Dust flux, Vostok ice core

Dust flux, Vostok ice core
Two dimensional phase space reconstruction of dust flux from the Vostok core over the period 186-4 ka using the time derivative method. Dust flux on the x-axis, rate of change is on the y-axis. From Gipp (2001).

Thursday, January 26, 2017

"It's like being on the Moon!"

. . . said just about everyone about the terrain around Hamningberg.

Hamningberg is an abandoned fishing village in the northeast tip of eastern Finnmark--the northern part of Norway. The town was largely depopulated in the 1960s, although people still used some of the homes there as summer cottages. There was even a small coffee shop (or was, in 1993). What made the town special is that it is one of the few villages where buildings predate the war.

When the Germans retreated from Finnmark during the last winter of the war, they were ordered to burn everything. However (so I was told), the commander of the German forces stationed in Hamningberg took pity on the people, and so he disobeyed the order. This was probably made easier knowing that no other German units would be passing through to realize this. So while every other village in Finnmark was razed, Hamningberg remained.

 Things to do in town include visiting the abandoned German gun-emplacements, and, if you have a flashlight, the pillbox and the network of tunnels between ammunition storage areas, the observation area, and the rails for the gun.

WW2 vintage barbed wire

The picture quality isn't all that great--the slides look okay, but the scanner isn't doing a very good job of scanning them.

What I was most interested in seeing in the area was the landscape. Everyone I knew in Finnmark told me that going there was like going to the moon. Even this site describes it as a "moonscape".

Just for reference, here is a real moonscape.

The local geology around Hamningberg consists of alternating sequences of sandstone and shale, which have been folded so that the bedding is nearly vertical. The shale tends to get eroded out, but the more resistant sandstone beds remain as broken walls across the landscape. Craters are absent. So, the place doesn't look like the moon at all.

But there is something otherworldly about the place. I think the reason for this common description--like the surface of the moon--reflects the fact that the landscape looks radically different from any other landscape that most people have ever seen.

For one thing, there isn't a lot of vegetation. But (at least here in Canada), there are a lot of shield areas with practically no vegetation. The other reason has to do with the geometry of the landforms of the area.

In the early days of computer-generated landscapes, there were experiments in which people would be shown some of the simulations and asked to rate them as being realistic or not. Most of these landscapes were generated using simple rules, with a seed shape (usually a triangular pyramid) and a characteristic fractal dimension. It turns out people were remarkably good at picking out the landscapes which had fractal dimensions within the typical range of landscapes on earth. Anything outside of this range was "otherworldly".

For a computer-generated landscape to resemble Hamningberg, it may have to be seeded with rectangles rather than pyramids. I don't think the fractal dimension is anything unusual, however. But the description of the area is being otherworldly may reflect the preferences that people have for landscapes that conform to their ideas of what constitutes a "natural" landscape.



  1. RE: Moonquakes of tidal origin discovered. Interesting and elegant data analysis.

    Using Poincare mapping (PM).

    "Periodicity Analysis: Similar waveforms at near monthly intervals suggest that the events occur in very close proximity to one another and they are either triggered or induced by the Earth-Moon tide."
    "We analyze to find the periodicity of deep moon- quakes by the method of Poincare mapping (PM). Nonlinear structure and hidden periodicities can be examined graphically by PM [6]. The PM method dis- tinguishes a deterministic system, whose complete behavior can be expressed with an infinite precision, from a chaotic system, which is also deterministic but is unpredictable. Let Ii(k) be the time interval from (k-1)th event to the kth event of the ith deep moonquake source (nest) and Ii(k+1) be that to the (k+1)th event. The PM is constructed by scatter plotting Ii(k+1) versus Ii(k)."

    CHAOTIC OCCURRENCE OF SOME DEEP MOONQUAKES. Junji KOYAMA, Earth Planet. Sci., Hokkaido University, Sapporo 065-0810 Japan

    Fourier analysis of periods:

    "First, we examine the spectra of moonquake occurrence times at each deep source region, and observe known tidal periodicities, notably those at ~27 days and 206 days. Application of spectral methods for the analyses of point processes (discrete events) allows us to resolve closely spaced tidal periods not previously seen in moonquake data."

    Temporal and spatial properties of some deep moonquake clusters
    R. C. Bulow,1,2 C. L. Johnson,1,3 B. G. Bills,1,4 and P. M. Shearer1
    Received 18 October 2006; revised 24 March 2007; accepted 15 June 2007; published 15 September 2007.

    Sorry no paper links it is late at night.

  2. Some links on background, a researcher, and available moonquake data:

    Background links:

    A researcher, and available data:


  3. If I remember from a paper moonquakes are often from meteor impacts, crater walls collapsing, and internal "crackling". I think most of the moon is thought of as solid non-molten.

  4. https://www.researchgate.net/figure/229401485_fig2_Fig-2-Delay-coordinate-maps-of-moonquake-times-from-several-clusters-see-map-in-Fig

  5. I came here to post some thing you might also find interesting on geomagnetic reversal statistical properties. (It looks like room for discovery) I'm sure there are data sets around.

    Quoted from:
    "Statistical properties of reversals" section of wiki article on Geomagnetic reversal

    "Several studies have analyzed the statistical properties of reversals in the hope of learning something about their underlying mechanism. The discriminating power of statistical tests is limited by the small number of polarity intervals. Nevertheless, some general features are well established. In particular, the pattern of reversals is random. There is no correlation between the lengths of polarity intervals.[14] There is no preference for either normal or reversed polarity, and no statistical difference between the distributions of these polarities. This lack of bias is also a robust prediction of dynamo theory.[10] Finally, as mentioned above, the rate of reversals changes over time."

    The randomness of the reversals is inconsistent with periodicity, but several authors have claimed to find periodicity.[15] However, these results are probably artifacts of an analysis using sliding windows to determine reversal rates.[16"

    "... A random reversal pattern with inhibition can be represented by a gamma process. In 2006, a team of physicists at the University of Calabria found that the reversals also conform to a Lévy distribution, which describes stochastic processes with long-ranging correlations between events in time.[17][18] The data are also consistent with a deterministic, but chaotic, process.[19]"

    Related articles: