Monday 26 December 2011

What landforms result from weathering and erosion?

What land shapes, or landforms, can you see created as a result of:

a) weathering of rock in situ;
b) rivers, large or small;
c) marine processes.

For a) look at the mountains that surround us.
What is affecting their rate of erosion? In Hong Kong the mountains are mostly made of granite. How different do you expect the landforms to erode from say, limestone?

You might need to think about the mineral composition of the rock, and how that reacts to chemicals in the environment; what the grain size of the rock contributes to its weathering; whether the presence of fault lines or strata affects the rock's weakness.

Also consider the weather. Here it can be hot and humid for much of the year. How would you expect sandstone, for example, to weather in this climate, as opposed to a hot, dry desert, or a cold and wet climate?

For b) think about the action of the many rivers you have seen.
You have paddled in creeks, streams and rivers large and small. You have conducted river surveys, listened to talks about estuaries and walked with rangers describing ox-bow lakes and boggy clay pits.

Draw an imaginary river from youth to old age. Write captions to mark as many different landscape features that a visitor might see. Try to include, in your diagram,

For c) look at where the land meets the water. What's going on?
You might find geospeak useful: wave, corrasion, hydraulic action, abrasion, attrition, corrosion.

Remember the many coastlines you have visited. Longshore drift on the east coast of England? Caves, stacks and Chesil beach on the south coast of England? Sand dunes at Worimi conservation land, New South Wales? Reefs and sea cliffs in Hong Kong?

For general research, try wikianswers. Youtube provides background videos. Slideshare may help if you poke about the options.

Monday 19 December 2011

Can you tell me about weathering and erosion?

No, not wrinkles, sun damage and sand blasting on mama's face.

Find out about these three other forms of weathering:
1. physical or mechanical
2. chemical
3. biological

Some ideas here. You can click to find plenty of videos about erosion from the choices on the right-hand side.

Then can you tell me how a river erodes, transports, and deposits the material it's carrying?

And the sea. What role does that play in eroding coastlines? We've had a great experience already in finding out. I think fondly of Dunwich. And here:


Think of your many seaside experiences: Chesil beach, Ladram bay, North Norfolk marshland. Where else is in your experience?

Monday 12 December 2011

What are the causes and effects of earthquakes and volcanic eruptions?

For info, readings, videos and ideas on the causes and effects of earthquakes:
The geography site, explains tectonic earthquake and volcanic earthquake.
Earthquake effects covering 'shaking, landslides, liquefaction, and tsunamis'.
Youtube National Geographic.

For info, readings, videos and ideas on the causes and effects of volcanic eruptions:
Volcano world, showing current volcanic eruptions.
Youtube explanation.

For both:
Global change, with clickable maps to check where both earthquakes and volcanos are happening; the Mercalli intensity earthquake scale; and information on melt points of solid rock material.
Slideshare on living with earthquakes and volcanoes (remove the ad and click the up/down buttons to see the slideshow).

There is an overwhelming ton of stuff on earthquakes and volcanoes on the Internet. Find something you never knew before!

Monday 5 December 2011

Plate tectonics

First step, read Undersea mountains march into the abyss; watch the video, and pick up what information you can about plate tectonics.

Look carefully at the map on this BBC page which shows you the plate margins. This will help answer one of the challenges: to describe the distribution of earthquakes, volcanoes, and fold mountains in relation to plate margins.

Useful site to find locations: Internet geography. Map to see worldwide distribution of plate boundaries, earthquakes and volcanoes here.