When considering the risks posed to Antarctica HSMs by the impacts of climate change, there are several factors to be considered as part of a desk-based assessment.
Materiality
Question
Is the HSM comprised of durable materials?
Some HSMs have complex materiality. The expedition bases of early Antarctic scientists and explorers are examples of complex sites containing a variety of durable and non-durable materials. For this reason, it is important to consider the values of the site as part of the assessment. If the valued parts of the HSM are made from, or contain non-durable materials (e.g., wood, paper, leather, textile, etc.), then the desk-based assessment should be based on these parts.
Use the following table of materials as a guide (Table 1). A score of six or higher indicates non-durable materials for the purpose of the risk assessment:
Table 1 – Some common cultural materials and their relative durability.
| Durability | Cultural Material | Frozen & Stable State | Thawed & Stable State | Subject to Freeze-Thaw Cycle |
|---|---|---|---|---|
| 1 (Most durable) | Hard Stone, Thick Glass, Noble Metals | 1 | 1 | 2 |
| 2 | Thick Metals, Concrete | 2 | 2 | 3 |
| 3 | Glass, Ceramics, Soft Stone, Coal, Mortar | 3 | 3 | 5 |
| 4 | Stable (Less-volatile) Chemicals, Oil, Grease | 4 | 4 | 4 |
| 5 | Thin Metals, Cans/Tins, Hardwood | 5 | 5 | 6 |
| 6 | Softwood, Rubber, Plastics, Paint | 6 | 6 | 8 |
| 7 | Fuel, Wax | 7 | 10 | 10 |
| 8 | Textiles, Paper, Blubber, Less Noble Metals | 8 | 9 | 8 |
| 9 | Bone, Ivory, Antler, Tawed Leather, Animal Feed | 9 | 10 | 8 |
| 10 (Least durable) | Untanned Leather, Furs, Foodstuffs, Volatile Chemicals | 10 | 10 | 10 |
Example 1 - HSM No 2 , Fukishima’s Rock Cairn, consists of a bronze plaque affixed to a rock cairn hardened with concrete. These are robust and durable materials in the context of likely climate change impacts.
Example 2 - HSM No 2 , Observation Hill Cross, consists of hardwood planks, laminated together with bronze dowels, secured in a concrete footing. While concrete and bronze are durable materials, wood is less durable. Because the cross is made from wood it should be regarded as non-durable in the context of likely climate change impacts.
Continental context
Question
Is the HSM located in the Western Antarctic (i.e., west of the Transantarctic Mountains)?
This coarse data input is intended to reflect the asymmetric warming taking place in eastern and western Antarctica
Example 1 - HSM No 77 , Cape Denison, is located in George V Land east of the Transantarctic Mountains.
Example 2 - HSM No 79 , Lillie Marleen Hut, is located in Northern Victoria Land west of the Transantarctic Mountains.
Regional context
Question
Is the HSM located on the Antarctic Peninsula, South Orkney Islands, or South Shetland Islands?
These parts of Western Antarctica are experiencing the highest temperatures.
Example 1 - HSM No 84 , Hut at Damoy Point, is located on Wiencke Island of the Palmer Archipelago, Antarctic Peninsula Region.
Example 2 - HSM No 43 , Belgrano Station’s Cross, is located in Coats Land and not part of the Antarctic Peninsula, South Orkney Islands, and South Shetland Islands.
Proximity to water
Question
Is the HSM located at a coastal site?
The intention is to distinguish HSMs which are in marine environments.
Example 1 - HSM No 87 , Commemorative plaque at the location of the first permanently occupied German research station in Antarctica, is located at 70°46′39″ S, 11°51′3″ E in the Schirmacher Oasis. This is an inland/interior site.
Example 2 - HSM No 42 , Laurie Island Observatories, located at 60°44′18″ S, 44°44′19″ W in the South Orkney Islands, is a coastal site where the values of the HSM are situated near the shoreline.
Elevation above mean sea level (MSL)
Question
Is the HSM located 3m or less above sea level?
The distinction of 3m is somewhat arbitrary but intended to reflect both the vulnerability of a site to storm surges, coastal reshaping, plus the combined impacts of ocean thermal expansion and glacial melting described in Chapter 13 of IPCC AR5 report (i.e., the risk includes but is not limited to the threat of SLR).
Example 1 - HSM No 23 , Grave of Nicolai Hanson, is located at approximately 350m above MSL.
Example 2 - HSM No 22 , Borchgrevink's 'Southern Cross' Hut, is located approximately 2.5m above MSL.
Proximity to shoreline
Question
Is the HSM located within 100m of shoreline?
Sites located within 100m of shoreline are vulnerable to sea-spray, storm surges, coastal reshaping, and SLR.
Example 1 - HSM No 71 , Whalers Bay, Deception Island is a complex site where most of the cultural values are situated within 100 meters of shoreline.
Example 2 - HSM No 85 , The plaque commemorating the PM-3A Nuclear Power Plant at McMurdo Station is located more than 100 meters from shoreline.
Steep slopes
Question
Does the HSM site have steep slopes (i.e., greater than 20%)?
Thawed soils containing sand and gravel will typically find an angle of repose between 25-30 degrees. Sites containing steep slopes and permafrost become highly active when they thaw.
Example 1 - HSM No 19 , Vince's Cross, is situated on a steeply sloped ridge at Hut Point Peninsula.
Example 2 - HSM No 39 , Hope Bay stone hut, is situated on a gently sloping beach at Trinity Peninsula.
Presence of permafrost
Question
Is the HSM situated on permafrost soils?
There are multiple threats associated with permafrost, especially at coastal sites where the presence of permafrost increases the risk of coastal reshaping.
Example 1 - HSM No 67 , Granite House, is situated on bedrock.
Example 2 - HSM No 18 , Scott's 'Discovery' Hut, is situated on permafrost soils.