Tag Archives: ocean

Chasing rainbows

Esperance showing the Recherche Archipelago

Esperance showing the Recherche Archipelago

Esperance is down on the southern West Australian coastline, an absolute jewel for those willing to take the time to visit. Showers accompany us along the road from Albany and rainbows appear – on both sides of the road. By this time the Pajero’s windscreen resembles the surface of Mars, with a sprinkling of craters and two cracks that inch a little further every day. It has also acquired a patina of insect bodies but even so, this rainbow is a jewel.Rainbow 1

The full arc of the rainbow through grubby glass

The full arc of the rainbow through grubby glass

We’re staying with friends I haven’t seen for twenty years, but we reconnected via Face Book and I’m looking forward to the visit. Needless to say, our sat nav isn’t much help to navigate to a farm but we follow the instructions given on the phone and find the farm entrance just on sunset. Yes, this is the right track. Well graded gravel, even the zig-zags between the wide puddles. It has been wet wet wet here. A couple of kilometres from the gate we find the third house and I get out to check we’re at the right place. We are.

The canola crop is ruined.

The canola crop is ruined.

We stay for three nights. Joe and Charlotte and their eldest son farm 23,000 acres where they plant canola and raise cattle and sheep. Their machinery shed is mind-boggling. They have headers and bull dozers and road trains and ploughs and I forget what else. The big machines cost close to a million dollars each, mostly high-tech with computer controlled functionality and air-conditioned cabs (the headers, anyway). Pete is fascinated by the sheer scale of the operation. It costs $3 million to plant a crop, and they might make $5 million. If they get to harvest. This season will be poor. Australia runs in cycles of flood and drought, and this year has been the wettest for decades. The canola stands in shallow lakes, the yellow flowers reflecting prettily in the water.

There’s always work on a farm and Pete goes to help the boys bring in sheep while Charlotte and I go off to do the tourist thing at an area called Duke of Orleans. The scenery here is breath-taking. The granite outcrops are just as spectacular as they are in Albany, but the rock seems more colourful. The sea is turquoise blue, and the beaches are brilliant white, full of silicon. The sand literally squeaks under your feet as you walk. The islands of the Recherche Archipelago dot the ocean, steep granite mounds, such a contrast to the pancake-flat platforms of the Abrolhos Islands. It’s late in the day, and the showers have stopped, although clouds still drift across the sky in groups and the wind is fresh, whisking up the white caps. I manage a few reasonable pictures and then we head for home, talking all the while.

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Next day, Joe takes us out to a granite outcrop at the top of a hill to see if we can find some orchids. It’s quite an adventure. The paddock we cross is waterlogged and despite High rock Esperance1the four wheel drive, Charlotte is not the only one who wonders if we’ll be pushing the car. Oh we of little faith. We’re a little bit early for the orchids but a few have shown their faces. These outcrops are baking hot in summer. Only the toughest plants, like the dryandra, can survive. The delicate orchids wait their turn with the mosses and lichens, responding to the first rains. Charlotte tells me her oldest son was married here, overlooking the land. What a place for a wedding.

Flowers on the rocky outcrop

Flowers on the rocky outcrop

While Joe and his son move another mob of sheep, Pete fixes Charlotte’s ride-on mower and Charlotte and I drive out to Cape Le Grande. You’ve probably noticed the French place names. The French poked around the Australian coast many times, in lots of places but they seem to have left their mark especially around that southern coast. Bruni d’Entrecasteaux visited this area in 1792, and named both Esperance and Recherche after ships in his expedition. The weather is stunning, with blue skies and light breezes, an absolute invitation to climb on the rocks and walk on the beaches. We admire the scenery and the wild flowers, and encounter a kangaroo fossicking around on the beach. She seems untroubled by our presence, apparently grazing on something. We have no idea what.Esperance beachA roo on beach

Looking over the sea at the islands I’m reminded of a story I read somewhere, that a black American pirate operated out of here. My recollection is correct. Here’s the story of Black Jack Anderson Australia’s only known pirate.

From here we’ll be heading for home, east across the Nullarbor. Join us, won’t you?

Moons and tides and stuff like that

Picture of low tide

Low tide at Hervey Bay

I think everybody knows that the moon has an awful lot to do with the height of the ocean’s tide, and so it’s self evident that the highest tides would coincide with the full moon. But hang on a minute. There are two tides each day. Why would that be?

It has to do with gravitational attraction. I wrote about that when I discussed how much you would weigh on an exoplanet. We have established that there is gravitational attraction between the Earth and the Moon. That’s why the Moon orbits Earth. Water, being a fluid, is able to respond to this attraction better than solids, such as mountains. Now while this neatly explains why we have a high tide when the Moon is visible, why would there be a second high tide twelve hours later? The Moon isn’t in the sky, it’s on the other side of the Earth. By rights there should be a low tide, as all the water is attracted to the Moon down there (author points down at her feet).

This does not happen because, as noted in the previous discussion, the power of gravity decreases over distance. The Moon is about 384,000km from the Earth. The opposite side of the Earth is 40,000km further away (the approximate diameter of the Earth) at 424,000km. The water on the opposite side of the Earth to the Moon is attracted less (due to the distance) than the water closest to the Moon, as shown in this simple diagram.Diagram of earth, moon and tidal forces

We have two high tides facing the Moon, and two low tides at the sides. Why Spring tides and Neap tides? For that, we have to consider the sun. The very fact that Earth orbits the Sun illustrates the power of gravitational attraction. When the Sun and the Moon are in the same side of the Earth, as at New Moon, the gravitational attraction of the Sun on the world’s oceans is added to that of the Moon, and we have unusually high tides and low tides. At Full Moon, the Sun is at the opposite side of the Earth from the Moon, so the two bodies might seem to be pulling against each other. Remember, though, the Moon and the Sun both produce two bulges, so the two forces still operate to increase the tide. It stands to reason that if the Sun was to the right of the Earth in the diagram, the forces of the Sun and Moon would tend to cancel each other out. But not completely. That’s because the Sun produces a lesser bulge on the far side of the Earth. It is larger than the Moon, has a far greater gravitational pull, but the relative difference in the distance between the Sun and one side of the Earth, as opposed to the other, is much smaller, so the lesser bulge is less pronounced.

And there you were, thinking this was simple. It is, really, I suppose. But I bet you needed to concentrate.

I love this stuff.

Now go away and work out what the tides would be like on a world with large oceans, and three moons of varying diameter, in three different orbits.

Open your eyes and see

picture of beach low tideIt’s photo Friday again. Just lately I’ve had several remarks about my photos along the lines of ‘you’re so lucky to live in a place where you can see these things’. Well, yes, I guess I am. Not everybody has whales playing in the water close by every spring. And Brahmani Kites don’t fly the skies everywhere, or fruit bats. But I can take photos anywhere. When I lived in Victoria I photographed the local kangaroos and sulphur-crested cockatoos and rosellas. In Perth it was reflections in the river, the view from King’s Park, wildflowers in spring.

Sure, not everybody gets to watch a skein of ibis working a thermal. But then, we don’t have storks here. I’ve never seen the sky black with starlings or a robin hopping across the snow or a blue tit raiding. In visits overseas I’ve photographed white swans and squirrels, reflections in Amsterdam canals. And everybody has sunrises and sunsets, rain on roses, beaches, clouds, bridges, trees…

Beauty is where you find it. Open your eyes and see.

This week’s picture is low tide at Hervey Bay early in the morning. In the top right you’ll see a sea eagle. I got a close-up shot of him later.

 

When I’m not writing I take photos

I’m feeling a tad introspective at the moment. Since I don’t have anything wonderful to say, I’ll show you something wonderful instead.

I live near a beach. I go there quite often, always that same piece of beach. And every single time, I see something new, something different. This was one of those times; low tide, near sundown, warm, calm… This is my idea of peace on earth. © Copyright Greta van der Rol

Please enjoy.