10th Asian Regional Conference of IAEG (2015)

Why Japan and Italy Have the Severest Geohazards?
Zhong-qi Quentin YUE (1)(1) Department of Civil Engineering, The University of Hong Kong, Hong Kong, P.R. China
E-mail: yueqzq@hku.hk
Abstract
Why Japan and Italy have the severest geohazards? For many years, various
researchers have tried to give various answers to this question. This paper presents a new
hypothesis to answer the question. The hypothesis is that a thin spherical methane gas CH4
layer exists between the crust and mantle. This gas-sphere layer separates and protects thecold crust rocks and the hot mantle and core materials. The methane gas is produced by the
mantle and core materials and is stored by the spherical trap of the compressive lower crustrock. Because of various deep crustal faults in some special regions including Japan and
Italy, the gas mass of extremely high density and pressure can escape its deep traps andflow to the shallow crustal ground, which causes the severest geohazards including volcano,earthquake, tsunami, land subsidence, ground faulting, and landslide in these regions. The
methane gas can provide both the mechanical energy and the chemical energy to make thegeohazards. In particular, this paper examines the gas cause of active volcanos that arepresent in the ground surface and upper crustal rocks. The volcano cone-shaped mountain isused to estimate the gas chamber volume below the cone-shaped mountain because thevolcano cone rocks come from the rocks originally infilling the gas chamber. The chemical
reaction of the methane gas with the crustal rocks surrounding the chamber produces newgases, lavas and ashes.

Keywords: Crust, mantle, earthquake, volcano, tsunami, landslide, methane gas, gas-sphere1.

The question

A damaging earthquake suddenly releases a large
to extremely large amount of kinetic energy over areaof hundreds kilometer long and ten kilometer wide in
the Earth's crust and on ground surface within a few
tens to two hundreds seconds. However, such kinetic
actions in the Earth's crustal rocks cannot be
pre-known or predicted by people at few months,
weeks, days, hours, minutes, and/or seconds before
they happen. Similarly, a volcano eruption usually
can explode a tremendous amount of compressed
gases, fire, lightening, dusts and rock debris overmany hours and days. These gases include steam
water H2O and carbon dioxide CO2. However, suchmassive eruption in the upper crustal rocks also
cannot be accurately predicted by people.
Why do we have the problem?

People in some regions on the Earth’s crust such
as Japan and Italy have always been suffering theseverest geohazards. They include earthquake,
volcano, tsunami, land subsidence, ground faulting,sinkholes, landslides and debris flows. Thesegeohazards show that their crusts are not stable. Why
are these special regions of the Earth’s crust always
not stable? Why do the severest geohazards havebeen always occurred in these special regions?
For many years, various researchers have tried togive various answers or hypotheses to explain
questions and interpret the geohazards phenomena.
The most widely accepted hypothesis is the plate
tectonics theory which points out these special
regions are located on the active boundaries of major
tectonic plates.
But, these existing hypotheses and/or theories
sometimes cannot be used to resolve thesegeohazards problems. For example, it has been aconsensus that our human beings are still incapable topredict the next damaging earthquakes and/or next
damaging volcano eruptions.

2.

My answer

My answer to the question is that our humanbeings still do not know the existence of a thin
spherical methane gas layer (or a highly compressedgas-sphere) as the interface gap material between thecrust and the mantle.

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10th Asian Regional Conference of IAEG (2015)

For many years, people have believed that the
Earth is a sphere with the radius of 6380 km. Its
surface is covered by the crustal rocks. Beneath thecrust, it has another three main spherical layers. They
are the mantle, the outer core and the inner core. The
mantle and core materials have extremely hightemperature, pressure and density. The outer corematerials are in the state of liquid. The inner coreand mantle materials are mainly in the state of solidwith extremely high density and pressure. The innercore is believed to generate the Earth’s magnetic field.
The radial depth boundaries between crust and mantle,
between mantle and outer core, and between outer
core and inner core are respectively at about 30 km,
2889 km, and 5153 km depth from the ground surface.
On the other hand, people have classified four greatearth realms forming the upper portion of the Earthand outside the crustal rocks. They are theatmosphere, the hydrosphere, the lithosphere and thebiosphere.

brief introduction of this thin highly compressedgas-spherical layer and uses it to explain the cause
and mechanism of volcanoes.

Fig. 2 Idealized sketch for the lower crust to form acomplete spherical trap due to inward gravity bodyforce to seal and keep the gas from the mantle andcore
3.

The Gas-sphere

3.1 Gas generation in mantle and cores andoutward migration
The mantle and core materials are substantiallydifferent from the crust rocks (Figs. 1 and 2). They
have extremely high temperature, pressure anddensity. The mantle rocks may be partially melted.
The upper mantle temperature can be about 1300 °C
to 2000 °C. At the core-mantle boundary, thetemperature can be 4000 °C. The deeper the depth is,
the higher the temperature, pressure and density are.
The facts, phenomena and laws about the mantle andcores are extremely limited or rare.
Therefore, I make the assumption that the mantle
and core materials (minerals) can have chemical
reactions due to the high temperature and pressure
and the chemical reactions would generate heat andcan produce mainly methane gas CH4 and few othergases including Hydrogen gas H2, Helium gas He,
and Argon gas Ar. Accordingly the following
processes and results can be induced.
The generated gases must be much lighter than
the general materials forming the core and mantle,
under the same surrounding high pressure andtemperature in the interior of mantle and the core.
They have to migrate and flow outward and in the
opposite direction of the inward gravitation to upper
lower pressure zone, according to the second law ofthermodynamics (Fig. 1). Because of the decrease in
their surrounding pressures, the outward migratinggases would expand and absorb heat from the coreFig. 1 Idealized sketch for gas generation in the
mantle and core of the Earth and outward migration
to the thin spherical gas layer beneath the crust
Since 1979, the author has studied and examined
many aspects of geology, geophysics, geochemics,
geomechanics, geotechnics, seismology, appliedmathematics and mechanics. Since 2008, the author
has found by induction that there is a thin sphericalgas layer between the crust and the mantle of the
Earth (Yue, 2008a, b; 2009; 2010; 2011a, b; 2012;2013a, b, c, d; 2014). This highly compressedgas-spherical layer has high density and pressure andseparates and protects the crust and the mantle. Thisgas layer is the main source for ensuring the entire
crust to be stable for the majority of time and/or forcausing the crust unstable sometimes and locally.
This hypothesis can logically and systematicallyexplain and interpret many phenomena of the Earthobserved by people on the ground. This paper gives a2

10th Asian Regional Conference of IAEG (2015)

and mantle materials, which may balance thetemperatures there.

up spherical crust rocks and to balance the crust rockweight. It is also an ideal insulation layer to preventthe crust rock from melting by the hot mantle
materials and also to prevent the heat of the mantle
and cores from leaking into the crust rocks and theatmosphere. As a result, the mantle and cores cankeep their hot temperatures for millions to billions
years.
It is estimated that the methane gas mass is about
10 to 240 times of the mass of the atmosphere and isequal to a mass of 5×1019 kg to 125×1019 kg.

3.2 The lower crust rock as a spherical trap
On the other hand, the gravitation toward to thecenter of the Earth always acts as a body force on thecrust rock and the gas, and forces them to move anddeform along the radial inward direction of the Earth.
Similar to a beam or an arch in bending, the lower
crust rock would be always in compression bothalong the radial direction and the lateral hoop
direction. The upper crust rock can be in compression
along the radial direction but in tension along thelateral hoop direction. The lower crust rock mass
must be in a state of extremely tight and compact
because the compressive principle stresses can be 300
MPa to 600 MPa. Its voids in the solid rocks must bevery tiny, little and/or zero. Therefore, it becomes anextremely impermeable solid rock geo-spherical layerand seals the highly compressed gas. It forms aspherical trap and prevents the seeping out of the gas
generated in and migrated from the mantle and core(Fig. 2).

4.

Phenomena of the Gas-sphere

Many phenomena and facts observed by people
on the ground of the Earth can be consistently andlogically explained and interpreted and/or predictedwith the cause of this thin gas-spherical layer forming
the gap seam between the spherical crust and thespherical mantle. These phenomena include
earthquake, volcano, tsunami, huge landsides, gas/oil
in upper crust rock mass, atmospheric air, fresh
water/seawater, land subsidence, continental drift,
ground rupture, weather and atmospheric changes
after earthquake, the Moho discontinuity, continental
rifts-subsidence basin, deep faults, continental plains,ocean basins, gravity anomaly and Bouguer anomaly,
earth tide or body tide, mantle surface waves, freeoscillations of the Earth, seismic waves, earth
expansion
and/orcontraction,
geosyncline,
uniformitarianism and catastrophism, and evolutionof life.
As an example, the phenomenon of present
volcanos is given and discussed in the ensuing.

3.3 The thin highly compressed gas-sphere
Consequently, the outward and upwardmigrations and flows of the gases produced in thecore and mantle would be blocked, contained and
impeded by the impermeable spherical trap of thelower crust solid rocks with high compressive
stresses. The gases would be accumulated and stored
beneath the lower crust rock spherical trap. With time,
more and more gases would be accumulated andstored beneath the spherical trap. The gases would
separate the bottom of the lower crust rock with the
top hot mantle materials.
With time, the gases eventually form a thin
spherical gas layer separating the crust rocks and the
hot mantle materials (Figs. 1 and 2). The gases are
dominantly the methane gas CH4. The gases in thethin spherical layer could have an extremely highdensity of from 1.3 kg/m3 to 2.0 kg/m3, an extremely
high pressure of 300 to 500 MPa.
Its temperatures immediately beneath the crustrock and immediately above the mantle respectively
are about 300 °C and about 700 °C. Such temperature
difference along the radial depth causes the dense gas
to have electric voltage/charges due to thethermoelectric effect. So, it can have relatively highconductivity. Its thickness is about several hundred
meters beneath oceanic crust to a few kilometersbeneath mountainous plateaus of elevations inthousand meters above the sea level. The
gas-spherical layer beneath the Tibetan Plateau is the
thickest region. This thin gas-spherical layer is thegap material forming the Moho discontinuity.
Besides, this thin gas-spherical layer is an ideal
foundation footing to flexibly support and uplift theFig. 3 Sketch showing the cause and mechanism of
volcano in upper crustal rocks by the gas migrated
from the deep gas-sphere via deep faults
5.

The Gas Cause of Volcanos

5.1 The gas cause
As shown in Figure 3, a volcano usually forms acone-shape mountain and has a crater with verticalpipe conduit to allow hot lava, volcanic ash and gases
to escape or erupt from its underground chamber.
The chamber locates several kilometers below theground rock strata or rock mass in the upper crust.
For many years, people have believed that the3

10th Asian Regional Conference of IAEG (2015)chamber contains magma that comes and migrates
directly from the mantle via various channels such as
faults or ruptures in deep crust rocks. In fact, thismechanism is mechanically impossible. Because of
the extremely high compressive stresses along thelateral hoop directions and vertical directions at thelower crustal rocks, the mantle magma cannot flow
outward passing through this compressive lower
crustal rock layer.
The author has found and shown that the present
volcanos on and in the upper crustal rocks are causedby the high compressed and dense gases escapedfrom the thin spherical gas layer. The escaped gas
mainly CH4 are further trapped in the upper crustalrock masses. They make chemical reactions with thesurrounding rocks in the chamber. The chemical
reactions are the types of reduction anddecomposition. The reactions change the gas
chemical compounds into steam water gas H2O, CO2,
H2S, SO2 and others. For example, the following
chemical reaction can take place.
CH4 + 2O2 = CO2 + 2H2O + Heat

the upward expansion pressure from the highly
compressed gas mass in the chamber and theoverburden loading of the cone-shape rock mountain.
Then, a huge amount of highly compressed gas masscan erupt powerfully and cause the chamber roof
rock to collapse completely. The rock forming thecone-shape mountain can then fall into the cavity
space of the gas chamber underneath. A lake can beformed at the previous place of the cone-shaped
mountain.
The gas chamber volume can be estimated withthe following equation.
Vcavity(t) = Vcone(t) + Vlake(t) + Vash(t)(2)

where Vcavity = the gas chamber volume, Vcone = thecone-shaped rock mount volume, Vlake = lake volume,
Vash = ash volume.
It is noted that there are more than 1500 active
volcanoes on the Earth at present. Each volcano has agas chamber with ongoing chemical reactions. They
are mainly located in deep fault zones andcrustal-plate contact zones including these along the
Pacific Ring of Fire. On the other hand, nearby
those active volcanos, there are usually many hugenatural gas reservoir fields and strong earthquake.

(1)

The oxygen in the above chemical reaction comesfrom the surrounding crustal rocks. So, the otherproduct of lava generally has a less amount ofoxygen than that of the surrounding crustal rocks.
Metal liquids can also be generated and can deposit
in ruptures and form metal ore veins in thesurrounding rock mass. The gas-rock chemical
reactions also produce heat. The gas expansion andpenetration power and the heat further break andcrack the surrounding rock mass and make them intolavas, fragments, ashes or bombs.

5.3 The Lake Toba
Fig. 4 shows the Lake Toba in North Sumatra,Indonesia. It is the result of a super-volcanic eruptionthat occurred 69,000–77,000 years ago, a massive,
climate-changing event. The lake has a maximum
length 100 km and maximum width 30 km. Its
surface area is 1130 km2. Its maximum depth is 505
m. its present water volume is 240 km3 and surface
elevation 905 m. Formation mechanism of the Lake
Toba can be described and interpreted below with thegas cause of volcanos as shown in Fig. 3.
Accordingly, the gas chamber volume below theoriginal Toba volcano before its final eruption ismuch greater the present water volume 240 km3.

5.2 The rock volume balance model
During earthquakes, some amount of the methanegas mass in the thin gas-sphere can rupture andescape the trap and rapidly migrate into the upper
crustal rock. It can accumulate and store in the gaschamber within the upper crustal rock. The gas mass
M(t) in the chamber accumulates more & more andhas higher & higher pressure p(t). The gas can makechemical reactions with the surrounding rocks, whichcause the chamber cavity space V(t) larger & larger,
and the original roof rock thickness hroof(t) thinner &thinner.
With time, some amounts of highly compressedgas can erupt and carry the broken and/or alternatedsurrounding rocks and molten rocks (lavas) out of theground. The rock debris and lavas accumulate on the
ground surface and gradually form a cone-shaped
mountain. As a result, the Vcone(t) can become larger
and larger with time and more and more eruptions.
The cone mount height hcone(t) can become higher &higher.
Eventually, the upper roof rock cannot support

Fig. 4 Present topography of Lake Toba in North
Sumatra, Indonesia (after Google Map)4

10th Asian Regional Conference of IAEG (2015)

5.4 Mount Etna Volcano
Fig. 5 shows the Etna Volcano in Zafferana Etna,
Catania, Italy. Using the topography map (Fig. 5a), itscone mountain volume has a volume of 800 km3 (Fig.
5b). Using equation (2), it can be estimated that thegas chamber space volumes for the Etna Volcano is
greater than or equal to 800 km3.

and impeded by the dense solid rocks of the lower
crust with extremely high compressive stresses. The
lower crust rock functions and forms a spherical trap
for the storage and accumulation of the gases fromcore and mantle. The gases then form a thin sphericallayer separating and protecting the crust rocks and the
hot mantle-core materials.
Further leaking and migrating and expanding of
the highly compressed and dense gas along deep
faults and orogens into the middle and upper rockcrustal rock masses causes geo-disasters such as
earthquake, volcano, landslides and tsunami, the oiland gas fields, the air in the atmosphere, as well as
the water on the ground and in the oceans.
In particular, the gas cause of the present active
volcanos has been examined with the three examplesof the Lake Toba, the Etna volcano and the Fuji
volcano.
In other words, there are huge amounts ofmethane gas CH4 mass within and beneath the crustrocks of Japan and Italy. This natural resource has notbeen known and used by people in Japan and Italy.

Fig. 5 Present topography of Etna Volcano after
Google Map (a) and the estimation of the volume of
the cone-shape mountain (b)5.5 Mount Fuji Volcano
Fig. 6 shows the Fuji Volcano in Fujinomiya,
Shizuoka, Japan. Using the topography map (Fig. 6a),
its cone mountain volume has a volume of 900 km3(Fig. 6b). Using equation (2), it can be estimated thatthe gas chamber space volumes for the Fuji Volcano
is greater than or equal to 900 km3.

Acknowledgements
The author would like to thank many friends andcolleagues for their invaluable advices, assistances,discussions, information, data and supports during his
independent investigations of the nature ofearthquakes and the Earth system.
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Fig. 6 Present topography of Etna Volcano in
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Conclusions

In this paper, the author has given his answer tothe question why Japan and Italy Have the Severest
Geohazards? His answer is that there is a thin andhighly compressed gas spherical layer beneath thespherical crust rocks and above the spherical hot
mantle materials. The one and only one assumption isthat the general materials in the core and mantle of
the Earth have extremely high temperature andpressure and density. Accordingly, the core andmantle materials can have chemical reactions
producing the methane gas CH4. The gases would
migrate upward to the lower pressure zone according
the second law of thermodynamics above the hot
mantle materials.
Eventually, they would be blocked and contained

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