Earthquake detection system facts:
If we want to know why we need Google’s earthquake detection system, we must watch out the below facts.
- Scientists used the Richer Scale for many years to measure earthquakes but now largely follow the “movement magnitude scale” which USGS says is a more accurate measure of size. Google’s earthquake detection system may help further.
- Magnitude measures the size of an earthquake by the energy released at the source of the quake and is determined from readings on seismographs.
- The Richter scale was named after seismologist Charles Richter, who first developed this method of measuring quakes in 1935.
- The largest recorded earthquake occurred in Chile on May 22, 1960. It measured 9.5 and triggered a tsunami that swept across the Pacific Ocean, killing scores of people in Hawaii, Japan, and elsewhere.
- Among other measurements is moment magnitude, which is a measure of the amount of energy released — an amount that can be estimated from seismograph readings.
- Japan also uses a seismic intensity scale from 1 to 7 that measures the strength of seismic motion and usually gets stronger the closer you get to the epicenter of an earthquake.
Deadliest earthquakes from 1990 to present:
Jan 12, 2010 – Haiti – 316000 killed (magnitude 7.0)
July 27, 1976 – Tangshan, China – 255000 Killed (magnitude 7.5)
Dec 26, 2004 – Sumatra, Indonesia – 227,898 killed in the quake and resulting Tsunami (magnitude 9.1)
Dec 16, 1920 – Haiyuan, China – 200000 killed (magnitude, 7.8)
Sep 1, 1923 – Kanto, japan – 143,000 killed (magnitude 7.9)
Oct 5, 1948 – Ashgabat, Turkmenistan – 110000 killed (magnitude 7.3)
May 12, 2008 – Easter Sichuan, China – 87,587 killed (magnitude 7.9)
Oct 8, 2005 – Pakistan – 86000 (magnitude 7.6)
Dec 28, 1998 – Messina, Italy – 70000 killed (magnitude 7.2)
May 31, 1970 – Chimbote, Peru – 66000 killed (magnitude 7.9)
The biggest problem with Earthquake detection system:
- There is no proper warning system for Earthquakes.
- We only get vague warnings like “an Earthquake can occur in this area in the next 100 years or so”.
- Sysmologists warn about any big earthquake for a large time scale (100-300years) which is hard to predict for us.
- Earthquakes pose inevitable risks to everyone who lives in a seismically active region. Even though the hazard is well recognized, no one knows when an earthquake will strike or how severe it will be.
- Despite considerable effort over the years to develop the capability to predict earthquakes, it is unclear whether this ever will be achieved.
- By disseminating and implementing the cost-effective planning, design, construction, and response measures developed through NEES research, it will be possible to reduce injuries, loss of life, property damage, and the interruption of economic and social activity that have long been associated with strong earthquakes in densely developed regions.
Googles approach to earthquake detection:
Google recently conducted an experiment using its subsea fiber optic cable, which showed that it could be useful for earthquake and tsunami warning systems.
Valey Kamalov and Mattia Contono from Google Global Networking posted a blog detailing how Google plans to detect earthquakes.
“Last October, an idea came to us: we could detect earthquakes based on spectral signatures performing a spectral analysis of Stokes parameters to look at frequencies that are typical of earthquakes”, they said in the blog post.
Google’s earthquake detection system using Submarine communication cables:
A submarine Communication cable is a cable laid on the sea bed between land-based stations to carry telecommunication signals across stretches of ocean and sea.
There is a separate dedicated website to monitor these cables.
Typical Submarine Cable System:
- Modern submarine telecommunications cables rely on a property of pure glass fibers, whereby light is transmitted by internal reflection
- Because the light signal loses strength en route, repeaters are installed along the cable to boost the signal.
- New systems rely on optical amplifiers – glass strands containing the element, erbium. Strands are spliced at intervals along a cable & then energized by lasers that cause erbium-doped fibers to “lase” & boost optical signals.
The challenges facing submarine optical communication:
The following are the challenges faced by Google’s earthquake detection system while using submarine optical communication fibers.
Capacity & design:
- A typical submarine communications cable has a diameter of 17 mm—about the size of a garden hose—for deep-water cable, to 70 mm for heavily armored cable in shallower water.
- The shallower the cable, the thicker its armor must be.
- The fiber optic core is typically encased in high-tensile-strength galvanized steel wires surrounding a copper sheath, surrounded by more layers of steel armor and polyethylene insulation.
- One of the biggest challenges facing the submarine optical network is that many parts of the world are still vulnerable to disruptions in service due to lack of redundancy.
- Network architectures use redundant bidirectional links between stations, like roadways and water distribution systems, to prevent loss of use in the event that the signal
from a link or station is lost.
- These so-called “self-healing” rings will loop traffic through operational parts of the ring when the shortest link is disrupted.
Natural causes :
- Natural disasters such as mudslides and typhoons are also a threat to undersea fiber.
- A magnitude-7 earthquake in Taiwan on 26 December 2006 damaged eight submarine
cables, catastrophically cutting off communication to Hong Kong, South East Asia, and China.
- Because Taiwan is located in a central point in Asia’s underwater network, a large population of cables is concentrated in the middle of a major seismic belt.
- The magnitude-9 earthquake and resulting tsunami in March 2011 off the coast of Japan that savaged the Fukushima nuclear power plant also damaged about half of the existing transpacific cables.
The strategic importance of Submarine cables:
- Submarine cables are the backbone of the international telecommunications network.
- Almost 100% of transoceanic Internet traffic is sent via submarine cable.
- The submarine cable network is designed to be resilient, however, faults can disrupt activities we take for granted – banking, airline bookings, internet shopping, education,
health, tourism, defense, and of course, our communication with one another.
- Many Governments now recognize the strategic value of submarine cables and are taking stronger measures to help protect them.
What Google says about its earthquake detection system:
Millions of kilometers of fiber optic networks already span the globe, operated by government, telecommunications providers, and technology companies, including Google.
“By collaborating with the global subsea cable community, we may be able to improve the world’s ability to detect and research seismic activity around the world,” Google said.