Earthquake in Tangshan

The earth cycles identified are: plate tectonics are plates into which the earths outer shell is divided into which constantly move towards or away from each other, rocks which are natural solid aggregates found on the earth’s surface and water cycle is the continuous movement of water on the earth’s surface.

Describe in one sentence any interaction that occurs between these cycles.

Water present in underground rocks causes changes in the rock’s pore pressure when it freezes and thaws while the plate tectonics constantly move causing rocks to break along fault lines when they move towards each other.

Describe briefly how these influence you impact/hazard.

When plate tectonics move towards each other, they cause rocks to break along the fault lines causing friction and shaking which result into earthquakes (Hirschman, 2018). Freezing and thawing of water can also create fault line which trigger earthquakes.

Section 2:

Describe in one sentence the Earth systems you identified in your first Milestone.

The biosphere is the sphere of the earth that integrates all living creatures and their relationships while the hydrosphere is the sphere of the earth that holds the liquid water component and human impact are man-made activities that directly or indirectly cause changes on the earth.

Describe in one sentence any interaction that occurs between these systems.

The hydrosphere provides water that sustain all life on the biosphere and human impact causes changes to both the hydrosphere and biosphere through human activities like mining and manufacturing.

Describe briefly how these influence your impact/hazard.

Human activities that cause vibrations like mining and blasting create fault lines in rocks thus triggering earthquakes when these rocks break along the fault line created. During an earthquake, the ocean bed may shift thus causing tsunamis which enhances the impact of earthquakes.

Section 3:

Describe briefly any human interaction that could influence your impact/hazard.

Human interactions like coal mining in Tangshan weakens rocks and cause fault lines along which rocks break and trigger earthquakes. Construction of dams also apply undue influence of rock and induce earthquakes.

Describe briefly why humans have chosen to live in the location of your impact/hazard.

Humans still live in Tangshan despite the earthquake since they work in the coal mines and the various industries in the city to support their livelihoods

Describe briefly how human presence has increased the risk of damage/loss of life.

The high population in Tangshan increases the number of lives lost and properties destroyed during an earthquake due to their vulnerability in an earthquake zone (Li et al., 2016). Further, the industries also mean more damage of properties occurs during an earthquake.

Add a graph that illustrates any changes to the population for your impact/hazard location after the event occurred.

Figure 1: A grap illustrating changes to Tangshan population after the 1976 earthquake (Li et al., 2016).

Section 4:

List any geological/geographic features that may influence your impact/hazard.

Geographical features that may influence earthquakes are;

i) Areas geographically located in seismic zones which are usually on the plate tectonic boundaries are more prone to earthquakes.

ii) Areas that have several fault lines.

iii) Areas located in soft rocks.

Describe how these features impact your impact/hazard.

Seismic zones experience vibrations as a result of plate tectonics pushing towards each other or moving past each other triggering earthquakes (Hirschman, 2018). Rocks break along fault lines causing earthquakes and as such areas that have several fault lines are more at risk of earthquake. Further, soft rocks easily break and cause earthquakes.

Add a map or illustration of these features.

(Li et al., 2016).

Figure 2: Map Showing Tangshan seismic zones and fault lines.

References

Hirschmann, M. M. (2018). Comparative deep Earth volatile cycles: The case for C recycling from exosphere/mantle fractionation of major (H2O, C, N) volatiles and from H2O/Ce, CO2/Ba, and CO2/Nb exosphere ratios. Earth and Planetary Science Letters, 502, 262-273.

Li, C., Xu, W., Wu, J., & Gao, M. (2016). Using new models to assess probabilistic seismic hazard of the North–South Seismic Zone in China. Natural Hazards, 82(1), 659-681.