (The Venerable) Bede, where he comments on the “union of the ocean with the orbit of the moon”. More importantly, he points out that high tide does not occur at the same time everywhere around the coast of Britain, but instead progresses round the country (2).

The first known written tide table for European waters is for “flod at london brigge” (High Water at London Bridge) and appears in a 13th Century manuscript, now in the British Museum, that originally belonged to the Abbey of St. Albans.

In the first half of the nineteenth century, the British naval and commercial fleets significantly extended their territory. As British maritime interests expanded, correct tide tables, which require a correct theory of the tides, became essential. As technology advanced, self-recording instruments appeared. This coincided with an emphasis on quantitative measurement (3).

Plate from the first volume of Nautical Magazine (1832)

The tide gauge at Sheerness was the first self-registering tide gauge to actually record data. It was constructed by J. Mitchell, a civil engineer. The earliest tide gauge data we in our archive comes from this gauge.

You’ll find more information on the history of tides and tidal observation in these books:

(1). Pugh, D. (1987) Tides, surges and mean sea level. John Wiley & Sons Ltd.
(2). Cartwright, D. (2000) Tides: A Scientific History. Cambridge University Press.
(3). Reidy, M. (2004) Gauging Science and Technology in the Early Victoria Era, in: Rozwadowski,H. & Van Keuren, D. (eds) The Machine in Neptune’s Garden: Historical Perspectives on Technology and the Marine Environment. Science History Publications, pp.1-35

Sea levels have risen by 0.07 inches a year from 1961 – 2003 according to tide gauges.

Most of the unimaginable amount of water pumped out of underground aquifers, rivers and lakes for human consumption eventually finds it way to the sea.

It is estimated that 42% of the rise in ocean levels can be attributed to human water use.

In 2006, Ivan Haigh contacted BODC. He was working on a Ph.D at the University of Southampton with the topic ‘Extreme sea levels in the English Channel’. The study relied on analysing high-frequency sea level data (for data to be ‘high-frequency’, the readings
need to be an hour or less apart). He would then analyse the data and attempt to calculate

• Mean Sea Level (MSL)
• The probability of future extreme sea level events

This kind of research requires long time series. As Ivan says on his blog:

“The study of extremes is more difficult than research into MSL changes owing to the general lack of access to long, high frequency and quality-controlled datasets. Records of about 35 years (i.e. about two 18.6 nodal cycles) are needed to accurately determine changes in extreme levels, as the influence of the nodal cycle can significantly bias trend estimates in shorter datasets. At the start of the study, there were only two tide gauge stations on the UK south coast (Newlyn and Dover) with sea level records matching these requirements and a further seven sites on the northern French coastline.”

For background on the 18.6-year nodal cycle, see this Wikipedia entry on tidal analysis.

In order to increase the timespan of data series available for study, Ivan carried out a data archaeology exercise. The first step was to identify what data existed in analogue formats. He asked BODC about sea level data for Southampton that he knew we held in chart form. He then took these charts and had them digitised, converting the data into a useable format.

Taken from Haigh, I.D., Nicholls, R.J., Wells, N.C., 2009a. Mean sea-level trends from English Channel tide gauge records and their wider context. Continental Shelf Research, 29, 2083-2098

The data archaeology exercise was very successful and in total 173 years worth of digital data for the South Coast were created. The record for Southampton was extended back to 1937.

The British Oceanographic Data Centre (BODC) is a national facility for managing data concerning the marine environment. We’re part of the Natural Environment Research Council (NERC). NERC is the main UK agency for funding and managing environmental science research.

Our marine data management involves

• Working alongside scientists during marine research projects
• Quality controlling and archiving data
• Distributing data to scientists, education, industry and the public

We deal with different data types (e.g. biological, chemical, physical, geophysical) from projects all over the world. One of the areas where we have a lot of expertise is in sea level data. We hold over 8000 site years of digital sea level data from 671 locations worldwide and have acted as the sea level data centre for several major sea level observing programmes.

We also curate digital data from the UK National Tide Gauge Network. The network consists of 43 tide gauges around the UK. It was set up in 1953 after storm surges caused severe flooding along the east coast of England. We’re responsible for quality controlling, archiving and distributing these data.

As well as this, we hold a very large archive of analogue sea level readings, in the form of paper charts, notebooks and microform negatives. These records contain observations from around the world.

Long-term sea level records are used in many areas, including:

• Oceanography (ocean currents, tides, surges)
• Geodesy (national datum),
• Geophysics and geology (coastal land movements)
• Climate studies (sea level rise)

The Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) is currently underway. The science of climate prediction requires reliable long-term data to extrapolate from. This is one of the reasons why recovering unique and irreplaceable long-term climate records is crucial. As some records held at BODC go back over 100 years (in one case, as far back as 1832), it’s very important that we provide long-term care for our long-term records.

(Click on any small photo to open gallery and see enlargements)

It is time for a change of topic I think. Not that the Old Buildings topic is exhausted by any means. I just feel that variety is the spice of life.  So why waste opportunity when it knocks. Anyway, as it turns out this topic is closely related to “Old Buildings”.

My wife and I visited the V&A waterfront in Cape Town today. That was after we stopped off on the Grand Parade to photograph the Cape Town City hall Bell Tower and clock.

It was a cloudy day in Cape Town. Lovely and cool after the pressing heat wave of the last few weeks.

Cape Town City Hall:  It’s foundations were laid at the turn of the 18/19th century and it was opened in July 1905. It boasts an Italian Renaissance style and classical façade, with the  clock tower built to scale – exactly half the size of London’s Big Ben.

The Lutheran Church Clock Tower:   In 1771, Martin Melck gave his fellow Lutherans permission to hold services in his barn in Strand Street. A few years later, consent was given to convert the barn into the Lutheran Church. The church’s carved pulpit by Anreith has become famous.  Source: www.cape-town.net/html/citycen2.htm

The V&A waterfront Clock Tower (circa 1882):  In its heyday this was the port captain’s office. He could check the comings and goings of the harbour from the comfort of his mirrored bureau.  The red-brick Clock Tower was built in a Victorian-Gothic style.

The 2nd floor is a mirror room, which allowed the Port Captain to have an all-round v iew of all harbour activities. On the ground floor is a tide-gauge mechanism which was used to check tide levels. Restoration of the Clock Tower was completed in 1997.

It is wonderful to see the V&A waterfront so busy. Tourists are all over and restaurants are mostly full. We were lucky to get a table fairly quickly at the Quay 4 restaurant where we enjoyed a lovely lunch of, yes you guessed it, fish & chips! I had the catch of the day – Sea Bream (Kolstert), while my wife settled for Hake.

Next week the plan is to search out more buildings with clock towers. Until then, have a good week and drive safely wherever you go!

NOAA Ship Rainier

Mission: Hydrographic Survey
Geographical Area: Alaskan Coastline, the Inside Passage
Date: Friday, September 23, 2011

Weather Data from the Bridge

Clouds: Overcast
Visibility: 10 Nautical Miles
Wind: 25 kts
Waves: 1- 2 feet
Temperature
Dry Bulb: 10.3 degrees Celsius
Barometer: 1002.6 millibars
Latitude: 55 degrees North
Longitude: 133 degrees West

Science and Technology

Rainier Skiff Boat

Now that there is a small window of clear weather I am able to go out on one of the small boats called a skiff.  This boat holds about 8 people max and is mainly being used to move people and equipment around to the different stations.  The night before I was scheduled to leave I learned that my task on this outing was going to be reading the tide staff every six minutes for 3 hours.  I know the initial reaction might be, “Why would you want to do that?”  Well, it is actually really important for the data that we are collecting.  When the equipment (primary benchmark, tide gauge, tide staff, orifice, etc.) was placed on Block Island this allowed the scientists to be able to know what the actual water levels would be for the launches when they head out. This in turn, is important because the height of the water levels will affect the data that is being collected on the launches (survey boats).  The first few hours started giving us pretty good data, but then we stopped getting anything at all.  We had been hit by a storm so numerous scenarios were being brainstormed so we could be prepared for anything that we might find when we got there to fix the problem.

Garmin Route to Block Island Courtesy of Todd Walsh

We traveled from the Rainier to Block Island, which was about 19 miles away.  When we got there the tide staff was in good shape and even the antennas and GPS looked good.  However, upon further inspection they found that there were glitches in the software files that had made it stop collecting data.  Once they got it going again, my partner Starla, and I went straight to work collecting the high and low wave of the tide.  We then used this data to calculate the mean (average) of the two.  We had to collect this data every six minutes for three hours because that is the same data that the tide gauge is collecting.

Tide staff at Block Island

We had to use GPS time–which was the same as the tide gauge–and not our own watches. This is because we needed the same time stamp for the data, which allows the scientists to see that the data was collected at exactly the same time.  Scientists can then look to see if the data we collected and the data the tide gauge collected are the same or if there are errors.  Then, they can see if it was human error or if something is still wrong with the tide gauge.  These first three hours were very important for the data collection, but the scientists will continue to monitor the station every three to four days for one hour throughout the month to make sure it is collecting data properly.

Mrs. Heins Taking Tide Staff Measurements

As we collected the data, one of us would watch the clock while the other would very intently watch the tide staff.  Once it would come to the time we would have to collect the data she would say “Mark!” and that would be my cue to note the high and low of the wave against the tide staff.  I would tell her my observations up to four digits, such as 1.967 meters.  However, because we would use quick observations to collect our data, our precision would probably be only to three significant figures. Significant figures are digits of a number that carry meaning and factor  into its precision. Starla would record the data and then we would wait six minutes until the next time to make our observations. When we were done, we downloaded the data from the tide gauge, packed up the skiff, and head back to the Rainier. Overall, it was a really great day being able to collect this important data and contribute to the mission of the ship.

Heading Back to the Rainier

Personal Log

Calculating Radar Ranges on a Nautical Chart

Math, math everywhere!!  Since the first day I have been on the Rainier I have seen math being used all day, every day.  Even though I don’t specifically teach math I do integrate it within science and social studies.  However, I have heard from students, “Why do I have to learn this?” in regards to their math homework.  There isn’t always enough time in the day to give a thorough explanation of how different math skills are used in the real world.  However, from my past NASA experiences and now with NOAA on the Rainier, I am here to tell you that once you enter the real world, especially if you enter a science, math or engineering field, then you will be immersed in math.  It will become a part of your daily routine without you really realizing it.  One place where math is used constantly, and is also one of my favorite places on the ship, is the bridge.

Math is used in navigation, such as setting a course, calculating distances, speeds, and times.  I also got some practice with calculating radar ranges, which can give the officers their location based off of 3-4 points of land nearby.  GPS is being used all day, every day and there are multiple GPS systems in case one fails.  Again, the officers use this information in their calculations throughout the day while we are at sea.  When I have been collecting weather data on the bridge math is being used to calculate the wind speed and direction.

Finding an Azimuth

Then there are conversions being calculated because some of the charts are in meters, some are in feet, and some are in fathoms.  A fathom is used more for deeper water because 1 fathom equals 6 feet.  Because these are dealing with depths it is very important to make sure the conversions are correct so that the ship stays safe.  Then of course there is math used in other ways on the ship.  For example, the Executive Officer (XO) has to work with the ship’s budget, the cooks work with measurements in the galley, and the scientists work with math formulas as they process the data in their projects.

Overall, I highly encourage my students and any other young minds that are reading this to do your best in math and ask for help if you need it.  It can be an intimidating subject area at times, but if you want to work for NOAA, be a scientist, or engineer then it will be an important part of your job.  Once you have an idea of what kind of job you want to have when you get older, try to find out what kind of skills you need to have and start early.  See how the math is used in the real world, the job you are interested in, and learn how to have fun with it!

Student Questions Answered!

Animals Seen

Sea Lion

Whales (not sure of the species)

California Sea Lion

Moon Jellyfish

Question of the Day