Friday, July 13, 2018

Orrestranda

Norway has a lot of coastline, most of which is steep and rocky, so I went into this trip knowing beaches would be scarce. One area where sandy beaches are more common is along the Jæren Coast, south of Stavanger, where a broad area of the coast is relatively low and marked by cultivated fields, not fjords and mountains (they're still there, just a few tens of miles farther inland). Like the south end of the Lista Peninsula (previous post) this area may be an old moraine.

AERIAL VIEW

The shoreline consists of sandy beaches, segmented by low headlands. The headlands, at least in this area, appear to consist of cobble and boulder lags, consistent with the moraine idea. The day was damp and windy, so my visit to this beach was brief. Apparently, there are also some nice coarse gravel and cobble beaches along this coast - but none that I saw. Maybe next trip.

Traveling north, we skirted the Stavanger airport and the huge oil field supply center at Tananger. I made due note of the large Schlumberger complex, a nod to a much older epoch of my geologic history (albeit in the Williston Basin, not the North Sea). Our day ended on an island north of Stavanger, reached by a series of deep undersea tunnels -- another chapter in Norway's engineering geology story.

Thursday, July 12, 2018

Havika Beach

Just a short distance east from the previous post, the boulder field is gone, there is more sand, and pocket beaches have formed between bedrock headlands. We swung by Havika Beach (that's what I'm calling it - the Norwegian may translate a bit differently).

AERIAL VIEW

The beach was backed by a field of small dunes, although it turned out that some of the hummocks weren't actually dunes at all, but were underlain by bedrock knobs (or very large boulders).



Lista


The Lista Lighthouse (Fyr) sits at the southwestern corner of the Lista Peninsula near the southern tip of Norway. We were staying in Farsund, just east, and drove out after dinner. There's not much of a beach, and I didn't get down to water's edge anyway, but the shoreline itself was fascinating.

AERIAL VIEW


The broad coastal strip slopes very gradually to the sea and is strewn with large boulders. I suspect that this is a moraine, but I don't know enough about the regional glacial history to speculate more about its origin. 

The aerial photography suggests that in some places cobbles have been rearranged by waves to form indistinct berms, but for the most part the boulders seem to be scattered randomly and the waves don't seem to have had the persistence to create any real shoreline morphology. I suppose this is due to the durability of the underlying surface and the lack of mobile sediment, perhaps combined with an emerging coastline?





Tuesday, July 10, 2018

Grenen

The northern tip of Denmark - of Jutland, more specifically - is a large spit that curves northeastward into the water between the Skagerrat (towards Norway and the North Sea) and the Kattegat (towards Sweden, and eventually, the Baltic).

AERIAL VIEW

The aerial image shows a series of curving beach ridges that record the growth and the migration of this sandy point of land over hundreds or thousands of years. My observations from the ground, besides driving across the coastal plain and old ridges, were mainly out at the tip, where the dunes give way to a low point of sand that eventually disappears beneath the sea.

The beaches are a mix of sand and gravel (as all my favorite beaches are), although the two express themselves quite differently from one place to the next).

The southeastern shore, past the lighthouse and down toward the town of Skagen, is protected by a series of segmented breakwaters. These suggest that this shoreline is retreating - or at least trying to - and is cutting into the beach ridges as it goes. Skagen itself is located behind it's harbor, which is heavily protected behind large jetties.

There's probably a great story about beach evolution here, and one that I suspect has been written about by people much more informed than I - although perhaps in a language I can't read.





Amager Strandpark

 Amager Strand lies just south of Copenhagen, not far from the airport. It's a nourished beach on an artificial island - and relatively new (2005). From what I can tell, the island was built offshore of the original beach - which is now the landward side of the lagoon. But it's possible I don't have this story quite right.

AERIAL VIEW

The beach faces east, toward Sweden across the Øresund. A line of wind turbines lies offshore and the Øresund Bridge can be seen to the south. The shape of the beach is constrained by jetties and piers that act as hard points and keep the sand from getting away.

It was pretty quiet on the day we visited (several weeks ago), but it's an easy train or bike ride from the city and I suspect it gets packed on warm summer days.