# **Introduction** Aoraki Mt. Cook National Park is located in the Canterbury region of New Zealand, nestled within the Southern Alps. Aoraki is New Zealand’s tallest mountain and is a place of great cultural significance for the indigenous Māori people. Hooker Glacier can be found within Aoraki Mt. Cook NP, and is the focal point of today’s expedition; within this one photo experience, you will learn about several different glacially-created geological formations, and gain a better understanding of the power of glaciers. Below you will find the highlights of this field trip: * Glacial retreat * Proglacial lakes * Hanging valleys * Alluvial fans * Holocene moraines * Talus cones If you are interested in learning more about glacier terminology, you can visit USGS’s [Glossary of Glacier Terminology](https://pubs.usgs.gov/of/2004/1216/text.html). If you would like to explore the park outside of this lesson, you can find it pinned on [Google Maps](https://goo.gl/maps/PnegBfpKvVmwvQBi6). ## **Māori Culture** Aoraki is considered the origin of what is now the Southern Alps mountain range of New Zealand's South Island. Rich Māori cosmology, found[ here](https://www.hermitage.co.nz/our-culture/#:~:text=Aoraki%20was%20the%20son%20of,became%20hungry%20and%20began%20fishing.), describes how Aoraki and the neighboring mountains came to be. They are considered the ancestors of the Māori, so it is considered disrespectful to summit Aoraki since that would be stepping on the head of an ancestor. ## **Glaciology** As previously mentioned, New Zealand's geography has been drastically affected by the presence of glaciers. Glaciers are unique in that they create curved, U-shaped valleys as they erode the landscape. In many cases, this occurs over a previously-established v-shaped valley, which occurs when streams (not glaciers) cut through the land. The company of such majestic land features has driven many tourists to the small island nation. Helicopter tours, guided hiking, and many other outdoor experiences are linked with glaciers, and otherwise secluded villages and towns have come to expect an influx of tourists each year. Although glacial advance and retreat are natural phenomena, scientists have found most glaciers to be retreating at unprecedented rates for the last several decades due to climate change. Where does that leave New Zealand? Not only are glaciers a quintessential part of the nation’s identity, but they play a role in the national economy that cannot readily be replaced. Melt from Hooker Glacier, when it travels downstream, is utilized for hydropower, which makes it even more valuable to preserve the glacier for infrastructure purposes. Physical changes in the appearance of Hooker Glacier can be observed below. ![image.png](https://lh4.googleusercontent.com/A-CUGqGfpY93tSAwlbqMODotBNIMzbmTWmQj8arocGfqtxiYFnzlx8EjMyEoPDqHGWSC8XqXPPjKf779PWT3CnizF6N_hceB-eJqX0igwqchlPM2WRputVF3UHV0lxpNvgH1CIHTbpDyGXV7ec2rJzk) Source:[ American Geophysical Union](https://blogs.agu.org/fromaglaciersperspective/2016/01/11/hooker-glacier-retreat-1991-2015/) ## **Guiding Questions** * What direction has the Hooker Glacier retreated toward? * How do glaciers shape valleys? * What gives glacial lakes their color? * Find some examples of depositional landscape features. * Find some examples of erosional features. Answers for the questions above can be found [here](https://docs.google.com/document/d/12CnGEjHnFDFPpv6v5ksrB9L9ko5N_h7PjYwlxSbEOzA/edit?usp=sharing). **[Enter VR](/scenes/aoraki-hooker-valley)** **![](https://lh4.googleusercontent.com/K8Gj8VSTy5QGJThNM2pYdHnRSHMgZDB8b2oOLgSzmpI55LRCsu67I-QC1QJdXgvSaIb_A-wiGXZDBOrHTTxpDoNAW-wSfWZh_CVIVSPAWwerz0JJWwk32l31bfxXDIPJeomzXxA1GH3KNS83A8XelZM)** **Legend:** 1. Debris (Talus) Cone 2. Valley Glacier Terminus 3. Rock Flour 4. Alluvial Fan 5. Hanging Valley 6. Proglacial Lake 7. Moraine 8. Holocene Epoch ## **Glossary** Unless otherwise linked, all definitions come from USGS’s [Glossary of Glacier Terminology](https://pubs.usgs.gov/of/2004/1216/text.html). [Alluvial Fan](https://www.usgs.gov/news/science-snippet/earthword-alluvial-fan): this happens when a fast-moving mountain stream empties out onto a relatively flat plain. All of the sediment it was carrying falls out as the water slows down. Aoraki: The tallest mountain in New Zealand’s Southern Alps, which holds great cultural and historical significance for the Māori people. Debris (Talus) cone: A cone or mound of debris-covered ice, with a thick enough sediment cover to protect the ice from melting. Depositional: Sediments left at a site originating from erosion, and may have come from other land features. Erosional: Sediments on a site that were made loose by erosion. Glacial advance: An increase in the length of a glacier compared to a previous point in time. As ice in a glacier is always moving forward, a glacier's terminus advances when less ice is lost due to melting and/or calving than the amount of yearly advance. Glacial retreat: A decrease in the length of a glacier compared to a previous point in time. As ice in a glacier is always moving forward, its terminus retreats when more ice is lost at the terminus to melting and/or calving than reaches the terminus. During retreat, ice in a glacier does not move back up the valley. Hanging valley: A former tributary glacier valley that is incised into the upper part of a U-shaped glacier valley, higher than the floor of the main valley. Holocene: The current part of geologic time. The Holocene epoch began \~12,000 years ago, at the end of the Pleistocene epoch. [Māori](https://maoridictionary.co.nz/search?keywords=maori): Indigenous New Zealander; an indigenous person of Aotearoa/New Zealand - a new use of the word resulting from European contact in order to distinguish between people of Māori descent and the colonizers. Moraine: A general term for unstratified and unsorted deposits of sediment that form through the direct action of, or contact with, glacier ice. Proglacial lake: a lake that is located adjacent to the terminus of a glacier. Rock flour: Fine-grained, silt-size sediment formed by the mechanical erosion of bedrock at the base and sides of a glacier by moving ice. Terminus: The lower-most margin, end, or extremity of a glacier. U-Shaped valley: A valley with a parabolic or "U" shaped cross-section, steep walls and generally a broad and flat floor. Formed by glacier erosion, a U-shaped valley results when a glacier widens and over-steepens a V-shaped stream valley. Valley glacier: A glacier that flows for all or most of its length within the walls of a mountain valley. ## **Sources** Purdie, Heather. “Glacier Retreat and Tourism: Insights from New Zealand.” Mountain Research and Development 33.4 (2013): 463 – 472. [https://bioone.org/journals/mountain-research-and-development/volume-33/issue-4/MRD-JOURNAL-D-12-00073.1/Glacier-Retreat-and-Tourism-Insights-from-New-Zealand/10.1659/MRD-JOURNAL-D-12-00073.1.full](https://bioone.org/journals/mountain-research-and-development/volume-33/issue-4/MRD-JOURNAL-D-12-00073.1/Glacier-Retreat-and-Tourism-Insights-from-New-Zealand/10.1659/MRD-JOURNAL-D-12-00073.1.full)