Hazards: ELSS

What impacts does this have?

• Damage to roads/infrastructure

• Difficult to receive aid = slow recovery

How can the cryosphere

Example of this?

• East African Rift Valley

• Spans all the way from Ethiopia to Malawi

• Largest, oldest & deepest on Earth.

• Lake Shala, Lake Abaya & Lake Chamo.

• Lakes have no outlet into sea causing high levels of salinity.

How are lahars worsened by water cycle?

• Lahar risk increased with heavy rainfall/monsoon season - lahar is mudflow/saturated volcanic ash.

• Saturated, mobile - travels up to 50km.

Example of this?

• Nevado del Ruiz (1985)

• 23,000 death in Armero - flooding, covered in mud.

• Flooding leads to increased loss of life, injuries, displacement of people.

Volcanoes & avalanches?

• Avalanche risk increased on high altitude volcanoes.

• Greater risk of damage to infrastructure/roads

• Difficult for aid to reach isolated areas.

How does latitude worsen volcanic eruptions?

• Higher latitude = ice/snow covering the crater.

• E.g. Iceland 2010, E-19

• More explosive eruptions

Pyroclastic flows?

• Pyroclastic flows remove vegetation

• E.g. Mt St Helens (1980): removal of vegetation on flanks of volcano, decreased in rates of transpiration/interception - increased surface run-off.

• Less water enters atmosphere was water vapour, more surface run-off/increased flood risk.

How else do pyroclastic flows worsen the water cycle?

• PF entering sea generate tsunami (rare events) increased risk on volcanic island arcs.

• Movement of water from ocean store to land store - increased land flooding.

• E.g. Krakatoa (1886): tsunami 46m high.

• 36,000 deaths caused by Krakatoa tsunami.

How can avalanches on volcanoes make impacts worse?

• Debris avalanche on volcano - blocks outlet of crater lake.

• Increases volume of crater lake store.

• E.g. Mt St Helens (1980): blocks outlet of Toutle River - without outlet, height of lake rose, threatening to breach unstable blockage.

• 1982: pumping station put in place to restrict height of crater lake.

How can earthquakes impact the carbon cycle: geology?

• Uplift of sedimentary rock = geological/lithosphere store, due to shifts in tectonic plates.

• Exposed to chemical weathering = carbonation.

• More CO2 enters atmosphere & hydrosphere.

Landslides impact carbon cycle?

• Landslides occur due to shaking of ground.

• Soil exposed & weathered - releases carbon from soil to atmosphere.

• Less carbon stores in soil & more released into atmosphere.

Landslides impact flows/stores of carbon?

• Landslide move carbon rich sediment into rivers - movement from soil to river (transfer) to oceans.

• 2008: EQ in Wenchuan, China - 200,000 landslides increased carbon transfer from soils to river.

• Thus, carbon transported by rivers into long-term carbon store in oceans.

Tsunamis damaging biosphere?

• Damage to coastal forests (biosphere) due to tsunami.

• e.g. Tohoku EQ, Japan (2011): inundation of tsunami wave removed vegetation (biosphere) & soils (pedosphere) - due to loss of soils reduced recovery rate of vegetation.

• Reduction in carbon store, loss of sequestration via photosynthesis.

How can EQs release carbon from geological reservoirs?

• EQs can cause faulting & release of captured carbon from geological reservoirs (stores).

• Demolition of building & removal of debris following EQ increased embodied carbon - life cycle of carbon for construction & demolition of building.

Example?

• Christchurch EQ, NZ

• 7000 houses & 1400 commercial properties demolished.

• Created 4 million tonnes of building debris.

• Energy costs for removing debris significantly increased carbon emissions - transfer of carbon to atmosphere.

• Environmental reason for improved EQ resilient buildings.

How can volcanic activity impact carbon cycle in geological store?