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Posts tagged Southern Alps

Climate Change’s Potential Effects on New Zealand

44S 170.1E

April 2nd, 2013 Category: Climate Change

New Zealand – April 2nd, 2013

Human activity is increasing the natural level of greenhouse gases in the atmosphere causing Earth to warm up and the climate to change. The effects of a warming planet and disrupted climate pattern are already becoming evident.

In New Zealand likely climate change impacts include: higher temperatures, more in the North Island than the South, (but still likely to be less than the global average), rising sea levels, more frequent extreme weather events such as droughts (especially in the east of New Zealand) and floods, as well as a change in rainfall patterns – higher rainfall in the west and less in the east.

These changes will result in both positive and negative effects. For example: agricultural productivity is expected to increase in some areas but there is the risk of drought and spreading pests and diseases. Forests and vegetation may grow faster, but native ecosystems could be invaded by exotic species. Drier conditions in some areas are likely to be coupled with the risk of more frequent extreme events such as floods, droughts and storms.

Rising sea levels will increase the risk of erosion and saltwater intrusion, increasing the need for coastal protection. Also, snowlines and glaciers are expected to retreat and change water flows in major South Island rivers, such as those visible in this image, flowing down from the Southern Alps and glacial lakes (click here for more details).

Glacial Lakes Amongst Southern Alps of New Zealand

44.8S 169.2E

February 27th, 2013 Category: Climate Change, Lakes, Mountains

New Zealand – February 26th, 2013

Glacial lakes can be seen here, nestled amidst the peaks of New Zealand’s Southern Alps. Scientists have found that hundreds of steep mountain glaciers, which rapidly pass their ice gains down to their termini, have all fluctuated in size due to climate change over the last 35 years. Between 1976 and 2005 the volume decreased more than 10%, from 54.60 km3 to 48.74 km3. More than 92% of this loss was from 12 of the largest glaciers.

For the big glaciers, glacial lakes have begun to form at their fronts as lowering ice levels reach the level of their outlet rivers. Once a lake has formed, it eats at the glacier far faster than surface melt. At the front of the glacier, the ice cliff calves bergs into the lake. This positive feedback ensures a massive and catastrophic depletion of the glacier volume, creating an irreversible tipping-point for the glacier. It would take an ice age climate to drive the glacier back across the lake and to reverse the process (click here for more information).

Vegetation Index of New Zealand’s North and South Islands

41.2S 173.3E

June 21st, 2012 Category: Vegetation Index

New Zealand - January 3rd, 2012

This FAPAR image shows the vegetation index of New Zealand’s North and South Islands. The index of photosynthetic activity is mostly mixed between good (green) and high (rusty red) on both islands, although there is a larger area of an exclusively high index on the North Island. Levels of activity are lowest by the Southern Alps, the mountainous backbone of the South Island.

Southern Alps and Stewart Island / Rakiura, New Zealand

46.9S 167.8E

February 24th, 2012 Category: Mountains

New Zealand - January 8th, 2012

New Zealand’s Southern Alps are mostly snow free in this late summer image of the southern part of the country’s South Island. Visible by the mountains are several glacial lakes. Off the southern coast is Stewart Island/Rakiura, the third-largest island of New Zealand. It lies 30 kilometres (19 mi) south of the South Island, across Foveaux Strait.

This hilly island with a wet climate has an area of 1 746 km². The north is dominated by the swampy valley of the Freshwater River. The river rises close to the northwestern coast and flows southeastwards into the large indentation of Paterson Inlet. The highest peak is Mount Anglem (979 metres (3,212 ft)), close to the northern coast it is one of a rim of ridges that surround Freshwater Valley. The southern half is more uniformly undulating, rising to a ridge that runs south from the valley of the Rakeahua River.

Vegetation Index of New Zealand Highest Near Southern Coast

45.3S 168.0E

January 19th, 2012 Category: Vegetation Index

New Zealand - December 30th, 2011

This FAPAR image shows the vegetation index of the southern half of New Zealand’s South Island. The index is highest (rusty red) in the coastal plains by the southern shores, and lowest (yellow) amidst the ridges of the Southern Alps.

Many fjords can be observed along the southwestern coast, as can several glacial lakes in the mountains towards the center of the island (Southern Alps). A faint phytoplankton bloom can be observed off the east coast.