Whether the Weather

"Whether the weather be cold,

or whether the weather be hot,

We'll weather the weather

whatever the weather,

Whether we like it or not.'

In 2014, the British Isles were
hit hard by a large storm with high winds
and 50 foot waves.

When most people picture Britain's normal weather patterns, cyclones such as hurricanes don't usually come to mind. Great Britain is located out in the Atlantic, therefore far away from the low-pressure ares such as the Caribbean that it doesn't get caught up in cyclones. However, that doesn't mean it hasn't been entirely unaffected.

According to Keller and Devecchio a cyclone is large low-pressure system with winds circulating toward the center. Cyclones that occur away from tropic regions are called "extropical," while tropical cyclones are those which occur near the 5 and 20 degree latitude regions where the water is warm.

Strong westerly winds brought high
winds, high waves, and flood warnings to
western parts of the UK. Pictured above
is Dawlish (Devon) taking a beating.

According to Livescience.com, between 1851 and 2010, the UK was only hit by 10 cyclones coming at most within only 200 miles from Ireland! How do these extropical storms show up there? Dennis Feltgen from the National Hurricane Center says that as warm storms like hurricanes move across the Atlantic Ocean, they are no longer fed by the warm water. Unlike tropical storms which form when warm air rises to make spiraling clouds extropical cyclones are fed by cold, dry air, making their cores very cold, (Keller and Deveccio, 333).

To warm people of severe weather, the UK's Met Office offers map which show the movement of potentially dangerous forces in different colors. You can find the website here!

Sink or Swim

We've probably all experienced minor damaging effects of a natural disaster at some point in our lives, (if not, you're very fortunate!) For some living in California, it might have been an earthquake. For me personally, it was a bit of minor flooding in my garage. While soggy floorboards and broken vases can be replaced, what do you do if the earth swallows up your house?

Subsidence

According to the British Geological Survey, subsidence is defined as ground failure when the earth shrinks downward. When water wears bedrock down, the earth above it collapses into either a big circular pit or a long depressed line. When water, either from under or above ground percolates through the bedrock, the rock (like limestone) can easily be dissolved. We call this process dissolution. (Keller and Devecchio, 258)

Sink hole in a back garden, St. Alban's, UK

The British Geological Survey maps out
hazardous areas based on ground stability.
Source: BGS

Recently I read a 2014 article from a British online magazine asking why there were so many sinkholes popping up in the UK. The fact that the author of the article was surprised about there being excess moisture in the ground in England of all places was a bit funny. The UK is known for being very rainy, and crowded cities with poor drainage provide perfect conditions for subsidence issues.

Certain parts of Britain have proven to be more susceptible to subsidence due to the types of rock found there. Places like Cheshire and the Vale of York in the south east of England, for example is chock full (haha) of gypsum, which is basically chalk, and soft clay.

To decrease hazards, the British Geological survey is constantly working to create maps indicating places where the ground is weak and likely to collapse, and predicts places where the ground is likely to sink in or erode.

What a Waste! : Mass Wasting in the UK

Whether it be small and slow, or large and quick, mass wasting can be a major cause of loss of property and sometimes even life. According to Keller and DeVecchio, mass wasting is the movement of earth materials down a slope.(217) Mass wasting can refer to rockfalls, debris flows and avalanches, but for the sake of time, I'll mainly be speaking about landslides.

A landslide can be classified as either falling, sliding, slumping, flow or creep:

Sliding: As large rocks travel downhill, they loosen up other smaller rocks, rushing everything on the way down

Falling: Rocks are falling from the face of a cliff

Slumping: Rocks or soil is falling down a curved slope

Flow: Particles are moving downhill in a large, mixed up mass, like avalanches and earth flows

Creep: An extremely slow rate of flowage

Making Waves

When a tsunami hits, there is nothing in the world that can stop the powerful wave from destroying everything in its path. If you've watched the news at all in the last ten years, you'll know what a tsunami looks like, and just how destructive it can be. But do you know how they begin?

A Tsunami can be caused by natural occurrences, whether that be a submarine landslide, the impact of an asteroid or meteorite, an earthquake that causes the shifting of the seafloor, or an underwater volcano (Keller and Devecchio, 102-109.)

A tsunami in Great Britain is very unlikely 

thanks to its position on the Eurasian plate.

(photo: Britishnationalparty.com)

The Lisbon tsunami and fire, 1755
(Glogster.com)

When reading about Great Britain, I was unsurprised to find that the British Isles are not really at risk of tsunamis, once again thanks to their placement on the Eurasian tectonic plate. According to the British Geological survey, there is evidence that Great Britain did suffer at least one tsunami about 8000 years ago. Thanks to geological records, scientists believe that a submarine earthquake off the coast of Norway sent waves toward the shores of Britain.

According to the Encyclopedia Brittanica, a magnitude 8 earthquake originating along the Atlantic faultiness created a tsunami powerful enough to destroy the city of Lisbon, Cornwall in 1755. With 20 foot waves, the tsunami destroyed 12,000 buildings and killed 60,000 people in the city alone.

Today, we know it is unlikely that Great Britain would be at risk of an earthquake for a few reasons. First, that the earthquakes which take place along the nearest plate boundary (the Atlantic Ridge) are too small and too far away to cause any peril. Second, that Britain hardly experiences earthquakes large enough to cause harm, given that the largest one recorded in British history was a 6.1  magnitude. It is for these reasons that there is currently no national tsunami warning system.

It's Nobody's Fault

Because of it's location on the Eurasian plate, Great Britain does not experience volcanic activity. However, Britain is home to many beautiful but dormant volcanoes, most of which are located in Scotland. Most of these volcanoes are ancient. In fact, the "super volcanoes" of Moore, Skye and Run  in western Scotland are estimated to be about 60 million years old.

Arthur's Seat, located at the highest
 point in Edinburgh is one of the most visited
volcanoes in Great Britain.
[http://www.dailymail.co.uk/travel
/travel_news/article-2853274/Scotland-
boasts-HALF-UK-s-best-volcanoes-none-
budge-stunning-Giant-s-Causeway-spot.html]

Why exactly does Great Britain have zero volcanic activity? It happens to do with it's exact location on the Eurasian tectonic plate. When tectonic plates come together, if one plate is denser than the other it will move under the lighter one. In this process of subduction, the high temperature melts rocks and creates magma. According to the British Geological Survey, when the magma comes up through the earth, it creates a volcano. However, since Great Britain is nowhere near the edges of a tectonic plate, new volcanoes don't occur.

Since volcanoes happen quite frequently in Iceland, the UK air traffic control service NATS occasionally issues "ash warnings" to help protect the European aviation industry. from massive ash clouds.

All Shook Up

Wouldn't it be great if all it took to measure earthquakes was a sheet of paper and a couple of googley eyes? In reality, measuring seismic activity (especially in the UK) is complicated, yet absolutely fascinating!

Source

According to the British Geological survey, an earthquake occurs when a fault ruptures, releasing a burst of energy. The bursts of energy create ripples called seismic waves.  When these waves travel on the surface, they are naturally called "surface waves." On the other hand, waves called "body waves" travel in the body of the earth, and are split into two groups: S waves, which travel through solids only, and P waves, which travel through solids, liquids and gasses. (Keller and DeVecchio, 59-60)

Like any country, Britain;s earthquakes are caused by the movement of tectonic plates. Because it does not lie above a major boundary line, Britain experiences mainly minor earthquakes that are relatively frequent. In Great Briatian, out of the average 50 to 60 quakes taking place, only 20 to 30 earthquakes are felt each year, and most of which are never seen as posing any kind of threat. On to the Richter scale, the tool we use to measure the magnitude of an earthquake, earthquakes ranging below the level 4 mark are considered insignificant. Each year, most of Great Britain's earthquakes are felt at 5.

British Geological Survey provides
seismic activity stats regularly!

The British Geological Survey is a great resource which actually puts out a regularly updated list containing seismic events in the British Isles from the past 50 days. (Website can be found here!)

According to the survey, the most recent quake in Great Britain happened in Bromyard, Herefordshire. At a magnitude of 2.3, it's no wonder no one has yet reported feeling this small quake to the BGS.













Note to classmates reading this: anyone have any idea how to get rid of accidentally hi lighted portions of text?

Catch my Drift?

Map shows major plates, boundaries, and plate
movement (whybecasuescience.com)

Have you ever wondered why Earth's continents look like they should fit together, almost like a puzzle? Thanks to Geologist Alfred Wegener's, we now know that each continent is embedded in one of  the earth's tectonic plates, and that these plates are constantly moving. We call these broken up plates the lithosphere. According to Keller and DeVecchio, (Natural Hazards, 33-34), the lithospheric plates move over another layer called the asthenosphere.

In a Divergent boundary, two plates are moving away
from each other, while hot mantle is rising up from the center
forming a rift. (Keller and DeVecchio)

Great Britain is located on the Eurasian plate, yet it is not close to the division of the plates. To its right lies a Divergent boundary line (pictured right), which according to the British Geological Survey is responsible for creating more lithosphere as plates move away from each other.

However,  because it does rest on some fault lines, Great Britain experiences a few minor earthquakes each year. The earthquakes are caused by stress in the crust below Britain, which is caused by the shifting of the Eurasian plate.