Wednesday, March 23, 2011

Mushroom Cluster

A cluster of large mushrooms appeared after a recent rain. I haven't seen this species before. Here are some pictures.

After a few days, mushrooms were open:

I spied a couple of flies: suspect they are the spore vectors.

I wanted to take a peak under the umbrella:

Friday, March 11, 2011

Great Cascadia Earthquake of 1700 M9.0

Yesterday's humongous earthquake in Japan is already listed in Wikipedia as the 7th biggest earthquake, based on its Magnitude of 8.9. Wow! I was drawn to #6, Great Cascadia Earthquake, as it was on the North American Continent---the home continent, with a Magnitude of 9.0.

The date and time of the Great Cascadia Earthquake in Oregon, Washington, and BC, was reconstructed by several methods. In particular, detailed Japanese descriptions/records of a Tsunami in the year 1700 made it possible, four hundred years later, to reconstruct the time of the Great Cascadia Earthquake. They arrived at an estimate of the evening (about 21:00 local time) of 26 January 1700. The paper is unavailable to download, as it is published in the journal Nature:
K Satake, K Shimazaki, Y Tsuji, K Ueda. Time and size of a giant earthquake in Cascadia inferred from Japanese tsunami records of January 1700. Nature 379, 246-249 (1996).

The Abstract:

GEOLOGICAL evidence shows that great earthquakes have occurred in the recent prehistoric past in the Cascadia subduction zone, off the Pacific coast of North America. The most recent event (or series of events) is dated at about 300 years ago, but the precise date and magnitude have not been determined. Geological investigations have not been able to distinguish a single giant earthquake from a series of great earthquakes occurring over a timespan of a decade or two4, although this information is important for the assessment of future hazard. We have found several tsunami records in Japan from AD 1700 with no indication of a local cause. Historical earthquake records and palaeoseismic evidence indicate the absence of a large earthquake in 1700 in South America, Alaska or Kamchatka, leaving Cascadia as the most likely source of this tsunami. The estimated time of the earthquake is the evening (about 21:00 local time) of 26 January 1700. The magnitude is estimated as 9 from the tsunami heights, in which case the earthquake ruptured the entire length of the Cascadia subduction zone2. These estimates are consistent with Native American legends that an earthquake occurred on a winter night.

A review is found in html:here.

Tree ring studies (including one by Yamaguchi et al. have also corroborated the 1700 date. And on Google Scholar one notes several studies of sediment layering in estuaries along the Oregon Coast.

I am particularly drawn to the paper by Ludwin et al.: an estimate--perhaps not as accurate as the above, but more fun to read---from pacific Northwest native stories: Downloadable here. From an analysis of Native Stories (accounts including oral remembrances of great grandchildren) they arrived at a close estimate, as referenced by Satake et al.:

The stories were told between 1860 and 1964. Figure 2 tabulates the accounts
and gives estimated date ranges. Date range minima and maxima are 1400 and 1825. All estimates span the interval between 1690 and 1715, and the average value of the mid-points of the date ranges is 1690. Discarding the earliest and latest midpoints yields an average midpoint date of 1701. This is remarkably consistent with the 1700 date of the most recent CSZ earthquake.

Here is a list of the historical 24 earthquakes of highest magnitude,
from Wikipedia. Notice that on the very day of the 7th Earthquake,
this was added to the Wikipedia record.

1May 22, 1960Valdivia, Chile1960 Valdivia earthquake9.5
2March 27, 1964Prince William Sound, USA1964 Alaska earthquake9.2
3December 26, 2004Sumatra, Indonesia2004 Indian Ocean earthquake9.1
4November 4, 1952Kamchatka, Russia (then USSR)Kamchatka earthquakes9.0 1
5August 13, 1868Arica, Chile (then Peru)1868 Arica earthquake9.0 2
6January 26, 1700Pacific Ocean, Japan and USA and Canada1700 Cascadia earthquake9.03
7March 11, 2011Sendai, Japan2011 Sendai earthquake8.94
8February 27, 2010Maule, Chile2010 Chile earthquake8.8
9January 31, 1906Ecuador–Colombia1906 Ecuador-Colombia earthquake8.8
10November 25, 1833Sumatra, Indonesia1833 Sumatra earthquake8.8
11February 4, 1965Rat Islands, Alaska, USA1965 Rat Islands earthquake8.7
12November 1, 1755Lisbon, Portugal1755 Lisbon earthquake8.7 5
13July 8, 1730Valparaiso, Chile1730 Valparaiso earthquake8.7 6
14March 28, 2005Sumatra, Indonesia2005 Sumatra earthquake8.6
15March 9, 1957Andreanof Islands, Alaska, USA1957 Andreanof Islands earthquake8.6
16August 15, 1950Assam, India – Tibet, China1950 Medog earthquake8.6
17September 12, 2007Sumatra, IndonesiaSeptember 2007 Sumatra earthquakes8.5
18October 13, 1963Kuril Islands, Russia (USSR)1963 Kuril Islands earthquake8.5 7
19February 1, 1938Banda Sea, Indonesia (Dutch East Indies)1938 Banda Sea earthquake8.5
20February 3, 1923Kamchatka, Russia (USSR)Kamchatka earthquakes8.5 7
21November 11, 1922Atacama Region, Chile1922 Vallenar earthquake8.5 8
22May 24, 1751Concepción, Chile (Kingdom of Chile)1751 Concepción earthquake8.5
23October 20, 1687Lima, Peru (Viceroyalty of Peru)1687 Peru earthquake8.5
24December 16, 1575Valdivia, Chile (Kingdom of Chile)1575 Valdivia earthquake8.5

Tuesday, March 8, 2011

Erythrina variegata: calendar tree of the Pacific

Erythrina variegata and its congeners are widely used as calendrical markers in Pacific Island cultures.  I have selected it, for now, as a header because it serves as an exemplar of certain research interests.  This particular tree is located on the campus of Kagman High School.  It is a tree worthy of a tale.

Despite its status as a cultural icon on numerous Pacific islands (7 I know about), on Saipan it is not a tree that is welcomed by farmers, because it serves as a reservoir for pest species.  Aubrey Moore identified it as the larval host of   Eudocima fullonia, a fruit-piercing moth.  The Erythrina gall wasp is also a problem, as noted by Aubrey Moore of the University of Guam (pers. comm.): "the erythrina gall wasp invaded Hawaii where it has become a huge problem, killing their endimic erythrina and the tall wiliwili commonly used for windbreaks.  This gall forming wasp has rapidly spread to other Pacific islands."   He also states that this tree is not considered endemic to Pacific Islands.

That latter point is of interest, because the flame tree is honored by a festival in spring / early summer, on Saipan, yet it is not a native species.

Erythrina spp. are reported as caledrical markers in New Caledonia, Palau, Lamotrek (Caroline Islands), Pohnpei, Hawaii, Tahiti, and Samoa. Even more interesting, on most of these islands its flowering is associated with pelagic events, including shark hunting, drifting logs, and whaling. Klee, in his M.S. Thesis about Palauan time reckoning, mentioned that this tree is of special interest as a dry season blooming tree, and that it always blooms the same time every year, regardless of the weather.

[caption id="attachment_10" align="alignnone" width="420" caption="Erythrina variegata at Kagman High School, 18 February 2011."][/caption]

The photo in the header was taken on February 18, 2011. This is a tale with many more twists and turns, as I intend to follow up upon.