River Severn Esturary

Question 1

what is an estuary

Answer 1

the tidal mouth of a large river, where the tide meets the stream

Question 2

estuary formation

Answer 2

large river like severn enters sea at narrow mouth
after ice age, melting ice rises sea level
low lying valley sides flood
original channel of river is now on estuary floor
where it provides a deep channel for shipping

Question 3

4 characteristics of an estuary

Answer 3

high tidal range (severn is 15m)
very wide (severn is 3.2km)
mudfloats visible at low tides
tidal bores that occur 25 days a year (8 to 21kmph)

Question 4

keywords and what they mean

Answer 4

tidal bore - huge waves that funnel up river
mudfloats - small streams of mud
marine processes - process that happens in salt water
salt marsh - when mudfloats become colonised

Question 5

how are mudflats formed

Answer 5

form in sheltered areas where tidal water flows slowly
river transports alluvium to sea
incoming tide transports sand and marine silt up estuary
river and sea mix (water and salt water)
velocity reduces and deposits silt
build up layers of mud make mudfloats