In my previous article about searching Paleo-seismic in Sumatra , I several times mention the word Seismic Gap (SG). In this article, I tried to paint a little about how an area said to be in no condition Seismic Gap (SG) . Earthquake kit list
Seismic Gap (SG) was first introduced by Fedotov in 1965 and Mogi in 1969 when they mapped the occurrences of earthquake in Alaska-Aleutian subduction zone (Nishenko and Sykes, 1993). Seismic Gap (SG) is a term used for a tectonically active region but rare earthquake in the long term.
In the southern part of the island of Sumatra and Java, as I described in my previous article, there are subduction zone between the Indo-Australian Plate with Eurasia.Along this zone is active tectonic zone and should frequent earthquakes throughout the year, but if there the area of the earthquake that never happened during the period of time then this area must be cautious.
To find out where the rare kawasan2 earthquake forming Seismic Gap (SG), the first thing one should do is map the points epicenter of 30-100 years ago. From the results of this mapping will be visible region where the rare earthquake so that when we look at the map as if there is a “gap” earthquake there. Now the question is whether the subduction zones around the existing seismic gap (SG)? let’s see figure 1 below.
When comrades attention to areas marked on Figure 1 and Figure 2, it will be obvious that the region there is a seismic gap (SG) and infrequent earthquakes .
As my previous prayers, we mudah2an increasingly frequent minor earthquakes so that no more seimic gap and avoid the rarity of an earthquake causes seismic gap is formed. Better earthquake we cicil than take cash.How Mw (moment magnitude) and when it happened, until now could not be ascertained with certainty.
However there were also some earthquake experts try to calculate the maximum Mw is based on the speed of movement of the plates, the depth and width of the plate by using the formula introduced by Hanks and Kanamori in 1979. Some of the Indonesian earthquake experts, like Mr. Danny Hilman Natawijaya (LIPI) also several times been reminded on several conferences about the dangers of seismic gap in subduction zones and the Sumatra Fault.
Indonesian nation we must always be prepared to face a disaster because we live in a country full of disaster. Hopefully this article useful, and let us ” available science before the disaster “. Hopefully this article on Seismic Gap is beneficial.