Key Concepts in Geomorphology – ideas for revision
Chapter 8 – Coastal
Please add your comments about how to improve Chapter 8 here.
17 thoughts on “Chapter 8 – Coastal”
recolor photo 8,3 so it’s not so green
Page 278 figure 8.12, the explanation box is confusing. The sentence is clunky and hard to decipher. I don’t think this is a good descriptor of how a submarine canyon is formed.
Page 263, Photograph 8.4 b needs a better, more thorough explanation. It shows many features that the author discussed – jetties, breakwaters, direction of drift and how you can see the transport, etc. There is sediment trapped between the breakwater and the shoreline plus it shows the erosion on the downdrift side. There’s a lot in this picture that is not discussed
Page 256. The diagram needs to be labeled a) b) c). Pic c (lower right) is confusing. What are you showing? Whatever it is, I don’t see it.
Figure 8.1 page 255 should be labeled differently. The top diagram is labeled “collisional margin” with the info box describing it as an “active” margin. The lower diagram is labeled “passive margin”. These should be comparable. If the author should call the upper diagram an “active margin” with the description of it being a collisional margin in the info box. The information in the boxes does not match. It should be labeled “Active vs. Passive Margins”. Did the author purposely leave out the other coastline classifications? There are different types of active and passive margins that have different morphologies.
Page 269, [Photograph 8.11]. “Ebb-tide deltas are generally small compared to flood-tide deltas because they are reworked by waves in the open marine environment and because the outgoing tide usually has a lower sediment-transport capacity than the incoming tide.” Yet this diagram shows a HUGE ebb tidal delta seaward. This is confusing because, according to the text, this should be a small delta. This needs a good pic of an ebb tidal delta (possibly in a lagoon behind a barrier island).
p. 254: ” After sea-level rise slowed enough that coastline locations stabilized, those estuaries and fjords that receive little sediment remain unfilled, even though they efficiently trap the sediment supplied to them. ” Again, grammar and a clunky sentence structure
Page 255: “The impact of postglacial sea-level rise on coastal geomorphology varies with time since deglaciation and with sediment supply. ” This sentence seems to be missing some words
page 254: “Emergent coastlines are stretches of the coast that have been exposed by relative sea-level fall.” This could also be the result of tectonic uplift. While it’s explained in the next paragraph, a student is going to get confused, i.e. why didn’t you say that initially? Just add “or tectonic uplift” to the sentence and then go on to explain it. This is the same with a submergent coast.
page 254: ” typically have a coastal mountain range hosting volcanoes and affected by earthquakes, ” Should this read ….hosting volcanoes and ARE affected by earthquakes? Although I don’t like the way that reads either. Maybe something like: “Subduction zones are the location of frequent, large, deep focus earthquakes that affect the coastal area.” This leads into the statement “Both types of subduction zone typically have a narrow continental shelf”. Subduction zoneS but….”both types”? What is the other type? Types of subduction zones are not discussed.
page 254: “Sea-level changes greatly affect coastal sediment dynamics. Estuaries, partly enclosed coastal water bodies fed by one or more rivers or streams, may form and enlarge when sea level rises, or they may diminish as when, for example, barrier islands erode away.” Barrier island erode away? This definitely needs to be explained. Estuaries don’t have barrier islands. Barrier islands are unique (in the US) to the east and gulf coast. I don’t understand the comparison between rising sea levels and eroding barrier islands. It seems very random.
Page 254: “A much smaller but potentially hazardous supply of sediment comes from wave erosion of the coastal margin”. Why/how is it hazardous? Is the process hazardous? The word “hazardous” either needs to be deleted or it needs to be explained.
Page 258, in discussing the destructive combination of spring tide and storm surge, a reference (and maybe a pic) to “Hurricane” Sandy would be good here. It hit at a spring high tide and destroyed a large part of the NY/NJ coastline
The intro discusses bathymetry but does not explain, nor show examples, of what it is and how it works. Students need to understand HOW we “see” the ocean floor through bathymetry
Move photograph 8.1. It’s out of place. There is no reference to it anywhere near it. It should be with the information on page 263
Adding an illustration for marine sedimentation (p. 276) could aid in understanding and break up the end of the chapter
In Figure 8.6 (262) adding to the longshore drift diagram and illustrating how longshore drift works along a meandering or cove-like shoreline could aid in understanding.
University of Vermont
recolor photo 8,3 so it’s not so green
Page 278 figure 8.12, the explanation box is confusing. The sentence is clunky and hard to decipher. I don’t think this is a good descriptor of how a submarine canyon is formed.
Page 263, Photograph 8.4 b needs a better, more thorough explanation. It shows many features that the author discussed – jetties, breakwaters, direction of drift and how you can see the transport, etc. There is sediment trapped between the breakwater and the shoreline plus it shows the erosion on the downdrift side. There’s a lot in this picture that is not discussed
Page 256. The diagram needs to be labeled a) b) c). Pic c (lower right) is confusing. What are you showing? Whatever it is, I don’t see it.
Figure 8.1 page 255 should be labeled differently. The top diagram is labeled “collisional margin” with the info box describing it as an “active” margin. The lower diagram is labeled “passive margin”. These should be comparable. If the author should call the upper diagram an “active margin” with the description of it being a collisional margin in the info box. The information in the boxes does not match. It should be labeled “Active vs. Passive Margins”. Did the author purposely leave out the other coastline classifications? There are different types of active and passive margins that have different morphologies.
Page 269, [Photograph 8.11]. “Ebb-tide deltas are generally small compared to flood-tide deltas because they are reworked by waves in the open marine environment and because the outgoing tide usually has a lower sediment-transport capacity than the incoming tide.” Yet this diagram shows a HUGE ebb tidal delta seaward. This is confusing because, according to the text, this should be a small delta. This needs a good pic of an ebb tidal delta (possibly in a lagoon behind a barrier island).
p. 254: ” After sea-level rise slowed enough that coastline locations stabilized, those estuaries and fjords that receive little sediment remain unfilled, even though they efficiently trap the sediment supplied to them. ” Again, grammar and a clunky sentence structure
Page 255: “The impact of postglacial sea-level rise on coastal geomorphology varies with time since deglaciation and with sediment supply. ” This sentence seems to be missing some words
page 254: “Emergent coastlines are stretches of the coast that have been exposed by relative sea-level fall.” This could also be the result of tectonic uplift. While it’s explained in the next paragraph, a student is going to get confused, i.e. why didn’t you say that initially? Just add “or tectonic uplift” to the sentence and then go on to explain it. This is the same with a submergent coast.
page 254: ” typically have a coastal mountain range hosting volcanoes and affected by earthquakes, ” Should this read ….hosting volcanoes and ARE affected by earthquakes? Although I don’t like the way that reads either. Maybe something like: “Subduction zones are the location of frequent, large, deep focus earthquakes that affect the coastal area.” This leads into the statement “Both types of subduction zone typically have a narrow continental shelf”. Subduction zoneS but….”both types”? What is the other type? Types of subduction zones are not discussed.
page 254: “Sea-level changes greatly affect coastal sediment dynamics. Estuaries, partly enclosed coastal water bodies fed by one or more rivers or streams, may form and enlarge when sea level rises, or they may diminish as when, for example, barrier islands erode away.” Barrier island erode away? This definitely needs to be explained. Estuaries don’t have barrier islands. Barrier islands are unique (in the US) to the east and gulf coast. I don’t understand the comparison between rising sea levels and eroding barrier islands. It seems very random.
Page 254: “A much smaller but potentially hazardous supply of sediment comes from wave erosion of the coastal margin”. Why/how is it hazardous? Is the process hazardous? The word “hazardous” either needs to be deleted or it needs to be explained.
Page 258, in discussing the destructive combination of spring tide and storm surge, a reference (and maybe a pic) to “Hurricane” Sandy would be good here. It hit at a spring high tide and destroyed a large part of the NY/NJ coastline
The intro discusses bathymetry but does not explain, nor show examples, of what it is and how it works. Students need to understand HOW we “see” the ocean floor through bathymetry
Move photograph 8.1. It’s out of place. There is no reference to it anywhere near it. It should be with the information on page 263
Adding an illustration for marine sedimentation (p. 276) could aid in understanding and break up the end of the chapter
In Figure 8.6 (262) adding to the longshore drift diagram and illustrating how longshore drift works along a meandering or cove-like shoreline could aid in understanding.