The Flying Saucer At Sunset

Lenticular clouds (Altocumulus lenticularis) are stationary lens-shaped clouds with a smooth layered appearance that form in the troposphere, usually above mountain ranges. One was spotted in Singapore recently...

Eyes Of 30,000 Honeycombs

With 30,000 individual facets, dragonflies have the most number of facets among insects. Each facet, or ommatidia, creates its own image, and the dragonfly brain has eight pairs of descending visual neurons to compile those thousands of images into one picture...

A Kaleidoscope Of Colours, Shapes And Patterns

Spectacular and innovative in design, the Flower Dome replicates the cool-dry climate of Mediterranean regions like South Africa, California and parts of Spain and Italy. Home to a collection of plants from deserts all over the world, it showcases the adaptations of plants to arid environments...

Lightning Strikes, Not Once, But Many Times

Unlike light, lightning does not travel in a straight line. Instead, it has many branches. These other branches flashed at the same time as the main strike. The branches are actually the step leaders that were connected to the leader that made it to its target...

Are You My Dinner Tonight?

A T-Rex has 24-26 teeth on its upper jaw and 24 more on its lower jaw. Juveniles have small, sharp blade-shaped teeth to cut flesh, whereas adults have huge, blunt, rounded teeth for crushing bones. Is the T-Rex a bone-crushing scavenger?

Don't Let That Branch Fall On Me! - Detecting Tree Failure

11:35 PM  , , , ,  

Singapore
June 2013

Tall trees in some parts of Singapore are being replaced more speedily with shorter, smaller species to reduce the risk of falling branches and trees toppling over. (Straits Times, 19 May 2013) There were 122 uprooted trees from January to April this year. This was a drop from 184 trees in the same period last year but more than double the 63 in 2009. (Asia One, 21 May 2013) 

The highest number was in 2011, when 636 trees were uprooted, mainly due to microbursts - a localised, powerful and descending air draft column, which produces winds at high speeds - that occurred in Mandai and Sungei Kadut that February. (Asia One, 21 May 2013) 

(Source : Straits Times)

The National Parks Board (NParks) has over the past two years stepped up its ongoing replacement planting programme taking into account shifts in weather patterns in the region. It said that incidents of "tree failure", defined as anything from broken branches to fallen trees, have been caused mainly by bouts of adverse weather conditions rather than maintenance issues. So it is replacing some familiar trees with species that might be less vulnerable to mishap, and also grouping different trees together in some areas, so they can withstand bad weather.

Trees reduce noise and air pollution. However, adverse weather conditions can result in damage to vehicles and property, and injury to passers-by.

NParks Tree Maintenance Programme

  
Trees under the National Parks Board's (NParks) charge are maintained in a healthy and stable condition. The frequency of tree inspections along major roads or areas with high human activity is at least once every 12 months. The inspection details are recorded and entered into a database for future reference. Where necessary, crown reduction pruning is carried out to reduce the weight of tree crowns so that they can better withstand strong winds.

Healthy trees can also be affected by strong winds and heavy rainfall, so it is not possible to totally eliminate risk of tree falls. Often, NParks' checks on fallen branches and trees showed that the incidences were mainly due to such adverse weather conditions, rather than poor health or tree rot.

Since 2003, NParks carries out regular exercises  to replace storm-vulnerable trees. It has also identified tree species that are more hardy, as well as those that are more storm-vulnerable. These are done together with frequent monitoring of the local weather patterns for changes in the severity of storms and intensity of rainfall.

Before removing storm-vulnerable trees, NParks plants suitable tree species in the vicinity to mitigate against the temporary loss of greenery.  Where possible, these new trees are planted before the removals.  In most cases, the number of trees planted is more than the number to be removed.  These new trees include native species that add to the biodiversity in our urban landscape.

What Are Some Signs Of Tree Failure?

  • Termite trails
(Source : Veggie Revolution)
  
  • Constrained root growth or trees planted too deep
(Source : Michigan State University Extension)
 
  • Gaping holes or cracks in trunks, especially at soil level
(Source : Hendron Tree Care)
 
  • Excessive fungi, vine, creeper or parasitic plant growth resulting in cavities and decay
(Source : Blue Jay Barrens)
 
  • Splintering branches or V-shaped forks in trunks
(Source : Michigan State University Extension & Hendron Tree Care)
 
  • Bark has mostly fallen off, exposing smooth wood underneath
(Source : Dukes Wood Project)
  
  • Trees or branches that are bleached, leafless or non-flowering unlike those around them
(Source : Crimson Canopy)
 
  • Reclining, knobbly or curved trunks
(Source : Hendron Tree Care)
  

And of course, a sharp ear to listen out for cracks when near any tree helps...
It helps if you speak softly when in nature reserves so that you don't scare away all the fauna before you come to them...  ;) 
(Source : Hendron Tree Care)
   

Are There Any Types Of Trees Which Are More Prone?

 
The Albizia tree is a fast-growing species which spread rapidly on vacant lands if left on its own. Under favourable conditions, Albizias can easily exceed 40m in height. Compared to other tree species, the wood tissues of Albizias are relatively soft, brittle and prone to breakage during storms. They are also known to suffer from pest and disease problems, such as root rot. Hence, Albizias are prone to uprooting, especially during storms.

Successful rehabilitation of a site with Albizia trees at Jalan Anak Bukit. Albizias were selectively removed,
while retaining most of the existing trees and vegetation...
(Source : NParks & SLA)

It is impossible to check every single tree in Garden City Singapore monthly. Even with a team of contractors. There are trees by the roads, trees in schools, trees near houses, trees in nature reserves, trees by boardwalks, trees in private compounds... Estimates place the number of trees planted from the tree planting campaign alone at 450,000 (45 years multiplied by a minimum of 10,000 trees each year).

Trees not only pose a danger through uprooting, 
dangers can also be caused by splintering trunks and falling branches.
(Source : Popular Mechanics)
 

Here are some tips for us drivers/trekkers/pedestrians:
  • If you are going to a wooded area or walking/parking beneath a tree, observe for signs of tree failure.
  • Do not go into a wooded area immediately after heavy rain and strong winds.
  • Report likely signs of tree failure to NParks at 1800-471-7300.

Sources



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Lightning Strikes, Not Once, But Many Times

10:16 PM  , , , ,  

Singapore
June 2013

Merlion Wayfarer was awaken by the bouts of thunder this morning. They came frequently, at a low rumble through the night. Frustrated, she opened the curtains.

This is what she saw...

She was curious - Unlike light, lightning does not travel in a straight line. Instead, it has many branches...

These other branches flashed at the same time as the main strike. Next you notice that the main strike flickers or dims a few more times in a single split second. The branches are actually the step leaders that were connected to the leader that made it to its target.


When the first strike occurs, current flows to neutralize the charge separation. This requires that the current associated with the energy in the other step leaders also flows to the ground. The electrons in the other step leaders, being free to move, flow through the leader to the strike path. So when the strike occurs, the other step leaders are providing current and exhibiting the same heat flash characteristics of the actual strike path. After the original stroke occurs, it is usually followed by a series of secondary strikes. These strikes follow only the path of the main strike; the other step leaders do not participate in this discharge.


It is very possible that the main strike is followed by 30 to 40 secondary strikes. Depending on the time delay between the strikes, it may look like one long-duration main strike, or a main strike followed by other flashes along the path of the main strike. The secondary strike can occur while the flash from the main stroke is still visible. Obviously, this may seem that the main-stroke flash lasted longer than it actually did. Similarly, the secondary strikes may occur after the flash from the main strike ends, making it appear that the main strike is flickering.



More photos are available on Merlion Wayfarer Goes Green's Picasa at :
Natural Phenomena

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World Environment Day - The Cove On Okto

5:05 AM  , , ,  

(This article is part of Merlion Wayfarer's series on Animal Welfare.)

Tonight Merlion Wayfarer will be watching The Cove.

(Source : Wikipedia)

The Cove is a 2009  film that analyzes and questions Japan's dolphin hunting culture. Told from an ocean conservationist's point of view, and filmed secretly using underwater microphones and high-definition cameras disguised as rocks, the film is a call to action to halt mass dolphin kills, change Japanese fishing practices, and to inform and educate the public about the risks, and increasing hazards, of mercury poisoning from dolphin meat. 

(Source : The Cove Movie)

The Cove highlights the fact that the number of dolphins killed in the Taiji dolphin drive hunting is several times greater than the number of whales killed in the Antarctic, and claims that 23,000 dolphins and porpoises are killed in Japan every year by the country's whaling industry. The migrating dolphins are herded into a cove where they are netted and killed by means of spears and knives over the side of small fishing boats. Dolphin hunting as practiced in Japan is unnecessary and cruel.

(Source : The Cove Movie)

It was the Academy Award Winner for Best Documentary in 2009. 

To mark World Environment Day, The Cove will shown on MediaCorp's Okto tonight at 2200 hours.
  
(Source : WotWots)


... Related Reading ...
|   "Why You Should Not Visit The Marine Life Park At RWS"   |  

   

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Project ADORE - Rehoming Strays In HDB Flats

4:50 AM  , ,  

(This article is part of Merlion Wayfarer's series on Animal Welfare.)

Every year, thousands of dogs are abandoned or impounded in Singapore. Figures from AVA state 4,050 dogs and 6,131 cats in 2004 and 1,772 dogs and 2,681 cats in 2009 (Straits Times, 26 October 2010). Despite the rapid decline in numbers, the majority of them them are put down due to a lack of space and resources to care for them. Even if they are in good health.

Mr Ricky Yeo, President of Action for Singapore Dogs (ASD), said: "It's very common to see dogs just left out in the streets... If you go to outlying areas with low human traffic, such as Lim Chu Kang, you'll find many domesticated dogs." He receives about three calls daily from pet owners who want to give up their pets. Most cite reasons such as a lack of time and resources, or a change in lifestyle, for wanting to do so.

Thus, it is most heartwarming when the media covers a positive story for these abandoned pets.

Project ADORE (ADOption and REhoming) is a pilot programme run jointly by Housing Development Board (HDB), ASD, and SPCA (Society for the Prevention of Cruelty to Animals), which allows smaller-sized mongrels to be rehomed in public flats.

To ensure that the dogs are not a nuisance to other residents, the Ministry of National Development and animal welfare groups have drawn up guidelines for owners. They must make sure the dogs go for basic obedience training, and must agree to abide by certain rules. 

Acting Manpower Minister and Senior Minister of State for National Development Tan Chuan-Jin, gave an update on the project in his Facebook post. As of April 2013, twenty-one dogs have been successfully adopted and rehomed. Mr Tan said it has been a year since the project was launched and that SPCA and ASD will extend the project for another year.

More Information...
(Source : Pets For Life)

Sources


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The Deep Sea Mystery Circle - A Love Story

2:33 AM  , , ,  

(Source : Inhabitat)
Introduced to life under the sea in high school through snorkeling, Yoji Ookata obtained his scuba license at the age of 21. At the same time, he went out and bought a brand new Nikonos, a 35mm film camera specifically designed for underwater photography. He devoted all his spare time - aside from his day job - to perfecting his art of underwater photography. Then, at age 39, he finally made the transition. He quit his office job and became a freelance underwater photographer.

(Source : Inhabitat)

But even for a man who spent the last 50 years immersed in the underwater world of sea life, the ocean proved infinitely mysterious. While diving in the semi-tropical region of Amami Oshima, roughly 80 feet below sea level, Ookata spotted something he had never seen. And as it turned out, no one else had seen it before either.

(Source : Inhabitat)

On the seabed a geometric, circular structure measuring roughly 6.5 feet in diameter had been precisely carved from sand. It consisted of multiple ridges, symmetrically jutting out from the center, and appeared to be the work of an underwater artist, carefully working with tools. For its resemblance to crop circles, Ookata dubbed his new finding a “mystery circle,” and enlisted some colleagues at NHK to help him investigate.

(Source : Inhabitat)

In a television episode that aired last week titled “The Discovery of a Century: Deep Sea Mystery Circle”, the television crew revealed their findings and the unknown artist was unmasked.

(Source : Inhabitat)

Underwater cameras showed that the artist was a small puffer fish who, using only his flapping fin, tirelessly worked day and night to carve the circular ridges. The unlikely artist - best known in Japan as a delicacy, albeit a potentially poisonous one - even takes small shells, cracks them, and lines the inner grooves of his sculpture as if decorating his piece.

Further observation revealed that this “mysterious circle” was not just there to make the ocean floor look pretty. Attracted by the grooves and ridges, female puffer fish would find their way along the dark seabed to the male puffer fish where they would mate and lay eggs in the center of the circle. In fact, the scientists observed that the more ridges the circle contained, the more likely it was that the female would mate with the male. The little sea shells weren’t just in vain either. The observers believe that they serve as vital nutrients to the eggs as they hatch, and to the newborns.

(Source : Inhabitat)

What was fascinating was that the fish’s sculpture played another role. Through experiments back at their lab, the scientists showed that the grooves and ridges of the sculpture helped neutralize currents, protecting the eggs from being tossed around and potentially exposing them to predators. It was a true story of love, craftsmanship and the desire to pass on descendants.

(Source : Inhabitat)

(The above article was retrieved from an email. Content was supplemented with photos from Inhabitat.com.)


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