Wednesday, April 30, 2008

UN Chief: Food Crisis Is Now Emergency

UNITED NATIONS (AP) -- A rapidly escalating global food crisis has reached emergency proportions and threatens to wipe out seven years of progress in the fight against poverty, Secretary-General Ban Ki-moon warned Monday.
He called for short-term emergency measures in many regions to meet urgent food needs and avoid starvation and longer-term efforts to significantly increase production of food grains.

The "international community will also need to take urgent and concerted action in order to avoid the larger political and security implications of this growing crisis," Ban told international finance and trade officials who came to a U.N. meeting following weekend talks in Washington.

The "international community will also need to take urgent and concerted action in order to avoid the larger political and security implications of this growing crisis," Ban told international finance and trade officials who came to a U.N. meeting following weekend talks in Washington.

The secretary-general echoed World Bank President Robert Zoellick's appeal to governments on Sunday to quickly provide the U.N. World Food Program with $500 million in emergency aid that it needs by May 1.

Zoellick said the international community has "to put our money where our mouth is" to deal with rapidly rising food prices that have caused hunger and deadly violence in several countries.

Ban said the recent steep rise in food prices "has already raised the cost of WFP's needs to maintain its current operations from $500 million to $755 million."

WFP, the world's largest humanitarian agency, issued an "extraordinary emergency appeal" to donor countries for $500 million last month, saying the money was needed by May 1 to avoid cutting rations to some of the world's most impoverished regions. The Rome-based agency said its funding gap was growing weekly.

"The rapidly escalating crisis of food availability around the world has reached emergency proportions," Ban said.

"The World Bank has estimated that the doubling of food prices over the last three years could push 100 million people in low income countries deeper into poverty," he said.

Ban echoed Zoellick in warning that that the food crisis "could mean seven lost years in the fight against worldwide poverty."

The United Nations is at a midpoint in its campaign to reduce global poverty and improve living standards of the world's bottom billion. The Millennium Development Goals, adopted at a U.N. summit in 2000, include cutting extreme poverty by half by 2015.


UN to tackle food crisis this week

United Nations Secretary General Ban Ki-moon has announced a concerted effort by 27 key UN agencies to tackle the growing crisis in the sharp rise in basic food prices.

The UN has warned that sharp rises in cereal prices have left 37 poor countries in an emergency situation, sparking food riots.

A committee is scheduled on Monday to tackle the problem at a two-day conference in the Swiss capital Bern.

The conference will explore long-term measures to solve the world's food crisis, including adjudicating between advocates of protectionism and those who favour opening up markets.

Rising populations, strong demand from developing countries, increased cultivation of crops for biofuels and increasing floods and droughts have sent food prices soaring across the globe.

Results of the deliberations are expected Tuesday when Ban Ki-moon gives a press conference.

Tuesday, April 29, 2008

Satellite-Derived Yield Forecasts for Wheat, Corn, Soybean and Other Crops

Using satellite imagery to measure plant biomass, a team of crop scientists has demonstrated an ability to forecast yields of various crops much sooner than traditional methods, and with considerable accuracy, announced Planalytics, Inc. as they introduced their new GreenReport E-newsletter.
"Since 1999, Planalytics and our strategic partner TerraMetrics Agriculture, Inc. (TMAI) have used satellite imagery to track and measure vegetative growth conditions across the U.S.", said Jed Lafferty, Managing Director of Planalytics Life Sciences. "The satellite images estimate the amount of chlorophyll that growing plants are producing", he continued. "By combining these 'Greenness' maps with our weather intelligence to create Planalytics GreenReport, we can provide our clients with more timely and actionable information than they get with just the drought monitor or soil moisture reports."
Recently, however, research conducted as part of the Greenness initiative has surfaced that adds considerable value to the plant biomass maps that Planalytics business meteorologists have been using for years. According to Lafferty, a team of crop scientists affiliated with TMAI and the Kansas Applied Remote Sensing program (KARS) at the University of Kansas have compiled six years of nationwide crop yield forecast results for wheat (winter, spring and durum), corn, soybeans, oats, barley and sorghum. The first winter wheat forecast for 2008 was produced on March 21st. "By using satellite imagery instead of traditional sampling techniques, crop yield forecasts can be generated up to two months before USDA estimates. And because they are based on images that are constantly being downloaded from the satellite, we can update these forecasts every two weeks throughout the growing season."
Lafferty goes on to add that, compared to initial USDA forecasts or normalized trends, the TMAI/KARS forecast models have been shown to be consistently more accurate in recent years. "It is hard to say whether it is the methodology that's used or the volatility of recent years' weather events, but these bi-weekly crop forecasts appear to answer many of the questions that our clients involved in grain trade have been struggling with."
Planalytics GreenReport and Crop Yield Forecasts are available through subscription only. For more information, go to

Source :

GIS and Satellite Remote Sensing for Arachaeology

Satellite remote sensing can provide a variety of useful data for this type of research. A variety of sources for such data exist, and while the data can be expensive and require extensive digital image processing, they provide a synoptic view which is not available from aerial photography. It takes over 200 aerial mapping photos to cover the same area as a single satellite image. We have used a variety of satellite data for this project, including older Landsat MSS from the late 1970's and more modern French SPOT and Radarsat data. New systems with 1 meter spatial resolution are now commercially available, but have not been used in this project due to cost (donations are welcome!).

The image at right is a SPOT image overlaid on a digital elevation model of the area.

Landsat Multi Spectral Scanner (MSS)

Early in the project the only available remote sensing data was Landsat MSS, with 80 meter spatial resolution. Two images were acquired and digital image processing was conducted to generate color composite images and vegetation maps.

The following images are from the 22 March, 1973 image of the region shown in false color infrared.

This first image shows the entire study area, with the pasture lands shown in pink, forest in darker reds, urban in gray, and water in black.

The image at right show the northern part of the study area. Al left you see the southern part of the research area. The banding is an artifiact of the data, and was later removed using digital image processing techniques. You can clearly see the river and gravel mines along it.

French SPOT Data

The commercial civil remote sensing system developed by the French is called SPOT. It has a spatial resolution of 20 meters for multi-spectral data, which records information in three bands of the spectrum, and a 10 meter spatial resolution for a panchromatic band. The resolution of these images available from space can provide significant improvements in the utility of these data for regional archaeological and environmental applications, especially (as in France) where the field size is very small. Accurate modern landcover maps can be produced using SPOT satellite imagery. Below is a SPOT image which has been classified into a landuse/landcover map of the area. Yellows are pasture, greens are forest, blues are water, and reds are urban. This image was then combined with a shaded relief map (derived from a Digital Elevation Model) to produce a realistic representation of the landscape.

This is a SPOT land use/landcover image draped over the Digital Elevation Model from the project GIS database. Click on the image to see the larger version. You can clearly see the river valley down the center of the image, and the Morvan mountains at the top. The confluence of the Arroux and the Loire is at the bottom of the image. The red line at bottom is the modern highway from the town of Digoin at the confluence of the rivers, and Paray-le-Monial at right. The larger blue areas along the river are the lakes that the gravel mines leave after they remove the materials.


This is a color infrared SPOT 20 meter image, acquired 9 Nov. 1986, showing Mt. Beuvray, site of the ancient city of Bibracte, at upper left. The Arroux river valley flows from top to bottom on the right side. The city of Autun, ancient Augustodunum Aedorum, is at top right.

A close-up view of Mt. Beuvray, 9 Nov. 1986.

SPOT Satellite landcover map-modern vegetation

RADARSAT imagery

Canadian RADARSAT-1 satellite imagery has been acquired of the region on 4 November, 1998 with a spatial resolution of 8 meters. This system is different from SPOT or Landsat in that it is an active radar system that sends its own burst of electromagnetic radiation down to the ground which is then bounced off the surface and recorded on the satellite. Analysis of the Radarsat is ongoing. This system can operate day or night and through cloud cover. It provides a different and new way of visualizing the area. This image is C band, HH, descending orbit, right look, FINE mode. Inc. angle 39-42 degrees.

Radarsat image of Mont Beuvray, site of Bibracte at left, and Autun at right.

Additional new imagery has been acquired, including NASA ASTER data. These will added soon.


Monday, April 28, 2008

Putting the villages on the map in DR Congo

Hundreds of villagers are helping to map parts of the Democratic Republic of Congo where thick forest and conflict have prevented effective mapping.

So far about 190 villages have been found in one area of Bandundu province where old maps show only 30, UK-based charity The Rainforest Foundation says.

Most maps are produced from satellite images taken from above, but this project is using handheld GPS units. The map is intended to aid post-war planning and timber permit allocations.

A five-year conflict in DR Congo ended in 2003.

"In one of the sectors of the territory that the groups are mapping at the moment, there are something like 190 villages, but on the official map there are about 30," Cath Long of the Rainforest Foundation which is organising the project told the BBC's Network Africa.

She said millions of Congolese depend on the forest for their existence.

"The real worry is that permits to cut timber, permits to extract resources will be given to external companies without recognising the fact that people are already there and already using the forest," she said.

The charity hopes the map will be ready for a government meeting in May on forest and land.

The government has already allocated parts of the territory to 11 logging concessions, it says.

DR Congo is home to one of the word's largest rainforests and has huge reserves of gold, diamonds, copper and coltan, used to make mobile phones.

Correspondents say these riches have been a key factor in the civil wars, instability and bad government the country has known since independence.

Source :

PSLV-C9 carrying CARTOSAT-2A blasts off from Sriharikota

BANGALORE (AFP) � An Indian rocket blasted off and successfully launched a cluster of 10 satellites in a single mission Monday, marking a milestone for the country's 45-year-old space programme.
The PSLV rocket lifted off at 9:20 am (0350 GMT) from the Sriharikota space station in southern India in clear weather, leaving behind a massive trail of orange and white smoke, on its 13th flight. ( Watch Video )
"The mission was perfect," G. Madhavan Nair, chairman of the Bangalore-based Indian Space Research Organisation (ISRO), said after the launch telecast live by the public broadcaster Doordarshan. "Team ISRO has done it again."
"It is a historic moment for us because it is the first time that we have launched 10 satellites in a single mission," he added, congratulating Indian scientists who broke out into applause at the mission control centre.
The rocket's unprecedented payload included an Indian remote-sensing satellite known as the Cartosat-2A, a mini satellite and eight so-called nanosatellites developed by foreign research institutions, including those from Germany and Canada.
The satellites were deployed in orbit within minutes of each other in a rare space feat, with the entire mission lasting about 20 minutes.

India started its space programme in 1963, and has since developed and put several of its own satellites into space. It has also designed and built launch rockets to reduce dependence on overseas space agencies.
Source :

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PSLV-C9 ready to surge into space

CHENNAI: The 50-hour countdown for the lift-off of the Polar Satellite Launch Vehicle (PSLV-C9) from Sriharikota, Andhra Pradesh, on Monday morning is under way. The vehicle will put as many as 10 satellites in orbit.

If the countdown, which began at 7.23 a.m. on Saturday proceeds without any “hold,” the PSLV-C9 will surge into space from the world-class second launch pad at 9.23 a.m. on Monday.

Nano satellites

The challenge of this mission is that the fourth stage of the rocket should fire the 10 satellites into the orbit, one after another, in a timed sequence without any collision, said Indian Space Research Organisation (ISRO) officials. Two satellites belong to ISRO and other eight, called nano satellites, are from different countries. These are very small satellites and all of them together weigh only 50 kg.

Although the PSLV has successfully launched multiple satellites three times earlier (three satellites each on May 26, 1999 and October 22, 2001 and four satellites on January 10, 2007), this is the first time that ISRO is attempting to put in orbit as many as 10 satellites using a single rocket.

“It is a good experience to launch so many satellites” because it was quite an involved and complex task, said B.N. Suresh, former Director, Vikram Sarabhai Space Centre (VSSC), Thiruvananthapuram. The VSSC has built the PSLV-C9 which is a four-stage vehicle.

“Core-alone” version

It is the “core-alone” version of the PSLV that will put the satellites in orbit. This version does not carry six strap-on booster motors that surround the first stage of the “standard version.” The core-alone, therefore, is a lighter vehicle weighing 230 tonnes instead of the standard configuration which weighs 295 tonnes.

The two Indian satellites being carried are Cartosat-2A and Indian Mini Satellite (IMS-1). Cartosat-2A, which weighs 690 kg, is a remote-sensing satellite and its images will have a resolution of one metre.

The images will be used in making maps which will provide valuable information in planning urban infrastructure, rural roads, ring roads, and settlements. They will also be used in defence applications.

The IMS-1, which weighs 83 kg, is also a remote-sensing satellite. The images sent down by its two cameras can be used to monitor features on the earth such as its vegetation and water bodies. The ISRO Satellite Centre, Bangalore, has built the two satellites.

Six of the eight nano satellites are clustered together and are named NLS-4. The University of Toronto, Canada, has developed the NLS-4. It comprises Cute 1.7 and SEEDS, both built in Japan while the remaining four – CAN-X2, AAUSAT-II, COMPASS-1 and Delphi-C3 —were built in Canada, Denmark, Germany and the Netherlands respectively.

The two other nano satellites, NLS-5 and Rubin-8, belong to the University of Toronto and Germany. Building these nano satellites amounted to “a good experimentation for several universities,” said Dr. Suresh.

Demanding mission

ISRO officials said it would be a demanding mission because the fourth stage of the PSLV-C9 would have to be re-oriented each time it ejected a satellite into orbit.


Global and Continental Temperature Change, 1900 - 2000

Sunday, April 27, 2008

Another Global Warming Threat: The Greenland Lake


On July 29, 2006, there was a roughly 11-billion-gallon (0.044–cubic kilometer) lake that stretched more than two square miles (5.6 square kilometers) and covered the western portion of Greenland’s massive ice sheet. In the span of 16 hours, it was gone. The reason: water pressure cracked through the more than half-mile (980-meter) thick ice, draining the lake as its water rushed through the new funnel and gathered below the giant ice sheet, raising it nearly four feet (1.2 meters) and moving it nearly three feet (0.8 meter) to the north.

“My co-workers and I had proposed models [in which] meltwater gets to the bed when a lake fills a crevasse, thus driving the crack down,” says glaciologist Richard Alley of Pennsylvania State University who was not involved in the study. Now glaciologist “[Sarah] Das [and her colleagues] have observed it—more than Niagara plunging into Greenland!”

In fact, Niagara Falls’s flow per second can be as fast as 202,000 cubic feet (5,720 cubic meters) of water; the glacial lake drained at pace of 307,237 cubic feet (8,700 cubic meters) per second. The meltwater below the glacier then flowed away through channels in the rock below, allowing the ice to subside back to its normal position.

Das of the Woods Hole Oceanographic Institution in Massachusetts, geophysicist Ian Joughin of the University of Washington in Seattle and an international team were the first scientists to observe and report such rapid drainage of a meltwater lake. They also used satellite and ground-level observations from September 2004 to August 2007 to determine that the glaciers of western Greenland are speeding up in their flow to the sea due to a combination of meltwater and more icebergs “calving,” or breaking off of the glaciers.

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CORAL REEFS: Rainforests of Oceans

Coral Reefs

coral reef

Coral Reefs are the “Rainforests” of the ocean. Reefs are ecologically important ecosystems and have a high biodiversity that serves as a storage bank of rich genetic resources. They are a source of food and medicine, and they protect the coast from wave erosion.

Profile of coral reef with typical reef “zones”

Profile of coral reef with typical reef “zones”

Credit: NOAA

Corals are marine animals related to jellyfish and anemones. Both colonial and solitary corals catch plankton (microscopic plants and animals) and other suspended food particles with arm-like tentacles, which feed a centrally located mouth. Most hard corals also host symbiotic algae, a long-standing and successful partnership. These algae provide them with an additional food source through photosynthesis. Coral reefs are formed by corals that secrete hard calcareous (aragonite) exoskeletons, giving them structural rigidity. These colonial “hard corals” form elaborate finger-shaped, branching, or moundshaped structures and can create masses of limestone that stretch for tens or even hundreds of miles.

Although corals have a wide distribution in the world’s oceans, the varieties that form reefs are typically restricted to relatively shallow, warm tropical waters between latitudes 30° north and 30° south. Clean, clear water is essential to their health. Once coral larvae settle on a hard substrate and become established, colonies can arise if conditions are suitable for growth. Given enough time, coral colonies become thickets. As coral thickets build upward on the skeletal remains of older colonies, a reef is established. Today, richly diverse coral reefs are found in the tropics along coastlines, on the margins of volcanic islands, and as isolated coral atolls.

coral reef map

There are two distinct regions in which coral reefs are primarily distributed: the Wider Caribbean (Atlantic Ocean) and the Indo-Pacific (from East Africa and the Red Sea to the Central Pacific Ocean).

coral reef coral reef coral reef coral reef

  • The diversity of coral is far greater in the Indo-Pacific, particularly around Indonesia, the Philippines, and Papua New Guinea. Many other groups of marine fauna show similar patterns, with a much greater diversity in the Indo-Pacific region.
  • Although they possess a smaller number of species the corals of the Atlantic are still unique, with few common species between the two regions .

coral reef map

The majority of reef building corals are found within tropical and subtropical waters. These typically occur between 300 north and 300 south latitudes. The red dots on this map show the location of major stony coral reefs of the world. Credit:NOAA

Coral reefs are found in about 100 countries. Coral Reefs are home to over 25 percent of all marine life and are among the world’s most fragile and endangered ecosystems. In the last few decades over 35 million acres of Coral Reefs have been obliterated. Reefs off of 93 countries have been damaged . When corals are stressed by high temperature, ultraviolet light or other environmental changes, they lose their symbiotic algal cells, and appear white (the white skeleton is actually visible through the transparent tissue). Depending on the intensity and duration of the stress, the corals may recover or die.

Coral reef Tarawa, Kiribati

Tarawa, Kiribati

NOAA Image

If the present rate of destruction continues, 70% of the world’s coral reefs will be destroyed within the next few decades.

Coral Bleaching

Climate change will destroy the world’s great coral reefs within a century, according to a report by German and Australian marine scientists.Researchers say governments must take action now to reduce the emissions of gases such as carbon dioxide, which are thought to be behind a rise in average global temperatures.

bleached coral reef
A slight rise in temperature can bleach coral like this

The scientists combined their coral expertise with the latest climate models to project what is likely to happen to the world’s greatest reefs if global warming remains unchecked. Their study suggests the unique marine environments will increasingly become victim to a process known as coral bleaching.

A slight rise in maximum water temperatures - only one to two degrees - can stress the corals. This causes them to expel the microscopic organisms, known as zooxanthellae, which color their tissues and provide them with essential nutrients.

If the zooxanthellae do not return, the corals will die. In 1998 every reef system in the world’s tropical oceans were affected by some degree of bleaching. The report says the frequency and intensity of bleaching is set to rise.

The report’s lead author is Professor Ove Hoegh-Guldberg, an expert on coral bleaching at Sydney University. Coral reefs could be eliminated from most areas of the world by 2100, Even the world’s largest reef - the Great Barrier Reef off Australia - could be dead within 30 years unless measures are taken now to slow climate change.

Coral Reef Bleaching

What are Corals?

NOAA Image

Coral is a general term used to describe a group of cnidarians, which indicates the presence of skeletal material that is embedded in the living tissue or encloses the animal altogether. -National Oceanic and Atmospheric Administration, U.S. Dept. of Commerce. “Glossary of Coral Reef Terminology.”

NOAA Image

Corals themselves are tiny animals which belong to the group cnidaria (the “c” is silent). Other cnidarians include hydras, jellyfish, and sea anemones. Corals are sessile animals, meaning they are not mobile but stay fixed in one place.They feed by reaching out with tentacles to catch prey such as small fish and planktonic animals.

Corals are anthozoans, the largest class of organisms within the phylum Cnidaria. Comprising over 6,000 known species, anthozoans also include sea fans, sea pansies and anemones. Stony corals (scleractinians) make up the largest order of anthozoans, and are the group primarily responsible for laying the foundations of, and building up, reef structures. For the most part, scleractinians are colonial organisms composed of hundreds to hundreds of thousands of individuals, called polyps.

Corals live in colonies consisting of many individuals, each of which is called polyp. They secrete a hard calcium carbonate skeleton, which serves as a uniform base or substrate for the colony. The skeleton also provides protection, as the polyps can contract into the structure if predators approach. It is these hard skeletal structures that build up coral reefs over time. The calcium carbonate is secreted at the base of the polyps, so the living coral colony occurs at the surface of the skeletal structure, completely covering it. Calcium carbonate is continuously deposited by the living colony, adding to the size of the structure. Growth of these structures varies greatly, depending on the species of coral and environmental conditions– ranging from 0.3 to 10 centimeters per year. Different species of coral build structures of various sizes and shapes (”brain corals,” “fan corals,” etc.), creating amazing diversity and complexity in the coral reef ecosystem. Various coral species tend to be segregated into characteristic zones on a reef, separated out by competition with other species and by environmental conditions.

coral reef polyps

Most corals are made up of hundreds of thousands individual polyps like this one. Many stony coral polyps range in size from one to three millimeters in diameter. Anatomically simple organisms, much of the polyp’s body is taken up by a stomach filled with digestive filaments. Open at only one end, the polyp takes in food and expels waste through its mouth. A ring of tentacles surrounding the mouth aids in capturing food, expelling waste and clearing away debris. Most food is captured with the help of special stinging cells called nematocysts which are inside the polyp’ outer tissues, which is called the epidermis. Calcium carbonate is secreted by reef-building polyps and forms a protective cup called a calyx within which the polyps sits. The base of the calyx upon which the polyp sits is called the basal plate. The walls surrounding the calyx are called the theca. The coenosarc is a thin band of living tissue that connect individual polyps to one another and help make it a colonial organism.

As members of the phylum Cnidaria, corals have only a limited degree of organ development. Each polyp consists of three basic tissue layers: an outer epidermis, an inner layer of cells lining the gastrovascular cavity which acts as an internal space for digestion, and a layer called the mesoglea in between

coral reef

The diagram above shows the anatomy of a nematocyst cell and its “firing” sequence, from left to right. On the far left is a nematocyst inside its cellular capsule. The cell’s thread is coiled under pressure and wrapped around a stinging barb. When potential prey makes contact with the tentacles of a polyp, the nematocyst cell is stimulated. This causes a flap of tissue covering the nematocyst—the operculum—to fly open. The middle image shows the open operculum, the rapidly uncoiling thread and the emerging barb. On the far right is the fully extended cell. The barbs at the end of the nematocyst are designed to stick into the polyp’s victim and inject a poisonous liquid. When subdued, the polyp’s tentacles move the prey toward its mouth and the nematocysts recoil back into their capsules.

All coral polyps share two basic structural features with other members of their phylum. The first is a gastrovascular cavity that opens at only one end. At the opening to this cavity, commonly called the mouth, food is consumed and some waste products are expelled. A second feature all corals possess is a circle of tentacles, extensions of the body wall that surround the mouth. Tentacles help the coral to capture and ingest plankton for food, clear away debris from the mouth, and act as the animal’s primary means of defense.

coral polyps

coral polyps

Credit:University of Texas

While coral polyps have structurally simple body plans, they possess several distinctive cellular structures. One of these is called a cnidocyte—a type of cell unique to, and characteristic of, all cnidarians. Found throughout the tentacles and epidermis, cnidocytes contain organelles called cnidae, which include nematocysts, a type of stinging cell. Because nematocytes are capable of delivering powerful, often lethal toxins, they are essential to capturing prey, and facilitate coralline agonistic interactions

Most corals, like other cnidarians, contain a symbiotic algae called zooxanthellae, within their gastrodermal cells. The coral provides the algae with a protected environment and the compounds necessary for photosynthesis. These include carbon dioxide, produced by coral respiration, and inorganic nutrients such as nitrates, and phosphates, which are metabolic waste products of the coral. In return, the algae produce oxygen and help the coral to remove wastes. Most importantly, they supply the coral with organic products of photosynthesis. These compounds, including glucose, glycerol, and amino acids, are utilized by the coral as building blocks in the manufacture of proteins, fats, and carbohydrates, as well as the synthesis of calcium carbonate (CaCO3). The mutual exchange of algal photosynthates and cnidarian metabolites is the key to the prodigious biological productivity and limestone-secreting capacity of reef building corals.


(Courtesy Scott R. Santos, of the State University of New York at Buffalo)

Zooxanthellae often are critical elements in the continuing health of reef-building corals. As much as 90% of the organic material they manufacture photosynthetically is transferred to the host coral tissue . If these algal cells are expelled by the polyps, which can occur if the colony undergoes prolonged physiological stress, the host may die shortly afterwards. The symbiotic zooxanthellae also confers its color to the polyp. If the zooxanthellae are expelled, the colony takes on a stark white appearance, which is commonly described as “coral bleaching”

Coral Reef Facts

  • Fact: Coral reefs are among the oldest ecosystems on Earth.
  • Fact: Coral reefs are the largest living structure on the planet.
  • Fact: Although coral reefs cover less than 1% of the Earth’s surface, they are home to 25% of all marine fish species.
  • Fact: 500 million people rely on coral reefs for their food and livelihoods.
  • Fact: Coral reefs form natural barriers that protect nearby shorelines from the eroding forces of the sea, thereby protecting coastal dwellings, agricultural land and beaches.
  • Fact: Without the existence of coral reefs, parts of Florida would be under water.
  • Fact: Coral reefs have been used in the treatment of cancer, HIV, cardiovascular diseases and ulcers.
  • Fact: Corals’ porous limestone skeletons have been used for human bone grafts.
  • Fact: It is estimated that coral reefs provide $375 billion per year around the world in goods and services.
  • Fact: If the present rate of destruction continues, 70% of the world’s coral reefs will be destroyed by the year 2050.

How Can You Help Save Coral Reefs?

This year, help us rescue the coral reefs of Indonesia — located in the heart of the Coral Triangle. The seas surrounding this archipelago contain the world’s highest fish and coral diversity. Indonesia’s waters are also home to whales, dolphins, dugongs and sea turtles.

However, threats such as destructive fishing practices and coastal development are straining marine resources beyond sustainable levels. With your help, we can protect Indonesia’s beautiful seascapes, have a lasting impact on conservation and Rescue the Reef!


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Saturday, April 26, 2008

The universe


The universe can be defined as the whole of existing things from the scale of sub-micron to outer space. It consists of approximately 100 000 000 000 (one hundred thousand million) galaxies, each containing approximately 100 000 000 000 stars. The most distant objects that we know of are quasars, some 16 000 000 000 light years away. The age of the universe is approximately 15 000 million years (Ma) or 15 billion years (Ga), though there is some debate on this.

Origin of the universe

Recent astronomical observations have shown that the universe is expanding away from a local group of galaxies. This appears to have begun by a huge explosion some 15 billion years ago. This 'Big Bang' is the most accepted theory which best explains our present observations on the structure of the universe.

In the 'Big Bang' theory, the universe began with a primeval fireball which contained all matter and energy within the universe concentrated within a single body. During the first few minutes, the expansion was dominated by radiation at temperatures of 1011 K (The Kelvin scale is used to measure very high and very low temperatures, 0° C = 273° K). Matter consisted of only protons, neutrons and electrons. Within three to four minutes, the effects of radiation diminished and more complex forms of matter (such as the deuterium nucleus : neutron+proton) evolved. Later, most of the matter became hydrogen (a proton+electron) at a temperature of 109 K.

Hundreds of millions of years after the initial 'Big Bang', immense condensations of matter occurred, eventually forming galaxies. Our own solar system is only some 4600 million years old.


Composition of the universe

The universe is composed mainly of hydrogen with approximately 20% helium. All other chemical elements comprise less than 1%. All elements originated as hydrogen. Within the first two minutes of the 'Big Bang', hydrogen atoms fused together and helium and lithium were produced. Element production ceased at this point in the 'Big Bang' and all other elements heavier than lithium (Li) were produced during later fusion reactions within the interiors of stars.

During supernova events when massive stars exhaust their nuclear fuel in only a few days to months, collapse occurs and the enormous amount of energy caused by intense neutron flux produces the heavier elements such as uranium and gold. The violent explosion also distributes these elements back into space. As the formation of elements proceeds through innumerable star cycles, forming and exploding, the gas and dust produced is slowly enriched in the heavier elements.


The largest objects in the universe are galaxies which can be divided into several types depending upon their shape:

  • Spiral galaxies are the most common and distinctive type (e.g. the Milky Way).
  • Barred spiral galaxies are not as compact as spiral galaxies and have an inner bar which comprises the centre of the galaxy from which arms reach out.
  • Elliptical galaxies are small and difficult to observe because of their low luminosity.
  • Irregular galaxies comprise only a small percentage of all types and lack any distinctive symmetry.
A spiral galaxy in Antlia
A spiral galaxy in Antlia, NGC 2997. Photo: © David Malin/Anglo-Australian Observatory.
A barred spiral galaxy
A barred spiral galaxy, NGC 1365, in Fornax. Photo: © David Malin/Anglo-Australian Observatory.

An elliptical galaxy
An elliptical galaxy, NGC 5078 and its distorted companion IC 879, in Hydra. Photo: © David Malin/Anglo-Australian Observatory.
Large Magellanic Cloud
Large Magellanic Cloud. Photograph from UK Schmidt plates. Photo: © David Malin/Anglo-Australian Observatory/Royal Obs. Edinburgh



Stars are the most familiar objects in the universe as we can see them almost every night with the naked eye. They vary in size from small white dwarfs to super giants. There are approximately 1022 stars in the universe. They are being formed in galaxies all the time (e.g. nearby stars in the Orion Nebula were born less than one million years ago). Stars shine as they burn-up their nuclear fuel and eventually die. Our sun is an example of a common though smaller than average sized star. It formed approximately 4.6 billion years ago and will most likely last for another 4.6 billion years before it dies out and engulfs all of our solar system's inner planets, including the Earth.

Groupings of stars as seen from the Earth are known as constellations. They are accidental groupings (that is, they are not in any way related to each other).

The luminosity of a star is a measure of its total energy output. The luminosity scale is measured relative to our own sun (a luminosity of 1). The luminosity of stars varies widely from 10-6 to 5 x 105. The temperature of a star is always given as its surface temperature. These range from 3500° K to 80 000° K (The Kelvin scale is used to measure very high and very low temperatures, 0° C = 273° K). The colour of a star is closely related to its surface temperature. The hottest stars are blue, followed by white, and the coolest stars are yellow, to orange and finally red in colour with decreasing temperature.

  • Supergiants and giant stars are those of enormous size and great luminosity despite having low surface temperatures.
  • White dwarfs are relatively hot small stars with a great density.
  • Neutron stars contain matter which is 1014 times denser than water yet have diameters of only 20 km.
  • Pulsars are small rapidly rotating objects (up to 30 times per second) which emit radiation at regular intervals.
  • Quasars are extremely bright distant objects that extend to the limit of the universe as we know it.
  • Black holes are stars that have collapsed under their own gravitational forces. They are of such high density that their gravitational force is strong enough to even prevent any light or matter escaping.
South celestial pole over water
South celestial pole over water. Photo: © David Miller/DMI.
The super giant Antares and surrounding nebula
The super giant Antares and surrounding nebula. Photograph from UK Schmidt plates. Photo: © David Malin/Anglo-Australian Observatory.

Importance of the sun

The Earth obtains most of its heat and light energy from the sun. This solar energy causes water evaporated on the surface of the Earth to rise into the atmosphere before precipitating elsewhere on the Earth's surface. Wind is a result of air circulation caused by solar heating. The temperature of the surface of the sun is 6000° K (The Kelvin scale is used to measure very high and very low temperatures, 0° C = 273° K).

The temperature at the centre of the sun is 15 000 000° K.

The sun consists of:

  • an interior which contains most of the mass of the sun and where the sun's energy is produced
  • the photosphere is the layer from which the sun's energy escapes and from where light comes from (thickness of 1000 km)
  • the chromosphere has a very low density and is red in colour due to clouds of hydrogen gas (thickness of 500 km)
  • the corona can only be seen during a total eclipse, has a low density and has a temperature of 1 500 000° K

Sunspots are dark markings on the photosphere of the sun between 5° - 35° north and south of the sun's equator. The sun's energy is produced through nuclear fusion reactions in which hydrogen atoms are fused together to form helium.

Deformed sun at sunrise
Deformed sun at sunrise. Photo: © David Miller/DMI.
Solar eclipse
Solar eclipse 11 July, 1991, La Paz, Mexico. Diamond ring effect. Photo: © Akira Fujii/DMI.

Measuring astronomical objects

Electromagnetic radiation is the key to our understanding of the universe. It includes all forms of energy that travel through space in the form of waves, visible light, X-rays, ultraviolet, infrared and radiowaves. The electromagnetic spectrum is made up of radiation of varying wavelengths travelling at the speed of light. It is measured and detected using a number of different instruments.

When any element is heated, its gas emits a characteristic spectrum. The chemical composition of many objects can then be determined by examining the spectra of its heated vapours. Conversely, a cool gas absorbs the wavelengths characteristic of the atoms in it.

The fundamental measure of distance in space is the light year which is the distance that light travels through space in one year (9.46 x 1012 km). The speed of light is 300 000 km per second.

The Astronomical Unit (AU) is the mean distance between the Earth and our sun (measured in kilometres).


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Friday, April 25, 2008

Global Warming Update

What with catastrophic global warming proceeding at such an alarming rate, regular updates are required for people to stay up to date on our planet's sweltering doom. From Science Daily:

The Antarctic deep sea is getting colder, which might stimulate the circulation of the oceanic water masses. This is the first result of the Polarstern expedition of the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association that has just ended in Punta Arenas/Chile. At the same time satellite images from the Antarctic summer have shown the largest sea-ice extent on record.

Ninety percent of the ice on this planet is in the Antarctic region. If ice is growing there, that means we can forget about the rising seas scenario Al Gore et al. have used to frighten money out of the gullible.

So far the only tangible symptom of the global warming crisis is rising food prices caused by the biofuels boondoggle — unless you count global warming having killed the Loch Ness Monster.


Sedimentary Rocks

Rivers, oceans, winds, and rain runoff all have the ability to carry the particles washed off of eroding rocks. Such material, called detritus, consists of fragments of rocks and minerals. When the energy of the transporting current is not strong enough to carry these particles, the particles drop out in the process of sedimentation. This type of sedimentary deposition is referred to as clastic sedimentation. Another type of sedimentary deposition occurs when material is dissolved in water, and chemically precipitates from the water. This type of sedimentation is referred to as chemical sedimentation. A third process can occur, wherein living organisms extract ions dissolved in water to make such things as shells and bones. This type of sedimentation is called biogenic sedimentation. Thus, there are three major types of sedimentary rocks: Clastic Sedimentary Rocks, Chemical Sedimentary Rocks, and Biogenic Sedimentary Rocks.

Clastic Sediments

Classification - Clastic sedimentary particles are classified in terms of size

Name of Particle

Size Range

Loose Sediment

Consolidated Rock

Boulder >256 mm Gravel Conglomerate or Breccia (depends on rounding)
Cobble 64 - 256 mm Gravel
Pebble 2 - 64 mm Gravel
Sand 1/16 - 2mm Sand Sandstone
Silt 1/256 - 1/16 mm Silt Siltstone
Clay <1/256> Clay Claystone, mudstone, and shale

The formation of a clastic sedimentary rock involves three processes:

  1. Transportation - Sediment can be transported by sliding down slopes, being picked up by the wind, or by being carried by running water in streams, rivers, or ocean currents. The distance the sediment is transported and the energy of the transporting medium all leave clues in the final sediment that tell us something about the mode of transportation.
  1. Deposition - Sediment is deposited when the energy of the transporting medium becomes too low to continue the transport process. In other words, if the velocity of the transporting medium becomes too low to transport sediment, the sediment will fall out and become deposited. The final sediment thus reflects the energy of the transporting medium.

  2. Diagenesis - Diagenesis is the process that turns sediment into rock. The first stage of the process is compaction. Compaction occurs as the weight of the overlying material increases. Compaction forces the grains closer together, reducing pore space and eliminating some of the contained water. Some of this water may carry mineral components in solution, and these constituents may later precipitate as new minerals in the pore spaces. This causes cementation, which will then start to bind the individual particles together. Further compaction and burial may cause recrystallization of the minerals to make the rock even harder.

    Other conditions present during diagenesis, such as the presence of absence of free oxygen may cause other alterations to the original sediment. In an environment where there is excess oxygen (Oxidizing Environment) organic remains will be converted to carbon dioxide and water. Iron will change from Fe2+ to Fe3+, and will change the color of the sediment to a deep red (rust) color. In an environment where there is a depletion of oxygen (Reducing Environment), organic material may be transformed to solid carbon in the form of coal, or may be converted to hydrocarbons, the source of petroleum.

Textures of Clastic Sedimentary Rocks

When sediment is transported and deposited, it leaves clues to the mode of transport and deposition. For example, if the mode of transport is by sliding down a slope, the deposits that result are generally chaotic in nature, and show a wide variety of particle sizes. Grain size and the interrelationship between grains gives the resulting sediment texture. Thus, we can use the texture of the resulting deposits to give us clues to the mode of transport and deposition.

Sorting - The degree of uniformity of grain size. Particles become sorted on the basis of density, because of the energy of the transporting medium. High energy currents can carry larger fragments. As the energy decreases, heavier particles are deposited and lighter fragments continue to be transported. This results in sorting due to density.

If the particles have the same density, then the heavier particles will also be larger, so the sorting will take place on the basis of size. We can classify this size sorting on a relative basis - well sorted to poorly sorted. Sorting gives clues to the energy conditions of the transporting medium from which the sediment was deposited.


    • Beach deposits and wind blown deposits generally show good sorting because the energy of the transporting medium is usually constant.

    • Stream deposits are usually poorly sorted because the energy (velocity) in a stream varies with position in the stream.

Rounding - During the transportation process, grains may be reduced in size due to abrasion. Random abrasion results in the eventual rounding off of the sharp corners and edges of grains. Thus, rounding of grains gives us clues to the amount of time a sediment has been in the transportation cycle. Rounding is classified on relative terms as well.

Chemical Sediments and Sedimentary Rocks

Cherts - chemically precipitated SiO2

Evaporites - formed by evaporation of sea water or lake water. Produces halite (salt) and gypsum deposits by chemical precipitation as concentration of solids increases due to water loss by evaporation.

Biogenic Sediments and Sedimentary Rocks

Limestone - calcite (CaCO3) is precipitated by organisms usually to form a shell or other skeletal structure. Accumulation of these skeletal remains results in a limestone.

Diatomite - Siliceous ooze consisting of the remains of radiolarian or diatoms can form a light colored soft rock called diatomite.

Coal - accumulation of dead plant matter in large abundance in a reducing environment (lack of oxygen).

Oil Shale - actually a clastic sedimentary rock that contains a high abundance of organic material that is converted to petroleum during diagenesis.

Features of Sedimentary Rocks That Give Clues to the Environment of Deposition

Stratification and Bedding

  • Rhythmic Layering - Alternating parallel layers having different properties. Sometimes caused by seasonal changes in deposition (Varves). i.e. lake deposits wherein coarse sediment is deposited in summer months and fine sediment is deposited in the winter when the surface of the lake is frozen.
  • Cross Bedding - Sets of beds that are inclined relative to one another. The beds are inclined in the direction that the wind or water was moving at the time of deposition. Boundaries between sets of cross beds usually represent an erosional surface. Very common in beach deposits, sand dunes, and river deposited sediment.
  • Graded Bedding - As current velocity decreases, first the larger or more dense particles are deposited followed by smaller particles. This results in bedding showing a decrease in grain size from the bottom of the bed to the top of the bed.
  • Non-sorted Sediment - Sediment showing a mixture of grain sizes results from such things as rockfalls, debris flows, mudflows, and deposition from melting ice.

Surface Features
  • Ripple Marks - Characteristic of shallow water deposition. Caused by waves or winds.

  • Mudcracks - result from the drying out of wet sediment at the surface of the Earth. The cracks form due to shrinkage of the sediment as it dries.

  • Raindrop Marks - pits (or tiny craters) created by falling rain. If present, this suggests that the sediment was exposed to the surface of the Earth.

  • Fossils - Remains of once living organisms. Probably the most important indicator of the environment of deposition.
    • Different species usually inhabit specific environments.

    • Because life has evolved - fossils give clues to relative age of the sediment.

    • Can also be important indicators of past climates.


  • Iron oxides and sulfides along with buried organic matter give rocks a dark color. Indicates deposition in a reducing environment.

  • Deposition in oxidizing environment produces red colored iron oxides.

Sedimentary Facies

A sedimentary facies is a group of characteristics which reflect a sedimentary environment different from those elsewhere in the same deposit. Thus, facies may change vertically through a sequence as a result of changing environments through time. Also, facies may change laterally through a deposit as a result of changing environments with distance at the same time.

Common Sedimentary Environments

  • Non-marine environments

    • Stream sediments

    • Lake sediments

    • Glacial (ice deposited) sediments

    • Eolian (wind deposited) sediments

  • Continental Shelf sediments

    • Estuarine sediments

    • Deltaic sediments

    • Beach sediments

    • Carbonate shelf sediments

    • Marine evaporite sediments

  • Continental slope and rise sediments

    • Turbidites

    • Deep Sea Fans

    • Sediment drifts

  • Deep Sea Sediments

    • Deep -Sea oozes

    • Land-derived sediments
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