7.3 quake hits Philippines (upgrade from 6.9) VERY deep

reply to post by slidingdoor


Interesting theory. I don't know enough about the area to make a guess one way or the other, but I CAN say that I have never seen this type of activity either.

I can't ever remember seeing this many large quakes whithin an hour of each other at that depth. The depth is what has me most interested. I mean, that is REALLY deep. Think about it. 616 km....how deep is the earth, anyways? I have to go some searching on that right now!


Here is the only article on CNN on it righ now. Geez, aren't they behind?!

(CNN) -- A 7.3-magnitude earthquake struck the Philippines' Moro Gulf early Saturday, according to the U.S. Geological Survey. The epicenter of the quake was 102 kilometers (63 miles) off the coastal city of Cotabato and 923 kilometers (573 miles) southeast of Manila. The temblor ran 616 kilometers (575 miles) deep.

LINK

UPDATED!

MAP 7.4 2010/07/23 23:15:09 6.749 123.268 616.7 MORO GULF, MINDANAO, PHILIPPINES
MAP 7.6 2010/07/23 22:51:12 6.494 123.533 576.3 MORO GULF, MINDANAO, PHILIPPINES
MAP 5.4 2010/07/23 22:19:36 6.764 123.545 594.8 MORO GULF, MINDANAO, PHILIPPINES
MAP 7.3 2010/07/23 22:08:11 6.708 123.479 604.5 MORO GULF, MINDANAO, PHILIPPINES

Okay, I found a decent diagram of the earths layers/depth.





So you can see that at 616 km deep it is in the very bottom of the asthenosphere, almost into the mesosphere (lower mantle). This will help some to understand how the P waves can travel so far. When this large of a quake happens that deep, the waves travel outward like a ripple in a lake after dropping a rock.

Picture yourself sitting on a dock and you throw a stone out. The ripples may travel across the water and under the dock, but you don't feel it. Similar to a quake. The P waves travel through the earths mantle and 'ripple'. It is recordable as P waves, but that doesn't mean you feel it.

depths:

# Lower mantle: 49.2% of Earth's mass; depth of 650-2,890 kilometers (406 -1,806 miles)

# Transition region: 7.5% of Earth's mass; depth of 400-650 kilometers (250-406 miles)

# Upper mantle: 10.3% of Earth's mass; depth of 10-400 kilometers (6 - 250 miles)

# Oceanic crust: 0.099% of Earth's mass; depth of 0-10 kilometers (0 - 6 miles)

# Continental crust: 0.374% of Earth's mass; depth of 0-50 kilometers (0 - 31 miles).

so these quakes are REALLY deep. LOL, which we already knew, but nice to put it in perspective

Originally posted by westcoast
reply to post by slidingdoor

 

Interesting theory. I don't know enough about the area to make a guess one way or the other, but I CAN say that I have never seen this type of activity either.

I can't ever remember seeing this many large quakes whithin an hour of each other at that depth. The depth is what has me most interested. I mean, that is REALLY deep. Think about it. 616 km....how deep is the earth, anyways? I have to go some searching on that right now!


Here is the only article on CNN on it righ now. Geez, aren't they behind?!

(CNN) -- A 7.3-magnitude earthquake struck the Philippines' Moro Gulf early Saturday, according to the U.S. Geological Survey. The epicenter of the quake was 102 kilometers (63 miles) off the coastal city of Cotabato and 923 kilometers (573 miles) southeast of Manila. The temblor ran 616 kilometers (575 miles) deep.

LINK

hello happy quake friends!

yes i noticed these large deep quakes , and heres what i found so far ..

acording to this this is not normal .


www.cambridge.org...

great post.

this is very alarming what if the the pressures released from these oil seeps is affecting the pressures under the earth its not impossible our earth relies on its system and we are royally EFFING with it...

thanks for the links everyone great research.!

reply to post by alysha.angel


Hi there!! Thanks for the great info and link. I took this chart from the link you provided:


Table 1.2. Earthquakes with depths greater than 300 km and moments exceeding 2.5 × 1020 N-m occurring between 1906 and 2004. Source: Huang and Okal (1998) augmented by CMT catalog for events occurring since 1996.

Rank Date Area Depth (km) Moment (N-m) MW Environment
1 09 Jun 1994 Bolivia 647 2.6 x 1021 8.3 bend
2 31 Jul 1970 Colombia 623 1.4 x 1021 8.1 isolated
3 17 Jan 1922 North Peru 664 9.4 x 1020 7.9 isolated
4 17 Jun 1996 Flores Sea 589 7.9 x 1020 7.9 bend
5 29 Mar 1954 Spain 630 7.0 x 1020 7.9 isolated
6 29 Sep 1973 North Korea 593 5.0 x 1020 7.8 bend/edge
7 11 Jun 1972 Celebes Sea 332 4.7 x 1020 7.7
8 19 Aug 2002 Fiji 699 4.3 x 1020 7.7
9 26 May 1932 Fiji 560 4.0 x 1020 7.7 bend
10 15 Aug 1963 Peru–Bolivia 573 3.9 x 1020 7.7 bend
10 28 Feb 1950 Sea of Okhotsk 339 3.9 x 1020 7.7
12 25 May 1907 Sea of Okhotsk 548 3.7 x 1020 7.7
13 09 Nov 1963 Peru–Bolivia 573 3.5 x 1020 7.7
13 19 Aug 2002 Fiji 631 3.5 x 1020 7.7
15 19 Aug 1961 Peru–Bolivia 620 3.4 x 1020 7.7
16 09 Mar 1994 Fiji 563 2.7 x 1020 7.6
16 23 May 1956 Fiji 436 2.7 x 1020 7.6
18 26 Jul 1958 Peru–Bolivia 592 2.6 x 1020 7.6 bend



So like you said, this size of quakes at this depth, especially so many clustered together, is NOT normal!

Source:
www.sunstar.com.ph...link


"Earthquake hits Mindanao (7:15 a.m.)

Saturday, July 24, 2010

A MAGNITUDE 6.9 earthquake shook some areas in Mindanao Saturday morning, an official of the Philippine Institute of Volcanology and Seismology (Phivolcs) said.

In a radio interview, Director Renato Solidum said the preliminary data gathered by Phivolcs showed that the earthquake occurred exactly 6:08 a.m. Saturday.

As of 7 a.m. Saturday, Solidum said the earthquake registered an intensity of two in Surigao del Sur and General Santos City.

He also has allayed fears of tsunami occurrence saying that despite the almost magnitude seven quake, the epicenter was very deep.

"Ang importante, masyadong malalim and source ng lindol kaya hindi mapaminsala (The epicenter of the earthquake is very deep that it can never cause any damage)," said Solidum. (Sunnex) "

it was my pleasure ,

you know im a quake buff at heart ,

oh by the by one of the 7 plus quakes has been updated to a 7.6

reply to post by alysha.angel




Yup, you're right! Man, it's hard to keep up with the 'updates'. Here is the most current list from the USGS:

MAP 7.4 2010/07/23 23:15:09 6.749 123.268 616.7 MORO GULF, MINDANAO, PHILIPPINES
MAP 7.6 2010/07/23 22:51:12 6.494 123.533 576.3 MORO GULF, MINDANAO, PHILIPPINES
MAP 5.4 2010/07/23 22:19:36 6.764 123.545 594.8 MORO GULF, MINDANAO, PHILIPPINES
MAP 7.3 2010/07/23 22:08:11 6.708 123.479 604.5 MORO GULF, MINDANAO, PHILIPPINES


[edit on 23-7-2010 by westcoast]

Originally posted by westcoast
reply to post by alysha.angel

 

Yup, you're right! Man, it's hard to keep up with the 'updates'. Here is the most current list from the USGS:

MAP 7.4 2010/07/23 23:15:09 6.749 123.268 616.7 MORO GULF, MINDANAO, PHILIPPINES
MAP 7.6 2010/07/23 22:51:12 6.494 123.533 576.3 MORO GULF, MINDANAO, PHILIPPINES
MAP 5.4 2010/07/23 22:19:36 6.764 123.545 594.8 MORO GULF, MINDANAO, PHILIPPINES
MAP 7.3 2010/07/23 22:08:11 6.708 123.479 604.5 MORO GULF, MINDANAO, PHILIPPINES


[edit on 23-7-2010 by westcoast]

This is EPIC geologists are going to be flipping on this one I dont think this is over either.

The official twitter feed for the USGS twitter earthquake detector just basically said "huh, that's weird."

So yes, it's officially weird.

USGSted

I can't remember a sequence of 3 closely spaced M7+ quakes like this before http://(link tracking not allowed)/1AJnQ6 All deep with weak shaking.

twitter.com...

Originally posted by westcoast
reply to post by alysha.angel

 

Yup, you're right! Man, it's hard to keep up with the 'updates'. Here is the most current list from the USGS:

MAP 7.4 2010/07/23 23:15:09 6.749 123.268 616.7 MORO GULF, MINDANAO, PHILIPPINES
MAP 7.6 2010/07/23 22:51:12 6.494 123.533 576.3 MORO GULF, MINDANAO, PHILIPPINES
MAP 5.4 2010/07/23 22:19:36 6.764 123.545 594.8 MORO GULF, MINDANAO, PHILIPPINES
MAP 7.3 2010/07/23 22:08:11 6.708 123.479 604.5 MORO GULF, MINDANAO, PHILIPPINES


[edit on 23-7-2010 by westcoast]

yes i know im right .

ill look around and see if i cant find any thing more usefull to add a bit later but right now i should be sleeping . awesome thread westcoast.

Latest Earthquakes Magnitude 2.5 or Greater in the United States and Adjacent Areas and Magnitude 4.5 or Greater in the Rest of the World - Last 7 days

earthquake.usgs.gov...

and there has been NOTHING since the 7.4

not even little ones. so far.

Another report, looks like there's a relatively local precedent:

Source: New York BNO NEws

"The USGS estimated that around 21 million people likely perceived weak shaking as a result of the three large earthquakes, but said they were too deep to cause any damage.

The Pacific Tsunami Warning Center said no tsunami had been generated as a result of the earthquakes, mostly due to the depth of the earthquakes. “A destructive tsunami was not generated based on earthquake and historical tsunami data,” the agency said in a bulletin.

On August 16, 1976, a massive 8.0-magnitude earthquake struck 65 kilometers (40 miles) of Saturday’s earthquake, killing more than 7,000 people. "

[Anybody know what depth the '76 quake was?]

[1976 Moro Gulf earthquake and tsunami in wikipedia]

["Initially over 8,000 people were officially counted as killed or missing, 10,000 injured, and 90,000 homeless, making the 1976 Moro Earthquake and Tsunami one of the most devastating disasters in the history of the Philippine Islands." Wikipedia]

[edit on 23-7-2010 by curioustype]

[edit on 23-7-2010 by curioustype]

[edit on 23-7-2010 by curioustype]

[edit on 23-7-2010 by curioustype]

reply to post by westcoast


I wonder....with EQs at this depth...how does that affect the magma? do the waves simply travel through it, or will there be a "magma tsunami" resulting in volcanic eruptions...

Just thinking out loud (or in text in this case)

So, presumably the '76 quake was centred at a far shallower depth, although I haven't found any data on it's depth...? There is a precedent for BIG quakes in that locality though, clearly...

reply to post by curioustype


Here's what I found about the 8.0 quake in 1976

www.drgeorgepc.com...

[atsimg]http://files.abovetopsecret.com/images/member/9a637cf287fd.jpg[/atsimg]

[edit on 23-7-2010 by berkeleygal]

Originally posted by Aggie Man
reply to post by westcoast

 

I wonder....with EQs at this depth...how does that affect the magma? do the waves simply travel through it, or will there be a "magma tsunami" resulting in volcanic eruptions...

Just thinking out loud (or in text in this case)

Huh, I like it when people 'think out loud'. Sometimes great things come from it.

To answer your question though, I have absolutely NO idea. I think, in order to actually displace any kind of volume, it would have to be a much larger quake. (just me thinkin out loud now)



I am on the same mind as berkeleygal. All that action and now NOTHING. It 'feels' to me as if the earth is taking one big breath.....now, will it be let out slowly, with smaller quakes around the 'ring' to off-set all this massive power, or will it be one big huff??? (I'll be keeping an eye on the West Coast of the Contintental US)

CAUSE/AFFECT

[edit on 23-7-2010 by westcoast]

reply to post by berkeleygal


Thanks, I couldn't see any quakes indicated below 150km on their graphic, and it indicates the '76 was at a depth of 0-65km, as you might expect when viewed against the associated Tsunami and damage impact... so 7.6/600 odd km depth, I wonder whether there have been any like that there before?