Lecture'17'Questions'

Lecture'17'Questions' 1.#How#did#salt#end#up#in#our#Oceans?# a)#Salt#was#always#present#in#Oceans.# # # # b)#Precipitation#falling#into#the#Ocean#contains#salt.# # # # c)#Volcanoes#let#out#salt#when#they#erupt.# # # # d)#Rain,#rivers#and#streams#transport#salt#into#the#Ocean#from#chemical#dissolution#of# rocks.# # # e)#None#of#the#above.# # 2.# If# you# followed# a# single# drop# of# water# during# a# passing# wave,# in# which# motion# would#it#move?# a)#Forward# b)#Vertical#circle# c)#Horizontal#circle# d)#Irregular# e)#Backward# # 3.#If#the#velocity#and#period#of#a#wave#are#doubled#at#the#same#time,#the#wavelength# will#be#_______#times#of#the#original#one.# a)#2# b)#4.# c)#1/2# d)#1/4# # e)#1.# # # 4.#The#storm#surge#associated#with#a#hurricane#is#created#by# a)#low#atmospheric#pressure# # b)#winds#circling#the#eye#of#storm# # c)#tides#and#waves# # d)#both#a#and#b# # e)#both#b#and#c# # 5.#Water#waves#can#store#or#dissipate#much#energy.#So#theoretically#a#3m#high#wave# has#___#times#more#energy#than#a#1m#high#wave#(assuming#Tp#values#are#the#same).# # a) 3# b) 6# c) 9# d) 0.57# e) 1# # # #

6.' A' girl' sitting' on' a' beach' counts' 6' wave' crests' pass' a' buoy' in' 3' seconds.' She' measured' the' distance' between' the' wave' crests' to' be' 1.5m.' ' What' is' the' frequency' of' the' waves' in' hertz?' ' What' is' the' speed' of' the' waves' the' girl' observed?' Frequency = # waves / time frequency ' = 6 waves / 3s ' = 2 Hz ' ' Wave speed = wavelength x frequency wave speed ' = 1.5m x 2 Hz ' = 3 m/s ' ' 7.'Describe'how'Oceans'alter'weather'at'the'local'scale?' # # The water in the ocean stores heat. When the temperature is lower on # land, the heat transfers to the land and vice versa - so spring is late and ' fall is longer. ' ' Oceans also act as a source of local precipitation. ' ' 8.'Give'three'reasons'why'tsunamis'have'smaller'energy'than'wind'waves'but'they' are'much'more'destructive'than'wind'waves?' # 1) Tsunamis have long wavelengths. They are much more destructive than normal waves because the huge flooding body of water can continue to rush onto land for an extended period of time. This may be anything from a few minutes up to an hour, compared to # seconds for wind-driven waves. # 2) As a tsunami # approaches land, the size increases. As the wave approaches land it reaches shallow water and slows down. Relative to the front of the wave, the rear is still in slightly deeper water (so it is going slightly faster) and catches up. The result is that the wave ' quickly 'bunches up', the wavelength becomes shorter and the body of water becomes much higher. This is called shoaling. ' 3) Tsunamis are ' fast. A tsunami can travel at well over 970 km/hr (600 mph) in the open ocean - as fast as a jet flies. It can take only a few hours for a tsunami to travel across an entire ocean. A regular wave (generated by the wind) travels at up to about 90 km/hr. ' 9)'List'three'potential'destructive'impacts'of'living'in'lowKlying'coastal'areas' # 1) Flooding and coastal erosion which will result in the loss of coastal infrastructure # (including breakwaters, roads, public coastal amenities), habitat and ecosystem goods # and services. ' 2) Sea ' level rise could result in low-lying coastal areas, i.e. coastal flood plains, becoming inundated, with a resultant impact on coastal settlements. ' ' 3) Vulnerability along the coast is set to increase with increased frequency and intensity of ' coastal storms. ' 10)'What'are'the'warning'signs'of'a'tsunami?' 1). A' shaking of the ground in coastal regions may reflect the occurence of a large undersea earthquake nearby that may generate a tsunami.

2). As a tsunami approaches shorelines, the sea may withdraw from the beach (like a very low and fast tide) before returning as a fast-moving tsunami. 3). A roaring sound may precede the arrival of a tsunami