An Earthquake, a Landslide and Two Glaciers in New Zealand

Glaciers can play an important role in landscape dynamics, interacting with other factors to shape landscape development. Two days after a 7.8 magnitude earthquake struck North Canterbury, New Zealand, a landslide occurred between nearby Fox and Franz Josef glaciers. This landslide could offer insight into the role of glaciers in seismically active areas, particularly concerning the ways in which glaciers interact with earthquake-related instabilities in the landscape.

The landslide occurred at Omoeroa at around 2 p.m. (GMT +12 hours) on November 16th, closing off a section of State Highway 6 along the west coast of South Island for about three hours until debris were cleared.

Earthquakes and landslides are common in New Zealand due to the country’s location on the Pacific Ring of Fire, the area around the Pacific Ocean that is very seismically active. It is so named because of the prevalence of volcanic activity within the ring, which is made up by the major tectonic plate boundaries.

Types of faults based on the movement of rocks (Source: USGS/Wikimedia Commons)
Types of faults based on the movement of rocks (Source: USGS/Creative Commons).

Earthquakes, which occur when Earth’s crust breaks along faults (fractures in the crust), send tremors outwards from the point of breakage. This particular earthquake was caused by oblique-reverse faulting (faulting that had both strike-slip and reverse components) near the boundary of the Pacific and Australian tectonic plates. Landslides, like the one that occurred between the two glaciers, are often triggered by other natural disasters, such as earthquakes or floods. In this case, the earthquake and its aftershocks triggered up to 100,000 landslides, causing local damage and blocking major roads and railway routes.

In conversation with GlacierHub, Umesh Haritashya, an associate professor in environmental geology at the University of Dayton, explained that the region in which the landslide occurred is prone to landslides even without any seismic activity. This is due to the topography of New Zealand’s Southern Alps. As such, it would not be surprising if the earthquake, landslide and glaciers are connected, he said.

While the two glaciers are found on the west coast of South Island, the earthquake occurred on the east coast of the island. The distance between the two suggests that the intensity of the tremors experienced in the area around the landslide may have been quite low. Nonetheless, a link is possible, according to Jeff Kargel, a geoscientist at the University of Arizona. “The timing of this big landslide is certainly suggestive of a direct link to the earthquake,” Kargel told GlacierHub.

The terminus of Fox glacier in 2013, showing the surrounding mountain topography (Source: Umesh Haritashya)
The terminus of Fox glacier in 2013, showing the surrounding mountain topography (Source: Umesh Haritashya).

“For both direct and circumstantial reasons, earthquakes, glaciers and landslides are closely associated,” Kargel explained. “There is the direct influence of glaciers that produce lots of unstable rock debris over thousands of years, and there are indirect influences, where glaciers erode the mountain topography and produce very steep slopes. These factors create conditions under which seismic activity can easily set off landslides.”

In addition, Kargel noted that glaciers occur where uplift rates have been high and the terrain is elevated to begin with. This means that either circumstantially or indirectly, glaciers and landslides can occur nearby.

Kargel further stated that large earthquakes tend to create instabilities in the landscape that are later exploited by natural processes, making landslides more frequent in the aftermath of earthquakes. “The spike in landslide activity can last for several years,” he said.

The terminus of Franz Josef Glacier, as seen in 2006 (Source: Sarah Toh)
The terminus of Franz Josef Glacier, as seen in 2006 (Source: Sarah Toh).

In addition to seismic activity, other causes like heavy rain after the earthquake could have contributed to the occurrence of the landslide. New Zealand’s MetService reported that the areas of the glaciers had received considerable rain, with 80-120mm falling the night after the earthquake.

“The West Coast receives an unusually high amount of rain, so slopes are already reconditioned and any seismic activity can trigger major landslides,” Haritashya explained.

The links between the earthquake, glaciers and landslides will become clearer as scientists examine similar events more fully. For now, landslides like these offer an insight into the complex interactions between glaciers, topography and seismic activity. Earthquakes can cause large amounts of disruption to people’s lives, so advancements in this field of science could prove valuable to communities as they seek to address the challenges posed by natural disasters.

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As Glaciers Melt, Tourists Keep on Coming to New Zealand

While more people are visiting iconic New Zealand glaciers because of concerns that climate change might wipe out the ice masses altogether, visitors are reportedly underwhelmed by the melting, gray glaciers. 

This finding is documented in a new multidisciplinary study, “Implications of climate change for glacier tourism,” released last month in Tourism Geographies. The findings were published by Emma J. Stewart and researchers at Lincoln University, in Canterbury, New Zealand, in conjunction with others from neighboring and international universities. The study examines the impacts of climate change on the Fox and Franz Josef Glaciers in New Zealand’s South Island, and how these effects have trickled down to local tourism. The tourism industry there collectively attracted over 500,000 international visitors in 2015.

Westland Tai Poutini National Park
Westland Tai Poutini National Park, with neighboring Fox and Franz Josef Glaciers. (Photo courtesy of Tourism Geographies.)

These glaciers, located in Westland Tai Poutini National Park, are just two of New Zealand’s more than 3,100 glaciers, but they are the country’s most beloved and visited, and have received a flow of tourists dating back to the early 1900s. Their distinctive morphology creates glacier tongues that flow down from the high mountains to low, visitor-accessible elevations.

However, studies show that glacier recession has accelerated at an unprecedented rate in New Zealand. Previous studies estimate that Fox Glacier lost over 700 meters in length between 2008 and 2015, and that neighboring Franz Josef Glacier experienced a similar rate of reduction. Recent modeling estimates that Franz Josef Glacier will shed 62 percent of its current volume by 2100.

Fox Glacier
Changes in surface debris cover (black regions) on Fox Glacier from 2008 to 2014. (Photo courtesy Tourism Geographies.)

In order to explore perceptions of change with regard to glaciers and tourism, the researchers conducted 13 stakeholder interviews with employees from the New Zealand Department of Conservation (DOC) and commercial tourism businesses at the two glaciers. They also administered questionnaires to 500 English-speaking visitors who were returning from guided walks to view Fox or Franz Josef Glacier. Researchers asked visitors about their reasons for journeying to the sites and their overall satisfaction with their glacier visit.

Stakeholders showed widespread agreement that the region’s glacier tourism industry was largely inspired by visitor perceptions of the glaciers as a “bucket list” item or as a “last chance” tourism trip. The notion of “last chance” glacial tourism encapsulates visitors’ desires to observe, photograph, or interact with threatened or rare physical features and natural landmarks. The study suggests that New Zealand’s high levels of glacier tourism are largely due to visitors’ desire to visit these iconic natural landmarks before they disappear.

The study also reveals that stakeholders and tourists alike perceive the glaciers as highly significant to the region and to New Zealand.

“The glaciers are first and foremost the reason why people stop at Franz and Fox,” a DOC employee stressed. 

A Franz Josef tourism manager echoed these sentiments, telling his interviewers, “If the glaciers were not here, these towns would not be either.”

“[The glaciers] are hugely significant to New Zealand – culturally, naturally and economically. They are icon destinations on the South Island,” one of the study’s two lead researchers, Emma Stewart of Lincoln University, told GlacierHub in an email.

Yet while stakeholders are in widespread agreement of the glaciers’ importance to the region, and the time-sensitive nature of the possibilities of visiting them, the study’s interviews reveal that visitors are also expressing less wonder at the sight of the once majestic glaciers.

In the survey, one DOC ranger said, “I would feel much better if the glaciers were coming forward, they always look better, whereas now it’s just a dirty old strip of ice up around the corner.”

The study noted that “significant segments of the visitor population” found that their expectation of the size and condition of the glaciers “exceeded the reality.”

Fox Glacier
Lower part of Fox Glacier with glacier tongue in February 2013. (Photo courtesy Matthias Basler.)

On average, 50 percent of interviewed visitors expected the glacier to be “bigger,” 45 percent expected the ice would be “cleaner” and 35 percent thought the glacier would be “more spectacular.” The surveyors noticed that visitor satisfaction often correlated with how high up on the glacier the visitors travel.  

The glaciers’ rapid retreats and the resulting increased risk of rockfall hazards have impeded visitor access, particularly higher up on the glacier, and especially on Franz Josef.

Co-author Heather Purdie of the University of Canterbury told GlacierHub via email that guided walks to Franz Josef recently were suspended.

“Guided walks that used to access the glaciers on foot from the lower valley are now no longer possible,” she wrote.

She notes that now, visitors can only participate in a guided walk tour by flying to the glaciers by helicopter. This option’s high price is prohibitive for many visitors, though.

Overall, access is becoming limited. “People cannot get as close to the glacier as they used to,” Purdie continued. 

These findings highlight concerns that glacial tourism may decrease with increased glacial melting. One accommodation provider suggested that, “If the glaciers are established enough as a tourist icon then people will come even if it is not like it used to be.” However, the provider then added, “Maybe I am naïve to think that people will still come here without the glacier.”  

Yet the study simultaneously argues that perceptions of the “last chance to see” phenomenon of glaciers might simultaneously increase glacial tourism in the region.

The study is the first of its kind to report highly adaptive capacities of glacial tourism stakeholders, such as DOC employees and glacial tourism companies. Among the stakeholders interviewed, the study reported strong evidence of the understanding of biophysical trends and a demonstrated ability to flexibly and successfully facilitate glacial access and glacier product availability and to maintain high levels of visitor satisfaction, by actions such as introducing helicopter rides to survey the glacier and modifying walking tour routes to increase safety and better showcase the glacier as it melts.  

The authors hope that Westland Tai Poutini National Park’s case-specific adaptive strategies to adapt their glacial tourism sectors to climate change can extend beyond New Zealand. 

“Given that glaciers are retreating globally,” Stewart said.  “[The study] has implications for more local, and possibly neighboring glacier experiences, such as the Tasman and Hooker Glaciers in the Aoraki/Mount Cook National Park.”

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