The Tasman Sea

The Tasman Sea is in the South Pacific Ocean, and is about 1200x1700 miles located between New Zealand and Australia.  We crossed it over two days to the South Island of New Zealand when our cruise first started, and we crossed it again over two days returning to Sydney from the North Island.  It is often referred as the "the ditch" in both Australia and New Zealand, much in the same way that the Atlantic is referred to as the "the Pond."  At this time of year, it is known for great wind activity, and high seas with passengers and crew often seasick.  The cruise just before ours had experienced this, reported our Captain, but luckily for us we only had a brief glimpse of high seas for a few hours on the start of our cruise, and the sea as like a lake on the return voyage.  Lucky us.

The Tasman's sea mid-ocean ridge was formed over 55 million years ago when the supercontinent Gondwana broke up, forming Africa and other large land masses like Australia.  At the time of this breakup, New Zealand was mostly a submerged continent.  The mostly submerged New Zealand continent, Zealandia, still sits over two moving segments -- the Pacific and Australian Plates, which are colliding.  The land surface of present day New Zealand is being uplifted at the same time it is being wrenched apart, forming a complex geology.  The oldest rocks in New Zealand, uplifted from the sea floor, formed about 510 million years ago during the Cambrian period.  The most recent rocks are days old, formed by the active volcanoes in New Zealand that are part of the Pacific's Ring of Fire along with the Cascade Range of the Pacific Northwest.

The geologic isolation of New Zealand and Australia is what gave rise to their unique flora and fauna.  In New Zealand, no mammals existed prior to the advent of humans only 800 years ago, and the dominant life forms were birds.  In Australia, marsupials and other unusual animal life formed, while humans covered the continent by about 50,000 years ago, and lived throughout the diverse desert, coastal, tropical and mountainous geography and plant and animal life until colonized by European settlers. 

The New Zealand Maori arrived from the east only 800 years ago, it is believed, via South Pacific islands, and had much in common with those forebears.  Even the language has commonalities.  This picture shows the traditional Maori greeting (which Liz and I were lucky enough to participate in at a Maori settlement).

The Australian Aboriginal peoples migrated from the west, it is believed, via routes that have ties with Asia and Africa, but were separated from these forebears by over 50,000 years.  This vast time allowed humans to develop diverse language and cultures across the length and breadth of Australia.  The historical photo at left is of an Aboriginal First People.

These two continents are neighbors across the Tasman Sea but separated by both the distance across the Tasman Sea, as well as complex surrounding past geologic occurrences, and so were colonized very differently by both people, animals, and plants.