After the Izmir Buca earthquake, which woke people up at 03:29 on November 4, people thought that the magnitude of the earthquake was “around 5.5-6.0”, but according to the Kandilli Observatory, the magnitude of the earthquake was only 4.9. So what was the reason for the earthquake to be felt more?
held on October 30, 2020 7.0 magnitude(According to the American Geological Survey) even two years have passed since the earthquake, their trauma is still felt. During the Buca earthquake, which made him feel strong, many people felt that this earthquake could also cause destruction.
The inhabitants of Buca, at the time of the earthquake, a sound close to thunder they heard. While the noise continued, a very strong shaking started and during the shaking of about 15 seconds, screams were heard from around. People out on the streets were crying after the quake, many saying it was close to the earthquake in 2020. Even Pets They were also afraid and could not come out of their hiding place for a long time.
So what was it that caused this difference in violence?
From ITU Geology Department, Dr. Omer KamaciWe posed this question to He also has 650,000 followers. At the Edge of Science Instagram He also manages the page. His information is as follows:
There are two concepts that are often confused in the presentation of earthquake news: “greatness” and “violence”. The magnitude is the result obtained by instrumentally measuring the seismic waves produced by the earthquake.
The data obtained by the seismometer (graphical output, seismograph) was scaled to the scale proposed by the American seismologist Charles Francis Richter in 1935. (to Richter scale) calculated and presented as a magnitude.
If violence depends on where you meet the seismic waves It is a dynamic concept. The intensity is equal to or greater in size, depending on the distance from the focal point, the floor on which the building sits, and the quality of the building. For example, it is possible to feel an earthquake with a magnitude of M5.0 close to the focal point, with a bad ground and structure, and a magnitude of 6.
However, earthquakes that can cause destruction are earthquakes of M6 and above, where surface ruptures may occur. The intensity of such large earthquakes, It is much larger than the earthquake itself and can increase the destruction.
The expected “Great Istanbul Earthquake” will be felt in some places with a magnitude of 9.0.
In the scenarios produced for the expected Istanbul earthquake, the magnitude is expected to be not less than M7.0. (Forecasts M7 to M7.4). We know that the earthquake will come from the sea, although it is debatable which benefit will be realized in the Marmara Sea.
RELATED NEWS
New Information from the Istanbul Earthquake: It Will Affect 30 Million, There Is A Very High Chance To Happen In 8 Years
So for the violence Districts that have coasts on the Marmara Sea arguably carries a greater risk. It is thought that in districts such as Avcılar, Bakırköy, Fatih, Küçükçekmece, Büyükçekmece and Silivri, it can be felt with an intensity of more than 8.
If we add the quality of the ground and the building apart from the proximity to the focus, especially the old structures built on the infill soils can be damaged in an earthquake on M7. It can be said that the intensity can reach up to 9.0. Therefore, the magnitude is determined immediately after the earthquake, and the intensity is determined by the destruction after the earthquake.
Coming from the sea or land does not change the intensity much.
Because the seas in Turkey are It is the inland sea and its floors are similar to the land. If we had a coast to the ocean and the earthquakes were in the ocean, then the difference between earthquakes on land or on water would be significantly greater. Distance, ground and build quality, It is much more effective than the difference between whether the earthquake is in the inland sea or on land.
Izmir’s earthquake risk is not over yet. A bigger earthquake can strike the city, which has been standing on a fault that has not broken for 352 years.
RELATED NEWS
A Sneaky Enemy Lies Beneath Izmir: 70% Of The Buildings You See In This Photo Can Be Destroyed
We reminded you of this fault on the 1st anniversary of the 2020 earthquake. Along the south coast of the Izmir Bay, the big fault, which crosses the land in Bornova, Göztepe, and has not yet broken, enters the sea a little west of Göztepe. In case of breakage 7.0 magnitude It can create an earthquake and damage the structures in the plain area of the city. 70% will be destroyed.
Both citizens and authorities should take precautions by not forgetting the fact of earthquakes.