This entry is being typed en route to Fiji from L.A. Mom just joined us in L.A. With the help of a couple of good sleeping pills, I got a little sleep during the 3 flights yesterday; the kids did not fare so well. I’m taking advantage of some down time with a little table in front of me to write the final Galapagos blog entry. My 2nd round of sleeping pills will kick in shortly …
3 days later … We’ve been in Fiji for 3 days now – we’re staying with friends Rhonda, Henry & Ben on one of the outer islands (Henry is from here). Absolutely beautiful. Fantastic snorkeling yesterday. Great fishing today. Tenting seaside has been idyllic. Very hot but so far we’ve had cooling breezes. Internet connectivity a challenge here hence the dearth of communication … but we’ll be busy writing in the days to come …
The Galapagos are remarkable for many reasons. Jake talked about the amazing “underworld”. Kaia talked about the wonderful marine iguanas and sea lions. I wrote earlier about the boobies and other lovely birds. And Yvonne talked about the story of species decimation and subsequent recovery efforts. Perhaps what is most obviously remarkable about the Galapagos is the geologic story they tell. They are a living lab of volcanism, that is so easily explored on a cruise such as ours.
To understand these islands, you have to understand the concept of plate tectonics over a “hot spot”. A hot spot is a place in the earth’s mantle that has magma welling up to the crust (through convection). Scientists don’t really understand what creates these hot spots deep in the earth’s core, but the upwelling lava ultimately breaks through the crust and creates volcanoes. Add to this the reality of plate tectonics – whereby the crust is moving over the magma below – and you get a string of volcanoes as the plate moves over the hotspot. The most famous of such a string is the archipelago of the Hawaiian Islands. The island over the hot spot is usually the largest and is “active” (eg. the newest island Hawaii is furthest west) while the oldest island has moved past the hot spot and is now inactive and heavily eroded.
This is exactly what is going on in the Galapagos. The plate that the islands are sitting on is moving east, just as the Hawaiian islands are. So not suprisingly, the eastern islands of San Cristobal and Floreanna are nearly flat and highly eroded, while the western islands of Isabela and Fernandina have high, active volcanoes. In fact they recently discovered (underwater) “sea mounts” off the east side of the islands (see map below). These mounts were Galapagos Islands 4 million years ago before they were eroded away. They also filled in a missing piece of the evolution story for scientists. The oldest present day island is about 5 million years. But evolutionary scientists felt like 5 million years was not enough to explain the adaptive changes of present day wildlife species. But adding in the 4 million years of these previous islands (now sea mounts) apparently completes the evolutionary story.
I’ll start the photo story on the island of Santiago which lies in the middle of the grouping. We went ashore on lava that looked like it had cooled just days or years ago. In fact it was just a little more than 100 years old.
It was remarkable to walk on this lava – the patterns were fantastic. You very easily could imagine that a liquid had cooled.
That afternoon we climbed to the top of Bartholome Island.
Bartholome too was an old volcano. But in this case, you could clearly see the small “parasitic” cones where small fissures allowed magma to form cones around the main cone.
ok … just woke up. 3 more hours to Fiji ..
China Hat was a volcanic “plug” surrounded with slopes of lava. The main attraction here was a sea lion nursery (that Kaia showed photos of). However I was enthralled with the power of the surf crashing onto the lava shores.
Here’s a photo I included in an earlier blog post, showing the tunnels left behind when a volcano subsided and the lava retreated from its lava tube.
In the last few days we moved west to the newest (and most active) islands of Isabela and Fernandina. Isabela has no less than 6 volcanoes on it (its “plate” was moving a little north-south as it also moved east, hence the pattern of volcanoes (see map at start of this entry). These volcanoes are at about 1400m, and have massive craters in them. Even though they haven’t spewed lava in the past 30 years, they are still active; a large crater lake disappeared from volcanic activity about 20 years ago. We went ashore on Isabella and climbed up past a crater lake just inside the island that was part salt and part fresh.
Fernandina is the youngest island, and fully erupted in 2010. Victor was leading a tour at Genovesa Island at the time and received permission to change his itinerary to take his clients to see the eruption. Now THAT would have been pretty cool!
One of our favorite shore visits was on the smaller island if Rabida, known as the “red island”. I believe it is mostly a high iron content that led to this colouration.
I’ll finish out the blog with some photos that capture a bit of what it’s like to live aboard a Galapagos cruise boat.
We parted company with our crew and cruise companions upon arriving back at Baltra Island. The cruise had surpassed any of our expectations. Unfortunately expensive – few folks (well … OK … 60,000/yr) are as fortunate as us to be able to experience this. But probably just as well for those lovely creatures.
Wow … the Galapagos. Next entry we’ll be back on mainland. Until then ….