Very slow changes

Ice reflects 80% of the sun’s light back to space. Ocean waters absorb 90% of the light. As a result, when arctic ice melts, the amount of heat absorbed in the ocean increases by 450% (that is 100 X 90/20). I looked at photos I’d taken of Greenland as I flew over it on June 8, 2006, and I could actually see that. Ice is the brightest thing you can see from an aircraft flying 11 kilometers up in the air, at the edge of space. And sea water is the darkest.

A long non-stop flight to LAX can be boring. I’d wandered over to the galley, and poured myself a glass of water. The window shade was open, and I looked out, and saw icebergs being birthed. Rushing back with my camera, I captured a sequence of photos which I still look at now and then. I’d wanted to go back to those frozen northern lands, but never took the time to work that into my schedule. Now I wonder whether I will ever do it, while they remain frozen.

An article in Moscow Times first alerted me that this year was a disaster in more senses than I had realized. A portion of the Arctic Ocean called the Laptev sea usually freezes early, and causes icing to start over the rest of the ocean. This year it is terribly delayed, due to the exceptionally hot summer. The weather changes from year to year, so how exceptional is this? If you look at the record of ice formation in the thirty years from 1980 and 2010, then this year is an extreme outlier; it hasn’t happened so late in any other year.

Why am I worried about my future travel plans? It is because the loss of sea ice is a runaway process. If the ice becomes patchy, and uncovers more water, then the oceans absorb 450% more heat from the sun in summer, and stay warmer into winter. This causes less ice to form in the following year, so exposing a larger surface of the sea in the next summer. And so it goes. Maybe in four or five years I will find myself able to travel to Iceland or Greenland. And by then the winters could just be more balmy. Of course, it is not only my collection of photos which will suffer.

Filling a gap in history

The island continent of India drifted for 70 million years through the Tethys Ocean. It separated from Gondwanaland about 120 million years ago and collided with the Eurasian continent around 50 million years ago. 70 million years is enough time for large families of animals to evolve and die. So there must have been families which arose in the Indian landmass and migrated to the rest of the world later. The first such family has now been identified.

These are the Cambaytheres, a genus of fossil animals found at the bottom of an open-cast lignite mine outside of Surat in Gujarat. These 57 million years old fossils seem to be the origin from which all modern even-toed ungulates radiated out. These include horses and zebras, tapirs, as well as rhinoceros. The Cambaytheres were first described in an article published 6 years ago but I read about it only recently from a monograph published this year. The Cambay shale deposits have also yielded a very rich variety of other fossils from those times, and I’m sure we’ll be reading more about new finds from them.

The monograph has a very clear statement that although the genus is not the direct ancestor to any extant even-toed ungulate, it is the best possibility for the last common ancestor of all of them. Previous claims to the origins of this family are based on fragmentary fossil remains, or, sometimes, on conjectural remains. By the early years of the 21st century the possibility that the ancestors of horses originate in the Americas, Europe, and Africa had already begun to seem remote. A lot of attention then focused on new findings in China. Now, with a large collection of remains, from three species of this genus, much more can be said. Mysteries which remain are the routes through which the animals dispersed across the world, and then radiated into a large number of species in a few tens of thousands of years.

Walking through a small village

We walked a short distance through the seemingly inhospitable terrain near the border between Madhya Pradesh and Maharashtra. This was in the spring of 2006, on our first visit to Pench National Park. In medieval times this was the kingdom of the Gonds. The five century long history of the Gond rajas came to an end in the 18th century CE, when the Maratha armies captured their kingdom. The Gond state was completely demolished, and in present times we know these people only as a rural population of subsistence farmers. The only memory of that large kingdom is the name Gondwana by which the region is still known, and which was back-propagated by geologists to give a name to the southern part of the continent of Pangaea which formed 300 million years ago, of which the local rocks are a remnant.

The vegetation changed as we came nearer the village. I did not recognize it then, but the mahua trees (Madhuca longifolia) surrounding the village were planted by them. In some places these mahua groves have a sacred status. It is interesting that mahua is a keystone species in such areas, encouraging the growth of several other kinds of plants, and perhaps attracting insects and birds. I guess the ecological engineering of Gonds is something that we are yet to completely understand. Contemporary records tell us that the late medieval period in this part of India was much drier than it is today, and there were many efforts to conserve water. It would be interesting to take a wider view of this kind of ecological engineering to see its effect on conservation of this kind. This history surely has something to teach us for the future.

The village was extremely small, just a few houses clustered together. I was fascinated by the painted walls of the houses. The dado was common. In offices and hospitals, the dado usually has a darker stripe on the bottom and a lighter colour on top, to hide accidental stains. Here it was reversed as you can see. I wonder why. I liked the patterns painted around the door. The long shaft of the yoke was fascinating. I suppose the length of the shaft means that the force applied at the yoke will be more nearly horizontal, resulting in easier rolling. The trade-off is that starting and stopping will be harder. Clearly this is a cart made for long-distance hauling on a flat terrain!

The village was not very empty. Most men were out, perhaps at work. Around a courtyard we found three generations of a family. The matriarch was almost bent double. Each family owned cattle. So I suppose milk and sunlight must be plentiful. Why would osteoporosis be a problem here? I found later that Gonds usually don’t drink milk as adults, perhaps due to widespread lactose intolerance. I suppose all the households in the village had three or four generations living together, and the families would probably be related to each other. I realize that I knew very little about the culture and history of the Gonds. That’s something I should repair; I share a country with them.

Rage against the dying of the light

Like many others, I must have discovered Dylan Thomas’ poem in my teenage years. In those days it was a sort of a secret anthem on how to live for a cryptic club. The anthem adapts to circumstances. On a late afternoon walk through the Marine National Park in the Gulf of Kutch, I thought about the poem again. People I knew in Wuhan were already in lock-down, and in February it was already clear that the pandemic would strike some time, but that was not what was uppermost in my mind.

We strolled for more than a kilometer out to the waterline. The tide in this gulf is spectacular, and the receding sea had left pools in which we could see sponges, puffer fish and crabs. Over the years I’d discovered that I was similar to a migratory shorebird, like the common greenshanks (Tringa nebularia), which visits these pleasant coasts in winter, striding through tide pools, stopping to inspect things, turning over little stones. The sun was about to set. “Time to go back”, said someone. “Just a few minutes more”, I said, trying to prolong the pleasant day, raging against the dying of the light.

The poem is about living right, as all teenagers know. It is not about dying.

The six seasons: coda

We were taught in school that astronomy determines climate, and the four seasons. Let’s take the astronomy first. From our earthbound view the sun seems to move north and south across the sky over the year. The extreme points are reached on the days of the solstices: the longest day and the longest night. The climate for a featureless earth follows from this, alternate heating and cooling of the atmosphere above the earth would produce two extremes. Culture determines the seaons: how would you want to divide the parts between the extremes of hot and cold? Into two, or four, or twelve? That would determine how many seasons you have. The simple geography of mid-latitude Eurasia and a large part of Northern America gave rise to the cultural artifact of the four seasons.

But there’s more to the climate than this simple and ancient model. The heating by the sun causes convection in the atmosphere. The rotation of the earth then breaks these convection cells into several northern and southern pieces. Approximately around the equator, these convection zones come together and create the monsoon. So, any continent that lies just north or south of an open equatorial ocean has monsoons. In our present geological epoch that is mainly Asia and Australia.

Unlike the rest of these two continents, India is also cut off from the polar circulation by the high east-west barrier of the Himalayas. This means that its climate is again particularly simple: the seasonal heating and cooling by the sun, and its interaction with the monsoon can be summarized into the six seasons. Essentially, the seasons of the mid-latitudes get interrupted by a season of rainfall. Summer is duplicated into grishma and sharad, and interrupted by varsha.

The rest of the world can be more, or less, complicated. The Aztec and Mayan civilizations counted two seasons. At the other end of the scale, Korean tradition counts as many as 24 seasons, Japan counts 12 in its classic poetry. The counting of seasons is a wonderful convergence of physical conditions and culture.


Photos from top to bottom: (1) Winter in the Thar desert of India (2) High summer in Greenland (3) Late spring in Germany (4) Early winter in Korea, the season of Ipdong.

Ross finds a dinosaur

If you saw Friends! in its first season, you might remember that in a rather momentous episode Ross goes away to China for a week. He explained to Monica that a bone had been discovered, and that he had to get it. It was a very current episode for 1994, when new dinosaur fossils were beginning to be unearthed across China. When I passed through Shanghai a few months ago I decided to visit the Shanghai Museum of Natural History. It is easy to find, since there is a metro station named for the Museum, right next to it. The discoveries in China have completely changed our view of dinosaurs. The sheer number of fossils has allowed studies of entire life histories, including growth rates and reproductive behaviour, and even their colour. The fossil whose photo is featured is one of a 100 million years old genus called the Psittacosaurus, because of its parrot-like bill.

Next to the case with the fossil skeleton is a big draw: an animatronic model of one of the species of Psittacosaurus. The explanatory note says that the model is programmed to show it defending its nest full of eggs. There is physical evidence of the colour and proto-feathers. So much so that, if I were an expert, I would be able to tell the species by the colour, like in some bird genera today. I’m sure that much research has gone into the behaviour being exhibited. Predictably, the display was very popular with children, as you can figure out from the soundtrack, if you play the video. For a while now, movies such as Jurassic Park needed a reboot to display dinosaur feathers and their colours more accurately. This model is a nice way to get rid of the outdated iconography of dinosaurs.

The joy of mucking about

I thought I was not much of a beach person until a few years ago, when I realized that I actually like beaches which are long and shallow, on seas which are not dead. There are beaches which fit all these descriptions along the Gulf of Kutch near Dwarka. Due to its peculiar shape, the Gulf of Kutch has huge tides twice a day. On one of the days I was nearby, the sea level changed by 8 meters between high and low tides at the end of the Gulf. The coastal shelf is very gentle, so this allows you to walk kilometers into the sea at low tide.

At the Marine National Park near Dwarka, I went for such a walk. This is what I enjoy about beaches, being able to walk for long times at the place where the water and land meet each other. Such places around India are full of hermit crabs which have donned the shells of dead sea animals. Every shells that I saw was on the move. I’d first noticed these zombie shells in the Andamans, where I fell in love with beaches.

I made my way back to the tide line when the horizon started tilting up to the sun. The tide was beginning to turn and I was keen to get away from the slippery rocks and corals while there was still light. The long shadows of the evening threw the tracks of the hermit crabs into clear relief. They seem to be constantly on the move, foraging for food, and occasionally searching for a better shell to move in to. I thought it was a day well spent, doing little other than turning rocks over to inspect whatever is hiding below it.

Hallucigenia

In the last thirty years there has been an explosion of fossil discoveries in China. These have added significantly, perhaps even revolutionized, much of our earlier knowledge of some geological eras. I knew that museums in China have wonderful collections of fossil dinosaurs. I was surprised to find that the new discoveries span a much longer history. The Cambrian, which started about 540 million years ago, and lasted for over 50 million years, is part of this. Our earliest knowledge of the biota of the Cambrian came from the Burgess Shale, found in Canada in 1909. The slow fragmentation of the large super-continent of Pannotia, its warm coastal seas, and the complete lack of land plants still supported an immense variety of aquatic life. One of these animals was the Hallucigenia whose fossil from the Chengjiang shales I saw in the natural history museum in Shanghai.

Model of pre-Cambrian animal Hallucigenia

The fossil looks like a crude sketch. It was first described in 1977, when it was reconstructed upside down and front to back. Walking on seven pairs of spiny legs while waving seven tentacles on its back made it something that could be dreamt up on a trip, hence the name Hallucigenia. It turned out that the blob at one end of its body is not its head, but the contents of its guts squeezed out by the clay which buried it. Finally, with electron microscopy, in 2015, a final picture could be created not only of the way it looked, but also how it walked (what a difference good optics makes!). What the animation above does not show is the circle of teeth around the throat, and that is new information which connects it to the family tree of insects. It was once thought that most of the Cambrian animals left no descendants; this may not be true.

Above the rift valley

45 million years ago the continental plate of Africa began tearing into three. About an hour’s drive westwards from Nairobi you get to see the long crack where the Somali plate is separating from the Nubian plate. We took the B3 Escarpment road and stopped at a gap between souvenir shops. It was early in the morning, and sun had not yet burnt the chill out of the air. We stood in the way of the upward rushing air and looked out at that enormous valley, thinking of the grasslands teeming with wildlife, and how in another 45 million years it will be part of the sea separating the continents of Nubia and Somalia.

I looked around at the shops around us. Several sold the usual carvings and paintings. But there were a few which sold sheepskin. I’m sure that this wouldn’t last long in the humidity and warmth of Mumbai. But some of the shops had nice paintings of animals. For that matter, the railing separating us from the long drop to the valley was also painted. We admired them and moved on.

The road drops steeply to the floor of the valley after this, and both of us kept looking out at that enchanting view. On the way back, a few days later, I noticed the distinctive flora of this region: the very tall African candelabra (Euphorbia ammak) also known as the Candelabra spurge. Just before the road climbed steeply I saw a church which looked totally out of place. As I took the photo, The Family noticed a signboard which said that it had been built by Italian prisoners of war during the second world war. That gave me a little handle with which to tease information out of the net. It seems that B3 was built by these same prisoners. The search also led me to a book called No Picnic on Mount Kenya, which is an account by one of the prisoners, Felice Benuzzi, who broke out of his camp to go and climb Mount Kenya. It is quite a read.

I leave you with a superb photo captured by The Family from our car as we made fitful progress through the horrendous traffic on B3 in the evening.

Instant winter

When I booked tickets to Nairobi on a flight which left Mumbai before 6 in the morning, I was looking forward to arriving at 10 AM, with a whole exciting day in front of us. I’d forgotten that, this being an international flight, we would have to be awake half the night. As it was, we finished the formalities quickly and had a very early breakfast in the lounge before boarding. My first priority was to catch up on sleep. When I woke up we were halfway through the flight. The map told me that we were flying over the Carlsberg ridge. This is one of the more active zones on the earth’s crust, the border where the Indian and Somali continental plates are pulling apart. This geological feature is named after the brewery which financed the expedition which discovered the ridge. What a lovely and positive piece of advertisement; I promised to raise a glass of their brew to cheer their commitment to science. I peered across the still sleeping figure of The Family. The sea looked pretty calm.

A little later we were over Africa. A whole new continent! We’d sighted land a little south of Mogadishu. I gazed down at the parallel rows of clouds which you see in the photo above. I’d never seen this kind of weather before. I was to find later that these so-called cloud streets are parallel to the direction of the wind. So the cloud street showed me that a cool wind was blowing in from the sea as Somaliland heated up. The land below us remained brown as we passed over the equator. Another lifetime achievement for us; this was our first time in the southern hemisphere. In an instant we’d passed from summer to winter!

Everything would be new and different (even the style of artwork on the sachets of salt and pepper given by the airline). We peered out of windows eagerly as we landed in Nairobi. The landscape was brown and dry, as it had been as we flew over Somalia and inland to Kenya. “Karibu”, one of security men said in welcome as he showed us which way to go. The Family and I looked at the windows near the immigration queue; zebras and acacia trees, lions and elephants were painted on them. We would see them soon enough. I pulled a jacket over my t-shirt. It was colder than a winter’s day in Mumbai.