Antarctica traced from space

From NASA

Antarctica may not be the world's largest landmass -- it's the fifth-largest continent -- but resting on top of that land is the world's largest ice sheet. That ice holds more than 60 percent of Earth's fresh water and carries the potential to significantly raise sea level. The continent is losing ice to the sea, and scientists want to know how much.

Antarctica's ice generally flows from the middle of the continent toward the edge, dipping toward the sea before lifting back up and floating. The point where ice separates from land is called the "grounding line." For scientists, an accurate map of the grounding line is a first step toward a complete calculation of how much ice the continent is losing.

Such a map is a primary objective of the Antarctic Surface Accumulation and Ice Discharge (ASAID) project. Researchers from NASA's Goddard Space Flight Center in Greenbelt, Md., led a team that used high-resolution satellite images, along with newly developed computer software, to trace the most accurate Antarctic grounding line ever compiled.

"This project has been a major achievement to come from the International Polar Year," said Robert Bindschadler, a cryosphere scientist based at Goddard who presented his team's work in June at the International Polar Year Oslo Science Conference. "This project included young scientists, it was an international effort, and it produced freely available data -- all from satellites."

Much public attention has been focused on the Arctic, where ice loss is accelerating. Antarctica, however, is also steadily losing ice. NASA satellites have shown ice losses around the entire continent, with pronounced changes in the northern region around the Antarctic Peninsula. The most significant changes are likely to occur at the intersection of the ocean and the ice sheets.

At what rate is Antarctica's ice is lost to the ocean? It's a tricky question because of Antarctica's immense scale. Previously, researchers calculated the speed of outflow from 33 of Antarctica's biggest outlet glaciers, but that accounts for just half of what is lost, as outlet glaciers makes up only 5 percent of the coastline.

The rest of the coastline might lose ice through icebergs that calve off from outlet glaciers or over land cliffs. Sometimes ice flows gently from glaciers that extend far into the ocean as floating ice shelves or skinnier ice tongues. In other cases, the ice never reaches the ocean at all.

To draw the new grounding line, the team of NASA and international scientists worked with a mosaic of high-resolution images of the continent from the Landsat 7 satellite. Using software developed by Goddard's Hyeungu Choi, the team collated and mapped points from previously mapped lines, high-resolution imagery, and some new information about surface elevation.

"Completion of this line was huge, as we connected 3.5 million geographic points around the continent," said Goddard's Amy Wichlacz, who popped a cork in celebration after eight months of meticulously connecting the dots.

The team found that the grounding line around the edge of the ice sheet follows a winding path 53,610 kilometers (~33,312 miles) long. The high-resolution imagery makes the new map more precise than previous assessments of grounding lines, which sometimes mistakenly included shadows and islands as part of the continental landmass.

The next step is to use satellite elevation data from ICESat to determine the ice thickness near the grounding line.

The new map and elevation data, along with thickness information (once complete), will be turned over to the National Snow and Ice Data Center in Boulder, Colo. Knowing where ice leaves the land, combined with the thickness of ice in the vicinity and speed of the ice, allows scientists to calculate how much ice is being lost.

Links :

• ASAID: Antarctic Surface Accumulation and Ice Discharge
• Landsat Image Mosaic of Antarctica
• NASA : New map of Antarctica's icy edge
  
• ScienceDaily : Oceanographers Call for More Ocean Observing in Antarctica
  

The oceans are in the Cloud

Riveting hydrographic innovations set the pace for change elsewhere

From Shipcrunch_5956n by Ryan Skinner

Read this, from Peio Elissalde of the little French geo-informatics outfit Marine GeoGarage: "[We're ushering in] a new era of nautical mapping services with the launch of a marine charts portal built on cloud computing technology."

It's probably the first time I've seen the "cloud computing" buzzword in the marine world.
What is cloud computing?
Basically, you plug into the information and services you want wherever you have Internet access.
All those things that you used to find on your hard drive or your company's proprietary servers?
Now they're in the cloud - huge server clusters run by the likes of Amazon, Microsoft, Google or IBM.

The crazy idea Marine GeoGarage had was to give marine chart users an online account, from which they can access the latest updated charts from a number of international hydrographic services.
The way Marine GeoGarage builds the chart views for users, and how users interact with them, uses cloud computing technology.

Elissalde put it best: "You don't own charts anymore, just use them and share them anytime, anywhere you are via computer, mobile phone or any other Internet device." Google Maps for mariners, in other words.

Meanwhile, another guy named Tim Thornton of TeamSurv has a complementary idea.
They want to crowdsource hydrographic data.
How?
If you put some sensors on any commercial ship or leisure craft to record depth and such, and gather this data based on its location, you have the foundation for making and updating marine charts. Imagine a hydrographic service with thousands of ships creating a firehose of new data, instead of a couple ships with multi-beam echo sounders mowing the proverbial oceanic lawn.

It's not too great a stretch to imagine TeamSurv feeding hydrographic data into the cloud, with hydrographic offices providing norms and quality certification, so suppliers like Marine GeoGarage can package value-added services.
Yes, both companies are initially focusing on the light marine market; that's where much of our innovation comes from.
In fact, there's every reason to believe the above model resembles the future.
Some chart suppliers are preparing themselves for a future a lot like this.

What can the rest of the industry learn from this example?
Anyone who can scale services worldwide around a core pool of data or functions, and fashion it into a subscription model service, for example, would be wise to explore a cloud model. Brokers, box-ship operators, even component suppliers, could exploit this.
What if you could log in to your vessel from any Internet connection and pull down real-time operating data, with comparisons to similar plants?

The core idea is turning what used to be assets that you had to own and maintain into services you basically rent.
Software's an obvious candidate.
Hardware and infrastructure will follow.
For one client, we held a workshop positing "Propulsion as a Service".
Cloud propulsion may be a bridge too far, but it gets minds racing.

For nerds interested in the full online chat between me and Elissalde of Marine GeoGarage, just click through:

[5/28/10 3:02:37 PM] redwood.skinner: Hi Peio!

[5/28/10 3:03:37 PM] redwood.skinner: Are you there?

[5/28/10 3:04:21 PM] Peio Elissalde: Hello Ryan

[5/28/10 3:04:33 PM] Peio Elissalde: Yes I'm ready to discuss with you

[5/28/10 3:04:38 PM] redwood.skinner: Right. I'll just fire away then

[5/28/10 3:05:05 PM] redwood.skinner: First question: who is this product meant for exactly?

[5/28/10 3:05:50 PM] Peio Elissalde: At firts, our website is dedicated to any sailor or mariner who plans to study his next trip at sea, comfortably installed at home.

[5/28/10 3:06:18 PM] redwood.skinner: in other words, primarily leisure craft sailors?

[5/28/10 3:06:55 PM] Peio Elissalde: Yes but we are not racists : so any mariner is welcome

[5/28/10 3:07:40 PM] redwood.skinner: ok. do i understand correctly that access to many charts is free, with access to others (chart premium) at a cost?

[5/28/10 3:08:33 PM] Peio Elissalde: Yes some Hydrographic Services (UKHO, CHS, AHS..) don't intend to display their charts publicly.

[5/28/10 3:09:04 PM] Peio Elissalde: So we provide a 'private' access via some monthly subscription. The reason is because Marine GeoGarage is required to royalty fee to display them online.

[5/28/10 3:09:19 PM] redwood.skinner: how does the 9.9 EUR/month fee stand up to competitors' offers?

[5/28/10 3:10:01 PM] Peio Elissalde: You mean comparatively to official WMS servers from the Hydrographic Services ?

[5/28/10 3:10:12 PM] redwood.skinner: for example.

[5/28/10 3:10:43 PM] Peio Elissalde: Do you know other web services ?

[5/28/10 3:11:03 PM] redwood.skinner: no.

[5/28/10 3:11:53 PM] Peio Elissalde: That's the reason why I haven't set this price comparatively to professional WMS access. The purpose is not the same.

[5/28/10 3:12:47 PM] Peio Elissalde: But as we are a pioneer in matter of nautical charts display online, difficult to imagine what is the real price of the market.

[5/28/10 3:13:07 PM] redwood.skinner: OK. you mentioned Cloud computing technology and then GeoGarage servers. Is the data "in the cloud" or on your servers? Can you help me understand this?

[5/28/10 3:15:07 PM] Peio Elissalde: That's exact there is some difference between classical client/server and Cloud Technology.

[5/28/10 3:15:58 PM] redwood.skinner: OK, but what about your service is in the cloud, so to speak?

[5/28/10 3:17:26 PM] Peio Elissalde: The Cloud computing part of the service provides some resources in back-end to ensure regular processes for updating the charts. And the ressources we use are dynamically scalable for accepting more chart data for example or future additional web services.

[5/28/10 3:18:34 PM] redwood.skinner: So it looks to me like you're laying HOs raster charts over a Google Earth presentation, and then allowing some manipulation. Is that it?

[5/28/10 3:18:40 PM] Peio Elissalde: What Marine GeoGarage changes is the concept of nautical electronic charts viewing:

you don't "own" anymore the charts, just "use" them and share them, anytime, anywhere you are via computer, mobile phone or any other Internet enabled personal device.

[5/28/10 3:18:56 PM] Peio Elissalde: Not Google Earth : Google Maps

[5/28/10 3:19:21 PM] redwood.skinner: Right. What kind of user numbers are you seeing so far?

[5/28/10 3:19:24 PM] Peio Elissalde: Google Earth is a stand-alone application, Google maps is the application accessible with some web browser.

[5/28/10 3:20:39 PM] Peio Elissalde: The web has just started at the beginning of March so 3 months old.

[5/28/10 3:21:25 PM] Peio Elissalde: But Marine GeoGarage is also the next step of our previous app : http://demo.geogarage.com/noaa

[5/28/10 3:21:52 PM] redwood.skinner: OK. And what kind of usership did you see from that app?

[5/28/10 3:22:07 PM] Peio Elissalde: Today we have between 500 and 1000 users which visits the website (mainly from the US because of the previous website)

[5/28/10 3:23:03 PM] redwood.skinner: what's the business plan, exactly? where does GeoGarage plan to make its revenue?

[5/28/10 3:23:07 PM] Peio Elissalde: We have not push a lot regarding communication for the marine press for the moment because we prefer to study the increasing of the charge.

[5/28/10 3:23:44 PM] Peio Elissalde: Marine GeoGarage uses a Freemium business model -mix of ad supported and subscription-, offering these Web services (described above) for free while charging a Chart Premium for accessing to certain nautical charts layers and certain privileges.

[5/28/10 3:24:29 PM] Peio Elissalde: The other wy to earn money is the Mobile side : we have just released the first iPad/iPhone application for New Zealand.

[5/28/10 3:25:22 PM] Peio Elissalde: In the future, we plan to add other web services such as tides, hight-resolution weather forecasts, vessel tracking...

[5/28/10 3:25:47 PM] redwood.skinner: Interesting. So you get a little mark-up from the fee-based charts. Would you prefer these charts go free (to increase usership) or prefer them stay on a royalty basis so you have that revenue stream?

[5/28/10 3:26:21 PM] Peio Elissalde: Personnally, I would prefer that all charts go to free.

[5/28/10 3:27:19 PM] Peio Elissalde: I guess this is a way among other to struggle against nautical maps piracy onboard, proposing up-to-date charts for the user.

[5/28/10 3:28:26 PM] redwood.skinner: how exactly does the machinery work? i mean, you have the google maps as API presumably, then how do you put the raster charts over them? Are you buying licenses, then hosting on own server and presenting? Or is the machine calling up the chart from (for example) NOAA as people access it through GeoGarage? How's this work?

[5/28/10 3:31:10 PM] Peio Elissalde: Actually, we have done some analysis about how Google stores and displays their charts in Google Maps. So we are using the same process to build some multi-resolution image pyramids (Tile Map Service)

[5/28/10 3:31:40 PM] redwood.skinner: ???

[5/28/10 3:31:42 PM] Peio Elissalde: Actually, our tile map server is composed of a static set of tiles, each one having a size of 256 pixels x 256 pixels. These small and regularly sized tiles form together on a screen a partial visual representation of some area at different levels of scale.

[5/28/10 3:33:32 PM] Peio Elissalde: Only the tiles needed to display the area currently on the screen are transported over the network.

The client/server communication is fast because the system is deterministic: all the tiles have been pre-generated so there is not any ‘on the fly’ calculation process such as in the WMS server (Web Map Service) which returns a section of a map based on the request with specified geographic coordinates.

All the tiles are prepared in advance for a fixed area in fixed zoom levels, so they are immediately available (no waiting as in the case of dynamically generated WMS requests).

[5/28/10 3:33:50 PM] Peio Elissalde: So the tiles are pre-generated instead of per-user way (WMS case).

[5/28/10 3:34:54 PM] redwood.skinner: would that mean that you are uploading the HO charts and updates onto your servers, then these are presented on the Google Maps infrastructure (as you say, pre-generated)?

[5/28/10 3:35:30 PM] Peio Elissalde: Yes exactly in the same way.

[5/28/10 3:35:59 PM] redwood.skinner: I guess there's no way you're going to do the same thing with vector charts?

[5/28/10 3:37:19 PM] Peio Elissalde: But today I'm not sure Google is rendering the tiles in a pre-generation way but certainly on the fly using cache on their big servers.

[5/28/10 3:37:38 PM] Peio Elissalde: You mean with ENC ?

[5/28/10 3:37:45 PM] redwood.skinner: Yes.

[5/28/10 3:39:00 PM] Peio Elissalde: Yes we have already done this with all the NOAA ENC but for technical reasons we are obliged to render the vector charts in raster.

[5/28/10 3:39:15 PM] redwood.skinner: files too large?

[5/28/10 3:40:16 PM] Peio Elissalde: The problem is that thz s-52 presentation norm (used in ECDIS) is not the best way for displaying charts on the web : http://blog.geogarage.com/2010/02/what-about-enc-and-marine-geogarage.html

[5/28/10 3:40:40 PM] Peio Elissalde: No this is only a problem of presentation.

[5/28/10 3:42:01 PM] redwood.skinner: OK. New question: You have deals with NOAA, UKHO, etc. What's preventing you from signing up with all the HOs from Oman to Croatia, Japan and Chile? Time and trouble? Contracting? Expense?

[5/28/10 3:42:07 PM] Peio Elissalde: The other issue is exceptly NOAA and UKHO all the other Hydrographic Services consider that the ENC data is only for ECDIS.

[5/28/10 3:43:01 PM] Peio Elissalde: So distributed by Primar in s-63 encryted format for registered ECS or ECDIS.

[5/28/10 3:43:20 PM] Peio Elissalde: Good question.

[5/28/10 3:43:44 PM] Peio Elissalde: Actually different situations :

[5/28/10 3:44:11 PM] Peio Elissalde: - some HS have not any georeferenced maps... So no way for us

[5/28/10 3:44:59 PM] Peio Elissalde: - some HS service have some entrance ticket too expensive for our small business

[5/28/10 3:45:46 PM] Peio Elissalde: - some HS service haven't study the possibility to distribute charts for web/mobile applications. So they need to study that on a legal form and a commercial form.

[5/28/10 3:46:50 PM] Peio Elissalde: - some Hydrographic Services have signed bilateral agreement (for example with UKHO) : so we are waiting for their agreement to get the raster charts corresponding to their geographical area but UKHO stamped

[5/28/10 3:47:24 PM] redwood.skinner: Have you gotten any interest from traditional chart suppliers, who might want to buy you and add you on to their own service portfolio? Or do they all just see you as competition?

[5/28/10 3:48:00 PM] Peio Elissalde: But we continue to push to get more charts (Australian charts will certainly be the next)

[5/28/10 3:48:59 PM] Peio Elissalde: To buy us ?

[5/28/10 3:49:57 PM] redwood.skinner: Yes, as a home/office route planning interface, for example. I'm thinking about industrial users here.

[5/28/10 3:50:49 PM] Peio Elissalde: No for the moment, we try to establish some links with companies involving selling charts on paper or CD

[5/28/10 3:51:54 PM] redwood.skinner: when did you guys start up with this whole business?

[5/28/10 3:52:21 PM] Peio Elissalde: Another idea (totally different) would be you use our nautical chart website (and its growing number of users) as a marketing tool to promote their charts.

The idea would be that a 'specific seller' layer is proposed to our users showing all your charts with a direct link to your website for purchasing CDs and paper charts.

(such as Amazon Associates Program)

So we could organize some Affiliate program in order we make money by advertizing 'specific seller' products :

- we advertise 'specific seller' products on our charts portal (viewing the charts online, the user exactly knows what he buys in CDs and paper charts from the 'specific seller')

- people follow the links to 'specific seller' website

- we earn up to xx% in referrals when our users concretely buy their products

[5/28/10 3:53:43 PM] redwood.skinner: OK. Like a shopping mall of sorts.

[5/28/10 3:54:55 PM] Peio Elissalde: Actually I worked since 1986 in Electronic Marine Navigation (I started in 1986 with MaxSea), then I develop with my associate Loic (an other former member of MaxSea) the first 3D seafloor mapping software in 1998.

[5/28/10 3:55:55 PM] Peio Elissalde: Actually our goal is to host all the nautical charts in the world (like Google Maps is doing for land maps and aerial/satellite imagery).

[5/28/10 3:57:05 PM] redwood.skinner: A single source of supply for all nautical chart needs (except ENC)? Something like that?

[5/28/10 3:57:49 PM] Peio Elissalde: Not supply but only viewing.

[5/28/10 3:58:23 PM] Peio Elissalde: I guess the vector data which is the future of e-navigation is also concerned.

[5/28/10 3:58:40 PM] redwood.skinner: Right, viewing, with immediate access to the supply.

[5/28/10 3:59:12 PM] redwood.skinner: I didn't understand the e-navigation statement. what did you mean?

[5/28/10 3:59:41 PM] Peio Elissalde: But Hydrographic Services must change their mind concerning the availability of ENC for web/mobile applications.

[5/28/10 4:00:27 PM] redwood.skinner: You mean it would be good to allow viewing of ENCs AND raster charts with the full functionality at Marine GeoGarage.

[5/28/10 4:00:57 PM] Peio Elissalde: I refer to the tem 'a la mode' of E-navigation http://www.imo.org/safety/mainframe.asp?topic_id=1369

[5/28/10 4:01:54 PM] redwood.skinner: yes, yes, it's a concept I'm familiar with, even if the whole thing's a bit mysterious

[5/28/10 4:02:04 PM] Peio Elissalde: Yes both ENC and raster, and in some years when the catalogue of charts will be full only ENC

[5/28/10 4:02:58 PM] redwood.skinner: OK, Peio. This has been good. I appreciate you taking the time. And I believe this may make an interesting post for the blog. I will also start following marine geogarage's blog. Interesting stuff for those interested in charts.

[5/28/10 4:03:15 PM] redwood.skinner: Have a nice weekend!

[5/28/10 4:03:25 PM] Peio Elissalde: Thanks.

Caves scuba diving with Wes Skiles

The blue holes of the Bahamas yield a scientific trove that may even shed light on life beyond Earth.
If only they weren’t so dangerous to explore.
Photograph by Wes C. Skiles

From National Geographic

Photographer Wes Skiles began to learn his craft in the most demanding environment on Earth: underwater caves.

As a teenager, camera in hand, he explored Florida's underwater labyrinths to capture images of this unphotographed realm.
He developed and refined the technique he became most known for: using multiple slaved strobes to dramatically illuminate and photograph this never-before-seen environment.

Later, as explorations led Skiles to remote locations around the world, he would strive to employ the latest technology, enhancing his ability to explore the environment and return with stunning images.
He's participated in caving and cave-diving expeditions in Mexico, Brazil, Puerto Rico, and Australia.

As an expedition cameraman, Skiles specializes in capturing images of people and wildlife on the edge of extreme frontiers.
His visual imagery provides the viewer with an intimate understanding and unique perspective of his subjects.

Skiles works on assignment as a freelance photographer for National Geographic magazine.
His work has also been featured in Outside and numerous diving publications.
Skiles is equally skilled in the art of telling stories though moving pictures.
He has produced, directed, and filmed over a hundred television films, many of which have won international awards and acclaim.

Links :

• FastCompany : (Really) Risky Business
• Blue Holes project
• YouTube : Mexico cave diving Jailhouse
  

Navy subs help scientists expand study of Arctic thaw

From NYTimes

Scientists who study the Arctic's icy cap now have a new weapon at their disposal -- nuclear-powered Navy submarines.

Civilian researchers have signed an agreement with the Navy to revive a dormant program that uses the vessels to collect information on parts of the Arctic's ice and ocean that normally lie beyond scientists' reach.

Called SCICEX -- short for "Science Ice Exercise" -- the program began in 1993 when the USS Pargo carried five civilian scientists to the Arctic on a test cruise.

But after six years and five additional dedicated science cruises to the far north, project SCICEX sputtered.

"When the Cold War ended, the Department of Defense really turned its attention to lower latitudes," said Jackie Richter-Menge, a sea ice expert at the Army Corps of Engineers' Cold Regions Research and Engineering Laboratory in Hanover, N.H. "There wasn't really the support to continue that level of support to the scientific community."

Instead of providing submarines for planned science missions to the Arctic, the Navy conducted four "scientific accommodation missions" between 2000 and 2005 -- collecting information during brief pauses in classified submarine exercises.

For the last five years, the submarines -- part of a force stretched thin by conflicts in Afghanistan and Iraq -- have not gathered any data. At the same time, the Arctic has seen dramatic warming that led to a historic low in summer sea ice in 2007, when its areal cover dropped roughly 40 percent below the 30-year average. Scientists have also documented shortening of the region's snow season, rising land surface temperatures and warmer permafrost, and changes in the population and habitat of polar bears, walruses, seabirds and other Arctic wildlife.

A deeper look at a transforming region

Now, with the Arctic's transformation in mind, scientists and the Navy are collaborating to restart the SCICEX program -- with constraints.

Richter-Menge heads a scientific advisory committee that just released a detailed wish list for Arctic data, ranging from measurements of "ice draft" -- how much of the region's sea ice cover lies submerged below the ocean's surface -- to measurements of ocean chemistry, maps of the ocean floor and information on marine microbes.

The idea is to provide a prioritized list for the Navy, which will collect data as time allows on otherwise classified submarine missions. Security concerns prevent advance planning of science activities aboard the subs.

"The goal was to carve out some small amount of time on those planned missions," Richter-Menge said. "There was a general understanding, both from the military standpoint and the scientific standpoint, that you still have to understand the environment."

Reviving the SCICEX effort fits in the with Navy's renewed interest in the Arctic. The region's continuing thaw has positioned the region as a potential future hotbed of tourism, shipping, energy and mineral exploration -- and an emerging military frontier.

With scientists predicting Arctic summers could be ice-free by the 2030s, the ensuing resource grab could increase the potential for competition and conflict between nations, the Navy's Task Force Climate Change warned in its Arctic strategy, released last fall.

'Ground truth' for the satellites

"We really want to understand when changes will be significant enough to provide for increasing access to shipping, resource exploitation and future increased engagement in that region," said Capt. Tim Gallaudet, the task force's deputy director.

In the Arctic, "the players are a little more dynamic now," he saaid. "We're seeing non-Arctic players now. China has an ice-strengthened research vessel."

For scientists, the advantage of SCICEX lies in harnessing submarines that can travel at high speed and operate even in areas that are covered by ice -- missions that would otherwise require use of icebreaking ships, which are in short supply.

And though satellites can cover more ground and easily document multiple snapshots in time, Richter-Menge said the submarine data would be invaluable to help "ground-truth" measurements collected high in the sky.

"The submarine has the advantage of looking up at the ice from underneath," she said, "When they take an ice draft measurement, they're measuring nine-tenths of the ice cover, and they're more accurate."

Exploring the missing nine-tenths

With satellite measurements, scientists must apply a mathematical formula to convert the portion of sea ice that sits above the water line -- roughly one-tenth of total ice volume -- to determine how much ice bobs in the Arctic Ocean.

The submarines can also collect data on ocean chemistry that satellites cannot.

"What it does is gives us a great validation point for [computer] models that are being built to make sea ice forecasts," Richter-Menge said. "Those models, our ability to do that, are important for a variety of reasons: global climate change, the role that sea ice plays in the climate, the whole issue of operations with ships traversing the Arctic, be that for tourists or trade or anything like that."

The renewed SCICEX program will operate under a memorandum of understanding inked in 2000 between the National Science Foundation and parts of the Navy.

The new science plan calls for collection of baseline data on the Arctic's ice canopy and seafloor and the physical, chemical and biological properties of Arctic seawater.

Navy technicians will gather the data using instruments already installed on the submarines during direct transits across the Arctic Basin, from the Atlantic to the Pacific or vice versa. The submarines will also have an opportunity to collect data during biennial exercises in the southern Beaufort Sea, called ICEX, for which the Navy establishes an ice camp.

Scientists to create the most detailed map of California coastline ever assembled

Santa Clarita, California (courtesy of Airborne1)

From MercuryNews

Their tools are laser beams, airplanes and computer software — instead of compasses, wooden ships and parchment.

But more than 400 years after explorers like Sir Francis Drake and Sebastian Vizcaino made some of the first maps of California's spectacular coastline, state and federal scientists are embarking on a new project to construct the most detailed map of the California coast ever assembled.

The $3.3 million effort will begin with researchers in an airplane flying back and forth along the coast shooting thousands of laser pulses per second at the rocks, beaches and cliffs along the 1,200-mile shoreline from Mexico to Oregon, generating ultra-detailed 3-D images of the contours of the land in huge computer files.

"We need a better sense of what's out there. We need a modern map. And with a modern map we'll have the knowledge to make better decisions," said Doug George, a project manager with the Ocean Protection Council, a state agency in Oakland that approved $2.75 million toward the project last month.

The images will be so sharp the map should be able to discern individual boulders and telephone poles, George said. The data will provide a baseline to measure everything from the impact of rising oceans over the coming decades, to beach erosion, to flooding risks from large winter storms.

The mapping work, supervised by the National Oceanic and Atmospheric Administration, will start next month and is expected to conclude by December, with the images posted to the Internet by next summer.

Starting point needed

Over the decades, there have been many detailed photo sets and maps produced of sections of the coast. But there isn't a single, high-resolution topographical map of the complete California shoreline generated at the same time using uniform standards.

"The baseline is a critical piece. You can't monitor anything if you don't have a good starting point — and we don't have a good starting point," said Sam Johnson, a research geologist working on the project with the U.S. Geological Survey in Santa Cruz.

Apart from studying erosion and sea level rise, the images also will be used by agencies such as the California Coastal Commission, state parks, or cities to plan wetland restoration, floodplain management, storm water management, better public access to beaches and coastal development.

Every few years, heavy storms cause cliffs to erode in places like Pacifia, Capitola and Goleta. Beaches in San Diego and Orange County wash away. Better information could help prioritize projects in those places, supporters of the map effort say.

"California's coast has gone through some dramatic changes over the last 150 years. Beaches erode and grow, bluffs collapse," said Johnson. "Every place is different. You might lose 20 meters of beach over 50 years, or it might happen all at once."

The high-tech tools used in the mapping may have generated your last speeding ticket.
Known as Light Detecting and Ranging, or LiDAR, the technology is similar to what police use to nab speeders. Researchers shoot harmless pulses of light from the aircraft, and images are generated by computing the amount of time it takes a pulse to leave the plane, travel to the ground and return to sensors.

Each data point has a longitude, latitude and elevation. And where many satellite maps might have one data point every 100 feet, LiDAR images can provide one data point every 3 feet or less.

Ocean floor to land

In addition to the coast, the project will also take images of San Francisco Bay.
"This is absolutely cool. I have a picture on my wall of a 1770s map of San Francisco Bay. It looks like the results of a lower digestive tract x-ray," said Will Travis, executive director of the Bay Conservation and Development Commission, a state agency that regulates development around the bay.

"But from the perspective they had, without aerial photography, it was very reasonable. You look at that next to a USGS map, and you see how much more precise and realistic it is. This is taking it to the next generation."

The ocean already has risen 8 inches over the past 100 years, as measured by tidal gauges at Fort Point in San Francisco. Computer models run by the Scripps Institution of Oceanography, the U.S. Geological Survey and other research centers predict at the current rate of global warming, sea level could rise another 55 inches — or nearly five feet — by the end of this century as ice sheets continue to melt and the warmer ocean water expands.

The infrared laser beams don't penetrate water well. So researchers hope to combine all the images from land, which will extend inland from the water to about 30 feet in elevation, with other sets of sonar images of the ocean floor that USGS, NOAA and Cal State Monterey Bay have been collecting from boats since 2005.

"Our goal is to have a seamless map of the land and sea," said George. "That's the holy grail everyone is looking for to help with research on sea level rise, tsunamis, all kinds of work."
Findings could be used to figure out where to build sea walls, or expand wetlands to reduce flooding, or where to move existing development.

"The next step we want to do is an assessment of vulnerability of various resources to sea level rise — airport runways, Silicon Valley, the Embarcadero in San Francisco, Treasure Island," said Travis. "And you can't do that unless you know the exact height of everything."

Links :

• California Seafloor Mapping Program (CSMP)
• OpenTopography