Environment

What is the Severn Bore?

The Severn bore is a large surge wave which is seen in the estuary of the River Severn and is considered as one of Britain’s truly natural phenomena.

It is a tidal range and is the second highest in the world, which on occasions can reach up to approximately 5 feet in height.

This is all due to the shape of the Severn estuary, which means that the water funnels into an ever decreasing narrow channel.

The estuary narrows from being 5 miles wide in Avonmouth to just 1 mile wide in nearby Lydney and by the time the estuary reaches the Gloucestershire village of Minsterworth on the north bank of the River Severn, it is less 100 yards wide!

The depth of the river changes quickly and when the incoming tide travels up the estuary, it is routed into an ever decreasing channel.

Consequently the surge wave or a “Severn Bore” as it is known, is created and large waves going upstream are caused.

There are about 60 bores that occur throughout the world and the Severn Bore is one of the largest in the world.

Around eight occur in the UK but bores are also knwon to happen on the Rivers Seine and Gironde in France and on the Amazon in Brazil.

The biggest bore in the world is on the Hang-chou-fe in China. When Spring tides occur the wave can reach up to heights of over 25 ft (7.5 metres) reaching speeds of between 13-15 knots, which lasting for up to 14 miles!

Image Credit: The Telegraph

What is a Shelf Cloud?

A shelf cloud is a horizontal wedge-shaped cloud which hangs low in the air, and is usually associated with thunderstorms. The shelf cloud will attached itself to the underside of a parent cloud.

The rising cloud motion looks severe as it rises but it is the lower cloud that appears turbulent and wind torn.

The cool sinking air from the downdraft of the shelf cloud spreads across the surface, and the leading edge is known as the gust front.

When the warm air is drawn into the storm’s updraft and it mixes with the cooler air, the moist air condenses and this creates a rolling effect people see which usually develops into a heavy rainstorm.

A shelf cloud is also known as a “Tsunami” cloud due to what looks like a rotating motion as the cloud draws nearer to the land.

When does our Summer Solstice occur and why?

Our Summer Solstice, which is also known as “the longest Day” is celebrated on June 21st and it happens when the tilt of the planet’s semi axis in either the southern or northern hemispheres is more inclined toward the star that it orbits.

The reason for this occurence between the 20th and 22 June is because the Earth’s axial tilt towards the Sun is at it’s maximum of 23 26′. This only occurs twice a year, the other occasion is between the 20th and 22nd Decemer, which becomes the shortest day and it is all due to each time the sun reaches it’s highest point in the sky as seen in the south or north pole and determines the number of daylight hours we receive.

It is believed in ancient history that this date in June helped the people to work out the time of year, especialy for planting and haresting crops.

At Stonehenge, some historians believe that this prehistoric momument in England is true evidence that humans used the Summer Solstice in June to erect a unique stone circle to establish the date of the longest day.

When viewed from its center, the Sun is shown to rise over a certain point on the horizon and can be clearly followed on the stone circle and used as a calendar. Again it helped the people establish what time of year it was to organise their calendars for the rest of the year.

What is the Rim of Fire?

The “Rim of Fire” lies around the rim of the Pacific Ocean.

There are a number of crustal plates that meet in this area, which results in frequent volcanic and earthquake activity.

There are 452 known volcanoes in this ring and 80 per cent of the world’s largest earthquakes occur here.

Some Amazing Flower Facts

Flowers are truly amazing with all the different varieties, colours and fragrances they have together with being the reproductive organ or most seed bearing plants.

The largest flower known to us is the Rafflesia, and it weighs in around 15lbs (7 kilograms) and can only be found in Indonesia. It is known as the ‘corpse flower’ as it smells of a rotten body. It has no leaves, stem or root and the only thing seen outside the vine is the five petaled red flower.

And did you know that the Rose is a symbol of the British Royal family. The War of the Roses was so named because of the battle between the Lancastrians whose symbol was the red rose and the Yorkists whose symbol was the white rose.

Many flowers provide bees with the wax they need to make their hives while the orchid flower supplies the male bee with a special oil that he uses to attract a female.

The fragrance of a flower is produced by the essence of oil in it. Lady Slipper orchids have a special fragrant pouch which draws flies into it, they get trapped inside and then pollination takes place.

Flowers have male and female parts, male parts are called the stamens and the female part is named carpel. At the top of the stamen is the anther which generates a grain like substance called pollen.

The wind carries the pollen from the anther to the stigma which is part of the carpel, it is carried down to the ovary, then the pollen fertilizes the ovule and creates a seed, this is called pollination.

Sometimes the pollen is carried from flower to flower by insects like butterflies and birds etc as it attaches itself to the body of the insect, when they move on to the next flower the substance rubs off on the stigma and then the process starts again.

Fascinating don’t you think?