Chapter 13 – Climate

Please add your comments about how to improve Chapter 13 here.

10 thoughts on “Chapter 13 – Climate”

  1. p. 427: I’m not sure of much evidence suggesting GIS or AIS volume loss at 300 ka (MIS 9), and would suggest just leaving it to 130 and 400 ka.

    p. 432: I don’t think “18O/16O works as a paleotemperature indicator because lower 18O/16O ratios are correlated with lower ocean water temperatures” really explains it. Instead, this part could be shifted a few sentences later after you say forams incorporate oxygen into their shells, and then explain that there is a fractionation/offset that depends on temperature.

    Figure 13.4: the d18O scale is incorrect. It looks like it’s for the marine record, rather than Antarctic ice cores (should be tens of per mil below zero).

    p. 435: “About a million years ago, something changed abruptly.” I don’t think there’s a consensus that the MPT was abrupt, and many would say it was a gradual transition over half a million years.

    p. 436: “A more elliptical orbit causes greater seasonality.” It causes both greater and lesser seasonality – e.g,. today the seasonality is decreased in the NH (perihelion in January) and increased in the SH. Better to just say that it modulates seasonality.

    p. 436-438, “Local Events – Global Effects”: The last two paragraphs seem to mix Heinrich and D/O events a bit. Rather than D/O events being associated with some Heinrich events, it’s the other way around. Also, an emerging consensus is that Heinrich events didn’t cause abrupt climate change, but rather may have been a response to it (they seem to lag AMOC slowdowns) and then fed back on it through freshwater input. Last, Heinrich events weren’t especially frequent when the Laurentide was intermediate in size and oscillating in the Great Lakes region – this is referring to the Clark et al 2001 meltwater routing hypothesis for D/O events shifting continental drainage around (different mechanism and time scale for freshwater input from the Heinrich IRD events).

    Figure 13.8: It’s a bit unclear what the inset image in the emergence curve graph is – a shell for dating? Might add a label to clarify.

    Figure 13.10: I find the “Local sea level” axes in these panels confusing/backwards, at least to my intuition. E.g., It shows local sea level shifting + for the Arctic site, but local sea level fell here as the land rebounded.

    p. 454: “Over the past 20 years…” It’s now been 30 years since Raymo 1988.

  2. Figure 13.14 pg. 451–should be split into two separate figures. The explanation for Cascade Mountains study is after the figure (on page 452), the figure would fit nicely here and would only require renumbering of the last figure in the chapter

  3. Figure 13.8 pg. 442–The photo on the emergence curve graph–what is this? Is this a piece of shell or wood? It is hard to tell, so stating what it is would provide relevance

  4. On page 454, last paragraph in the left column, Raymo’s uplift weathering hypothesis is described but not named. It would be helpful here if the name of the hypothesis was included. Students learn about this in other classes, and repetition always helps.

  5. The story of the Oso landslide would fit nicely into the Glacial-Interglacial changes section (pg 447)

  6. This chapter contains a lot of information about past the mechanisms of climate changes. The information about climate change records, timescale and causes summarized in pages 427-439 is almost excessive. I teach Earth’s Climate and it takes me an entire semester to teach the material that is presented in these 12 pages. In my geomorphology course, this content is covered at the end of the semester, when students are facing content overload, final projects, final exams… As climate is a primary control on landform and process, I am toying with the idea of only assigning the second half of this chapter so the students can glean the most important material in this chapter.

  7. Although it isn’t a typographical error, an awkward phrase that can be condensed is found on page 425. Rather than saying “the speed of the wind,” you could say “wind speed.”

    A figure showing relict calcic horizons would be helpful in understanding the changing ratio of precipitation and evaporation and also would be cool to see so that we could look for it in the field. This is mentioned on page 429. On page 429, the text boxes in figures13.3 and 13.4 have faint outline around them. Also figure 13.3 is a bit dark and blurry, making it difficult to see the indicated outwash terrace. The graph in figure 13.5 on page 435 has a unitless time axes. To understand the magnitude of the cooling event, units and numbers would be helpful.

    An end of concept question could be to define climate zones and the climates effect on geomorphology. For question 23, it would be helpful if you noted what the ELA was abbreviated from, equilibrium line elevation. The end of chapter questions for this chapter were very scattered – it would improve readability if they were ordered in accordance to when they showed up in the chapter.

    It was never mentioned what the actual climate effects of glacial melt in the North Atlantic. Although it mentions large sediment transport, it is never specified if the temperature or precipitation increases/decreases. (page 436). Also on page 439, there is a paragraph discussing El Nino events. After discussing characteristic events that accompany El Nino periods, there is a short section that begins with “In contrast, during El Nino years…” This does not make sense to me. Did you mean to say La Nina?

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