Where would Christchurch be 100 million years in the past? 100 million years in the future?

To begin, let's look at Christchurch, New Zealand 100 million years in the past. According to this map, the entire island of New Zealand is in the polar region. It is also much closer to larger land masses. This would have huge effects on the climate. The area would receive little to no precipitation and the annual temperatures would drop over 40 degrees Celsius. Also, the temperature variation of the seasons would increase from an average of 15 degrees Celsius to an average of 40 degrees Celsius. This would happen because the climate of the island would not be controlled by the ocean like it is today. This region would only be influenced by polar continental air masses. The ocean would still have an impact but there are no warm currents near the south pole. A climograph for this location at this time would look something like this...



 A climograph of Christchurch so a much smaller diurnal temperature variation as well as much high rainfall levels given that is is now a maritime climate, instead of polar.

  Now, take a look at where Christchurch would be 100 million years in the future. This map is based on continental drifts from the past and estimations of where it would lead in the future. This is also based on the assumption that Earth will still exist that far into the future. As you can see, this map predicts New Zealand will move so far north that is will be cut in half by the Equator. This would also shift the climate drastically. With much warmer water surrounding the island, rainfall levels would nearly quadruple. Moving closer to large land masses would also assist in the rise of rainfall. Being this close to the equator and receiving this much rainfall would contribute greatly to the reduction in variation of diurnal temperatures in the area. The humidity would skyrocket; not that it's low currently, but it would be significant. Given higher rainfalls and steady temperatures, a climograph of the regions future would look similar to the one below...

Christchurch, and New Zealand in general, has made and will make some very significant travels in its time. It managed to make is from the south pole, up to the mid-latitudes of the southern hemisphere, and will just make it to the northern hemisphere. It is a place that will experience several climates throughout its time; except continental. This island seperated from the pack and will not rejoin a continent for a minimum of 100 million years. 

Reflection #2 - Christchurch, New Zealand vs. Ranohira, Madagascar

I chose Ranohira, Madagascar because it is similar in ways to Christchurch, but very different. Both locations are on a large island off the west coast of a large continent in the Southern Hemisphere. Ranohira differs in three major ways: 1 - it is much closer to Africa than New Zealand is to Australia, 2 - it is about 20 degrees closer to the equator than Christchurch,  3 - it is much further away from the coast, despite being an on an island.

The distance off a large continent makes all the difference in the world regarding the climatology of an island. Christchurch, under the Koppen/Geiger scheme of climate classification, is Cfb (marine west coast climate) while Ranohira is Cfa (humid subtropical climate). The major difference here is the overall heat in the area. Being close to the equator, Ranohira has much hotter summers and relatively hotter winters. Both places receive a lot of precipitation.

 

Christchurch is much more developed than Ranohira, therefore urban heat island effects are far more prevalent. Christchurch is also in the rain shadow of the Southern Alps while Ranohira is not influenced by any mountain range. However, Ranohira is much higher so the climates a similar.

Climatology

The Koppen/Geiger scheme of climate classfication defines the majority of locations in New Zealand, including Christchurch, as Cfb. Cfb stands for humid mid-latitude/marine west coast climate with mild winters. The westward coast of a continent has a different climate than the eastern coast due to incoming winds and that air heating over landmass. Since New Zealand is such a small landmass, the air has no time to heat while crossing from the east coast to west coast, where Christchurch is located. The factor that causes the west coast to be slightly drier is the ornographic uplift from the Southern Alps. This mountain range slows the passage of cyclonic storms allowing them to linger over the east coast and drop more rain. As a Cfb, Christchurch never really has a "dry" season; the rain simply decreases. However there is a significant change in temperature of the seasons. 

            Being an island, New Zealand is dramatically affected by the oceans. Christchurch is very close to the coast but the urban heat island effect is very strong here because it is in a valley. The Port hills lie to the East, separating the Bank’s peninsula. Being in this valley also allows for ponding and the clouds to roll just over the surface of Port Hills. I have mentioned before that New Zealand is known as Aotearoa, or Land of the Long White Cloud…this is why.