‘Black hole’

 

 

25 March 2011
Holbox Island and the Yalahau Lagoon on the northeast corner of Mexico’s Yucatan Peninsula are featured in this satellite image.

Holbox is a 42-km-long island running along the peninsula’s coast that is separated from the mainland by Yalahau Lagoon. One of the world’s most important ecosystems, Holbox and its surrounding waters are part of the Yum Balam Biosphere Reserve.
Its unspoiled beaches of fine white coralline sands are important for turtle nesting, and over 500 bird species can be found here.
Caboe Catoche, the cape at the eastern tip of the island (right), is where the Gulf of Mexico and the Caribbean Sea meet. Their mingling waters create a kaleidoscope of turquoise and emerald hues.
Located where the currents of the Gulf, Caribbean and the Atlantic Ocean mix to create nutrient-rich waters, this area supports an abundant and diverse array of marine life.
In addition to dolphins, manta rays and several shark species, the plankton-rich waters support the world’s largest known congregation of whale sharks – our planet’s largest fish – for five months of the year.
The freshwater lagoon has a deep rocky hole that surrounds the island, making the water appear black. It is thought that Holbox, which in Mayan translates as ‘black hole’, was named after the dark lagoon water.
The Korea Multi-purpose Satellite (Kompsat-2) of the Korea Aerospace Research Institute acquired this image on 12 March. Launched in 2006, it was developed to ensure continuity with its predecessor, Kompsat-1.
ESA supports the Kompsat series as a Third Party Mission, meaning it uses its ground infrastructure and expertise to acquire, process and distribute data to users. 

Source:ESA

ArcGIS Viewer for Microsoft Silverlight Now Available

Esri's new ArcGIS Viewer for Microsoft Silverlight can now be downloaded at no cost from the Esri Beta Community site. The viewer is a ready-to-use, configurable web mapping application built on ArcGIS API for Silverlight/WPF.

Users can easily configure ArcGIS Viewer for Microsoft Silverlight without writing a single line of code or editing configuration files. The download includes an application builder tool for making and previewing changes to the viewer data content, tools, and layout. The viewer is designed so that users can customize the look and feel of applications, add and configure tools, and extend the viewer framework with custom add-ins.

ArcGIS Viewer for Microsoft Silverlight supports existing business workflows that require mapping visualization, editing, and analysis. It also simplifies access to ArcGIS Online and ArcGIS Server services and accelerates web mapping application deployment.

Developers can create custom add-ins, which are modular units of code for extending the viewer with new capabilities. The common Silverlight/WPF API framework allows custom add-ins to be used with ArcGIS Mapping for SharePoint.

Internet: www.esri.com

Mapping Japan's changed landscape from space

Following the massive earthquake and tsunami that hit Japan on 11 March, satellite imagery has been vital in providing a clear picture of the extent of devastation to aid the relief effort now underway.

In response to this event, which turned out to be the biggest earthquake Japan has suffered in living memory, the International Charter 'Space and Major Disasters' was triggered by the Cabinet Office of Japan the same day the earthquake struck. As a result, satellite images from several space agencies and operators from around the world are being used to map and assess the stricken areas.
Founded 10 years ago, the International Charter is a unique mechanism to ensure that timely satellite images are made freely available to authorities and aid workers coping with the aftermath of a disaster.
By combining Earth observation data from different space agencies, the Charter allows resources and expertise from around the world to be coordinated for rapid response to major disasters.  
 

Download:

HI-RES JPEG (Size: 1291 kb)

The value of the initiative lies in the way it has been set up to gather and coordinate a range of different satellite data, turn them into usable products and provide a single access point to the products 24 hours a day, 7 days a week, and at no cost to the user.
Demonstrating the incredible power that Earth can unleash, the devastation caused by the 8.9-magnitude quake has left the world stunned.
Japan's northwestern coastline is thought to have shifted by as much as 4 m to the east and whole towns have been washed away by the tsunami, completely changing the landscape.
Satellite maps are providing essential information for search and rescue teams on the ground and for damage assessment. Before-and-after images show how the land has changed and where buildings and roads once stood.
  Work is being coordinated by the Japan Aerospace Exploration Agency, JAXA, and the Asian Institute of Technology. Data are being used from a wide range of satellites such as Germany’s TerraSAR-X and RapidEye, France’s SPOT-5 and ESA's Envisat along with high-resolution optical imagery from US satellites. Over 63 satellite acquisitions were made in the first 48 hours following the event. These are being used by relief teams and decision-makers responding to the disaster.
A large collaboration is at work to exploit data offering value-adding analysis with specialist centres from France (Sertit), Germany (DLR-ZKI) and the United Nations (UNITAR/UNOSAT), while JAXA provide dedicated mapping service to the Japanese authorities.
 

Download:

HI-RES JPEG (Size: 1969 kb)

Over the coming weeks, access to updated satellite products will prove essential for continued crisis response and also to start precise damage assessment for recovery, rehabilitation and reconstruction.
Satellite data will also be used to help further our understanding of these geological threats and ultimately help with future warning systems.
Japan lies on the infamous Ring of Fire, an active zone that almost encircles the Pacific Rim. As such, Japan is listed as a 'supersite', an area known to be at high risk of seismic events.
The Geo-Hazard Supersites initiative, coordinated by the Group on Earth Observations, is exploiting 20 years of satellite radar observations to further our understanding of geological risk.
The aim is to exploit interferometric processing to provide very precise terrain deformation mapping before and during a seismic event to improve our understanding of the tectonic phenomena in Japan.
As another example of different space agencies working together, the initiative promotes research into geohazards by providing the worldwide scientific community with easy access to a full spectrum of datasets.
source: ESA

Earthquake and Tsunami near Sendai, Japan

download large image (398 KB, JPEG) acquired March 11, 2011

On March 11, 2011, at 2:46 p.m. local time (05:46 Universal Time, or UTC), a magnitude 8.9 earthquake struck off the east coast of Japan, at 38.3 degrees North latitude and 142.4 degrees East longitude. The epicenter was 130 kilometers (80 miles) east of Sendai, and 373 kilometers (231 miles) northeast of Tokyo. If initial measurements are confirmed, it will be the world’s fifth largest earthquake since 1900 and the worst in Japan’s history.
This map shows the location of the March 11 earthquake, as well as the foreshocks (dotted lines) and aftershocks (solid lines). The size of each circle represents the magnitude of the associated quake or shock. The map also includes land elevation data from NASA’s Shuttle Radar Topography Mission and ocean bathymetry data from the British Oceanographic Data Center.
According to the U.S. Geological Survey (USGS), the earthquake occurred at a depth of 24.4 kilometers (15.2 miles) beneath the seafloor. The March 11 earthquake was preceded by a series of large foreshocks on March 9, including an M7.2 event. USGS reported that the earthquakes “occurred as a result of thrust faulting on or near the subduction zone interface plate boundary.”
The March 11 quake sent tsunami waves rushing into the coast of Japan and rippling out across the entire Pacific basin. Crescent-shaped coasts and harbors, such as those near Sendai, can play a role in focusing the waves as they approach the shore. Also, since land elevation is low and flat along much of the Japanese coast, many areas are particularly vulnerable to tsunamis.
The Japan Meteorological Agency reported maximum tsunami heights of 4.1 meters at Kamaishi at 3:21 p.m. (06:21 UTC), 7.3 meters at 3:50 p.m. (06:50 UTC) at Soma, and 4.2 meters at 4:52 p.m. (07:52 UTC) at Oarai.
The U.S. Pacific Tsunami Warning Center (PTWC) reported a wave with maximum height of 2.79 meters (9.2 feet) at an observing station at Hanasaki, Hokkaido, at 3:57 p.m. local time (06:57 UTC). Other PTWC reports:

• 1.27 meters (4.2 feet) at 10:48 UTC at Midway Island
• 1.74 meters (5.7 feet) at 13:72 UTC at Kahului, Maui, Hawaii
• 1.41 meters (4.6 feet) at 14:09 UTC at Hilo, Hawaii
• 0.69 meters (2.3 feet) at 15:42 UTC in Vanuatu
• 1.88 meters (6.2 feet) at 16:54 UTC at Port San Luis, California
• 2.02 meters (6.6 feet) at 16:57 UTC at Crescent City, California

1. References

2. Japan Meteorological Agency (2011, March 11). Latest Tsunami Information. Accessed March 11, 2011.
3. Pacific Tsunami Warning Center (2011, March 11). Tsunami Messages for the Pacific Ocean. Accessed March 11, 2011.
4. U.S. Geological Survey (2011, March 11). Magnitude 8.9 - Near The East Coast of Honshu, Japan. Accessed March 11, 2011.

NASA Earth Observatory image created by Robert Simmon and Jesse Allen, using earthquake and plate tectonics data from the USGS Earthquake Hazard Program, land elevation data from the Shuttle Radar Topography Mission (SRTM) provided by the University of Maryland’s Global Land Cover Facility, and ocean bathymetry data from the British Oceanographic Data Center’s Global Bathmetric Chart of the Oceans (GEBCO). Caption by Michael Carlowicz.

Instrument: Seismograph

Source: nasa.gov

Flooding from Tsunami near Sendai, Japan

download large image (9 MB, JPEG) acquired March 12, 2011

download large image (15 MB, JPEG) acquired February 26, 2011

NASA’s Terra satellite’s first view of northeastern Japan in the wake of a devastating earthquake and tsunami reveal extensive flooding along the coast. The Moderate Resolution Imaging Spectroradiometer (MODIS) acquired the top image of the Sendai region on March 12, 2011, at 10:30 a.m. The lower image, taken by Terra MODIS on February 26, 2011, is provided as a point of reference.
Water is black or dark blue in these images. It is difficult to see the coastline in the March 12 image, but a thin green line outlines the shore. This green line is higher-elevation land that is above water, presumably preventing the flood of water from returning to the sea. The flood indicator on the lower image illustrates how far inland the flood extends.
Both images were made with infrared and visible light, a combination that increases the contrast between muddy water and land. Plant-covered land is green, while snow-covered land is pale blue. Clouds are white and pale blue. The paved surfaces in the city of Sendai colors it brown.
MODIS detected a fire burning near the shore north of Sendai. The fire is marked with a red box. It is also surrounded by floods.
The photo-like true-color image acquired a few hours later shows plumes of sediment washed into the ocean along the coast and a dark plume of smoke near Sendai. Both images are from the MODIS Rapid Response System, which provides twice-daily images of Japan.

NASA images courtesy the MODIS Rapid Response Team at NASA GSFC. Caption by Holli Riebeek.

Instrument: Terra - MODIS

Dust Travels from Iraq to Iran

download large image (4 MB, JPEG) acquired March 3, 2011

download large image (4 MB, JPEG) acquired March 4, 2011

Sandy deserts, impermanent lakes, and riverbed sediments provide plentiful material for dust storms in Iraq. The dust often blows toward the southeast, spreading into Iran or traveling over the Persian Gulf. In early March 2011, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured the progression of one such storm.
The top image, from March 3, 2011, shows the storm in its early stages as dust rises from discrete points along the Iraq-Syria border. Spanning more than 100 kilometers, the plume is thick enough to completely hide the land surface below. The dust stops short of Baghdad, however, and skies southeast of the city are clear.
The bottom image shows the dust storm on March 4, 2011 after the dust has traveled toward the east-southeast. On this day, skies are clear northwest of Baghdad. A thick plume of dust, however, hovers over the Iraq-Iran border, and obscures the coastline of the Persian Gulf. Dust also fills the skies over Kuwait.
Dust storms are common in Iraq, and frequently spread to neighboring countries, including Saudi Arabia and Iran.

NASA images courtesy MODIS Rapid Response Team at NASA GSFC. Caption by Michon Scott.

Instrument: Aqua - MODIS

Source: nasa.gov

NZ quake mapped from space

 

The coloured bands, or fringes, represent movement towards or away from the spacecraft

The upheaval wrought by the 22 February earthquake in Christchurch, NZ, is illustrated in new radar imagery.

The Magnitude 6.3 tremor killed more than 160 people and shattered a city already reeling from a previous seismic event in September.
Data from the Japanese Alos spacecraft has been used to map the way the ground deformed during the most recent quake.
It shows clearly that the focus of the tremor was right under the city's south-eastern suburbs.
The type of image displayed on this page is known as a synthetic aperture radar interferogram.

It is made by combining a sequence of radar images acquired by an orbiting satellite "before" and "after" a quake.

The technique allows very precise measurements to be made of any ground displacement that takes place between the image acquisitions.
The coloured bands, or fringes, represent movement towards or away from the spacecraft.
In this interferogram, the peak ground motion is almost 50cm of motion towards the satellite.
"It's like a contour map but it's showing to the south-east of Christchurch that the ground motion is towards Alos. That's uplift," explained Dr John Elliott from the Centre for the Observation and Modelling of Earthquakes and Tectonics (Comet) at Oxford University, UK.
"And then right under Christchurch, we see subsidence. That's partly due to liquefaction but it's mainly due to the way the Earth deforms when you snap it like an elastic band."
Where the rainbow fringes become most tightly spaced is where the fault break came closest to the surface, although the data indicates the fault is unlikely to have broken right through to the surface.
Blind danger Liquefaction is a phenomenon that afflicts loose sediments in an earthquake and is akin to a lateral landslide.
It is a major issue for Christchurch because the city is built on an alluvial plain, and this type of ground will amplify any shaking during a tremor.

 

BBC News reader Gillian Needham took this image of central Christchurch moments after the quake struck New Zealand's second city on 22 February

Scientists are using the Alos information to understand better the future seismic hazards in this part of New Zealand.
It has become obvious from recent events that Christchurch sits close to "blind" faulting - faulting that is at risk of rupture, but which betrays little evidence of its existence at the surface, meaning the potential danger it poses is not fully recognised.
"It means much more work needs to be done around Christchurch," said Dr Elliot.
"People knew they could get earthquakes further into the mountains [in the west of South Island]; that's how they've been built in some ways, through earthquakes and all the faulting.
"But to get an earthquake right under their city will have been a surprise to nearly every single person."
Liquid lurch The interferogram is noticeably incomplete - there are several areas where the fringing is missing. There are a number of reasons for this.
To the east is ocean, and this technique does not work over water.
To the west, the issue is related to the satellite track and the fact that it views the Earth in strips. Hence, you get bands of data.
But the more interesting and more relevant omissions are in Christchurch itself.
Dr Elliot commented: "Here, the patches are the result of de-correlation between the acquisition images, where we just can't match them - they're too different.
"There are a few reasons for that. Usually it's the result of vegetation growth, but here it could be due to more extreme shaking or liquefaction."

 

Tuesday's quake was less energetic but more destructive

Researchers are investigating the relationship between September's Magnitude 7.1 quake and last month's 6.3 event.
The latter is very much considered to be an aftershock from the former, even though they were separated by six months.
The September quake occurred about 40km to the west, rupturing a similar length of fault. The most recent tremor ruptured about 15km of fault.
What scientists need to know now is the nature of any "seismic gap" between the two; that is, a segment of fault which was not broken in either tremor but which may have been loaded with additional strain because of both those events.

 

The Advanced Land Observing Satellite (Alos) was launched in 2006

 

Source: http://www.bbc.co.uk 

NAVTEQ services now for Hyundai and Nissan

Geneva, US: During Geneva Motor Show, NAVTEQ announced that it has been chosen by Hyundai to provide advanced content for its new navigation platform which features a green routing option as well as the traditional 'shortest' or 'fastest' routes. In addition, the company also announced that it has been chosen by Nissan to provide location content for 100% Electric Nissan LEAF points of interest (POIs), specifically developed to guide and inform Electric Vehicle (EV) drivers

NAVTEQ & Hyundai
Hyundai developed the new software using NAVTEQ's digital map data with additional ADAS attributes such as slopes, height and curvature which enable the routing calculations to take into account more precise road geometry and the nature of the terrain. This has been coupled with NAVTEQ Traffic Patterns which predicts where and when traffic jams will happen based on when they typically occur - so drivers can be guided via alternative routes where traffic flows more smoothly. Together these attributes enable the navigation system to find routes which minimise fuel consumption.

"It is rare for this type of 'green routing' option to be available in C–segment vehicles but we are looking to exploit any opportunity which encourages responsible driving and lowers CO2 emissions," commented Allan Rushforth, COO & SVP European Operations, Hyundai Motor Europe GmbH.

NAVTEQ & Nissan
With first deliveries in Europe due in the first quarter of 2011, the Nissan LEAF includes the Nissan Connect powered by CARWINGS navigation system as standard so drivers will be able to benefit from the EV dedicated NAVTEQ POIs which contain key information for Nissan LEAF owners.

Tom Smith, Nissan LEAF Chief Marketing Manager, Nissan International Sam, said, "Ability to 'read the road ahead', relies on an accurate, precise map. NAVTEQ's unique approach to quality is key to the value of this offering as it helps give drivers the confidence they need when they drive to find EV charging stations."

Source: NAVTEQ – Link1 & Link2

Esri Releases ArcGIS API for JavaScript 2.2

Just in time for the Esri Developer Summit, Esri has pushed out the ArcGIS API for JavaScript.  Esri says it includes “many oft-requested features that will improve the usability of the Web apps you build”. 

Sharks navigate using 'mental maps'

Tiger sharks can navigate on scales of many kilometres - perhaps aided by internal maps.
 

Some shark species make "mental maps" of their home ranges, allowing them to pin-point destinations up to 50km (30 miles) away, research suggests.

US-based scientists analysed data from tiger sharks tagged with acoustic transmitters, and found that they took directed paths from place to place.
Other species such as blacktip reef sharks did not show this behaviour.
Writing in the Journal of Animal Ecology, researchers suggest this shows a capacity to store maps of key sites.
In addition, it is further evidence that the great fish can navigate, possibly using the Earth's magnetic field.
Earlier research in Hawaii had shown tiger sharks swimming across deep channels and finding shallow banks rich in food 50km away.
In this project, researchers used statistical techniques to show the journeys were not made by accident; the sharks were following some kind of path.
Blacktips, however, did not. A third species, thresher sharks, also showed "directed walking" like the tigers, but on much smaller scales.
"Our research shows that, at times, tiger sharks and thresher sharks don't swim randomly but swim to specific locations," said research leader Yannis Papastamatiou from the Florida Museum of Natural History in Gainesville.
"Simply put, they know where they are going."
Maps and magnets A key question is how they know where they are going.
Sharks are among the wide array of animals that can sense magnetic fields.

Thresher sharks proved less able navigators

But whereas others, such as yellowfin tuna, apparently do this using small amounts of the mineral magnetite in their heads, sharks do not appear to maintain deposits of this magnetic sensor.
Alternative possibilities are that they use signals from ocean currents, water temperature or smell.
"They have to have a pretty good navigation system because the distances are great," Dr Papastamatiou told BBC News.
"Which one it is is open to debate, but the fact that many of these journeys took place at night - you and I would think there's nothing to orientate to, so orientating to magnetic fields is one possibility."
Among thresher sharks, adults made much longer directed journeys than juveniles.
The researchers say this suggests the fish build up mental maps as they mature.
The differences between species are probably explained by the varying ways in which they live.
Blacktip reef sharks (Carcharhinus melanopterus), although widespread around the Pacific, appear to have small ranges within their home reef system.
On the other hand, tiger sharks (Galeocerdo cuvier) can cover huge distances. Tags have been recovered from individuals more than 3,000km away from where they were attached.
source: http://www.bbc.co.uk