Granada trembles again during the night: six new earthquakes shake the province

After an earthquake in Spain, the National Geographic Institute (IGN), through the National Seismic Network, applies a set of technical procedures to detect the earthquake, estimate its basic parameters, and continuously review them until the most accurate values possible are established. These parameters feed the official seismic catalog, the “IGN Earthquakes” viewers, and the information received by Civil Protection and other administrations.

1. Automatic detection and initial location

The process starts at the very moment of the tremor:

• The National Seismic Network records the movement at its stations and generates a preliminary automatic solution (origin time, epicenter, depth, and magnitude) based on the signals received.
• This information is almost immediately uploaded to the IGN public viewer and the official earthquake catalog, which allows filtering by area, magnitude, dates, intensity, and depth, as described in the informative piece about CNIG tools and “IGN Earthquakes” on the Electronic Administration Portal (CNIG applications).
• This initial record is explicitly provisional: recent coverages remind that the IGN warns that “all these parameters are subject to modifications as seismic analysis continues” and that “the information disseminated immediately after an earthquake is provisional.”

2. Review of magnitude, depth, and epicenter

From there, a finer analysis phase opens, in which data may change:

• The National Seismic Network progressively incorporates signals from all available stations, not only from the IGN but also from collaborating networks (for example, stations of the Andalusian Institute of Geophysics, as explained in the report on the Granada seismic series: “Earthquakes in Granada, in charts”).
• With these additional records, the location (epicenter coordinates), depth, and magnitude are recalculated repeatedly. It is common that, in the first hours, depth or magnitude change: for example, an earthquake initially reported as magnitude 5 has been revised to a moment magnitude Mw 4.8, or the depth is adjusted from several kilometers to a practically superficial value.
• The reference locality used to describe the epicenter may also be reviewed, since “the National Seismic Network reviews the signals received by its stations and may subsequently modify the magnitude, depth, coordinates, or even the locality used to describe the epicenter” (“Earthquake near me: check the IGN map”).
• The IGN notes this dynamic nature by indicating in its records that recent earthquake parameters “remain subject to review.”

3. Continuous updating of the catalog and viewers

All this work is reflected in official products:

• The seismic catalog is continuously updated “as new data arrive” and parameters are recalculated; articles about the Granada series emphasize that “the IGN catalog is continuously updated and reviewed” and that informative pieces “must remain alive and be modified when a new significant movement appears.”
• The latest earthquakes viewer (“IGN Earthquakes”) shows these adjustments in near real-time: magnitude, depth, or epicenter position change when a revision is published, and successive aftershocks located by the Network are added.
• In relevant episodes, the IGN may highlight the moment magnitude (Mw) as the definitive reference value against initial estimates based on other scales.

4. Seismic sequences and deployment of additional instrumentation

If the earthquake is part of a significant series, the procedure includes instrumental reinforcement:

• Besides a dense network of permanent stations, the IGN can deploy portable seismic stations in the epicentral area to improve data quality and location precision, as described in recent coverages about Granada.
• These new records allow better characterization of the fault geometry, aftershock distribution, and temporal evolution of the sequence, which is reflected in the maps and charts subsequently disseminated.

5. Integration into emergency management and national plans

The IGN procedures are not limited to the technical part but are embedded in civil protection planning:

• The IGN is the official reference to “determine where an earthquake has occurred, its magnitude, depth, and characteristics,” and this data is the basis for autonomous communities to decide on activating special seismic risk plans, as covered in the competency analysis on “Who does what in an earthquake” (earthquakes in Spain: competencies).
• The National Plan for Seismic, Volcanological, and Other Geophysical Phenomena Surveillance, approved by the Government in 2025 and developed by the IGN, aims to strengthen surveillance networks, improve coordination among administrations, and develop new tools (including artificial intelligence) to enhance early warnings (Ministry of Transport note).

Overall, it can be said that the IGN procedure after an earthquake combines rapid detection and immediate dissemination of provisional data with a systematic and continuous review of seismic parameters, permanent updating of its catalogs and viewers, and coordination with civil protection systems so that emergency management decisions are always based on the best available information.

The Junta de Andalucía exercises very broad competencies in civil protection, covering regulation, planning, and execution of emergency measures, including seismic emergency management, in coordination with the State and municipalities. These functions are framed within the Statute of Autonomy, the state Law 17/2015 of the National Civil Protection System, and, at the Andalusian level, Law 2/2002 on Emergency Management in Andalusia, amended by Law 2/2023.

Basic competency framework

Article 66.1 of Organic Law 2/2007, reforming the Statute of Autonomy for Andalusia, grants the Autonomous Community exclusive competence in civil protection, which includes:

• Regulation of the matter.
• Planning and execution of measures related to emergencies and civil safety.
• Direction and coordination of civil protection services, including fire prevention and extinction services, respecting state competencies in public security.

These competencies are exercised within the general framework set by Law 17/2015, of July 9, of the National Civil Protection System, which defines the distribution of functions among the State, autonomous communities, and local entities, especially in inter-administrative coordination and emergencies of national interest.

Andalusian emergency management law

Law 2/2002, of November 11, on Emergency Management in Andalusia, establishes an Andalusian civil protection system for all emergencies not declared of national interest. Among the functions assigned to the Junta de Andalucía and the competent civil protection ministry are:

• Promote risk forecasting and reduction, including the development of risk maps within the Autonomous Community.
• Establish and approve emergency planning, through:
  • Andalusian Territorial Emergency Plan (PTEAnd), which defines the regional response to situations of serious risk, catastrophe, or public calamity.
  • Special plans for specific risks (such as seismic risk, tsunamis, etc.), developed according to basic state guidelines.
  • Specific plans for risks of special significance in Andalusia.
• Organization and coordination of the response system, through the Andalusian Emergency Coordination Center and the integrated emergency and urgency system (including 112).
• Coordination with operational services (firefighters, security forces, health services, etc.) and civil protection volunteers.
• Regulation and coordination of fire prevention, extinction, and rescue services, strengthened by the amendment introduced by Law 2/2023.

Relationship with the State and the National System

Law 17/2015 and the State General Civil Protection Emergency Plan (PLEGEM), approved by Resolution of December 16, 2020, foresee that:

• Autonomous communities, including Andalusia, are responsible for ordinary emergencies in their territory, with their own territorial and special plans.
• In emergencies of national interest, direction passes to the Ministry of the Interior, integrating Andalusian emergency coordination bodies into the state scheme, with mutual collaboration duties.
• The State Civil Protection Plan for Seismic Risk (Resolution of March 29, 2010) acts as the master plan and is operationally supported by autonomous special seismic risk plans and, failing that, by the territorial plans of the autonomous communities.

Role of municipalities and vertical coordination

Law 2/2002 assigns Andalusian municipalities a general capacity for planning and action in civil protection:

• Develop, approve, and implement their Municipal Emergency Plan.
• Maintain the catalog of mobilizable resources in their territory.
• Create the municipal civil protection structure and, if applicable, the Local Operational Coordination Center.
• Promote prevention and public information programs.

The Junta de Andalucía, through the competent ministry, endorses municipal plans and ensures their coherence with the Andalusian Territorial Emergency Plan and special plans (including seismic), thus ensuring a continuous planning chain from local to autonomous levels and, through the National Civil Protection System, to the state and even international levels.

In summary, the Junta de Andalucía has full competencies in regulation, planning, operational coordination, and resource provision in civil protection, including seismic emergency management, within a multilevel system where state, autonomous, and municipal plans are articulated and clear mechanisms for support and leadership assumption are defined depending on the severity and national interest of the emergency.

In Spain, emergency management and protocols for action in the event of earthquakes rely on a state civil protection regulatory framework and seismic-resistant technical standards for buildings and infrastructures. On this common basis, autonomous communities and local entities develop their own special and territorial civil protection plans.

1. General civil protection framework

The core regulation is Law 17/2015, of July 9, of the National Civil Protection System (text in BOE). This law:

• Establishes civil protection as a public service integrated into public security and National Security policy.
• Defines the National Civil Protection System, its coordination bodies (for example, the National Civil Protection Council), and the emergency cycle: forecasting, prevention, planning, intervention, recovery, and general coordination.
• Establishes citizens' rights (information about risks, participation in planning, etc.) and duties of collaboration in emergencies.
• Provides for the development of civil protection plans of different scopes (state, autonomous, and local) and regulates planning for specific risks.

This law updates and replaces the previous framework given by Law 2/1985, on Civil Protection, and relies on prior basic regulatory instruments that remain references, such as:

• The Basic Civil Protection Standard, approved by Royal Decree 407/1992, of April 24, which sets the general structure of planning (territorial plans and special plans by risks, including seismic).
• The Basic Self-Protection Standard, approved by Royal Decree 393/2007, of March 23, mentioned in Law 17/2015 as a key piece for centers and risk activities to have their own self-protection plans.

2. Specific planning for seismic risk

Within this general framework, earthquake planning is articulated through a basic directive and special plans:

• The Basic Directive for Civil Protection Planning against Seismic Risk, approved by Council of Ministers Agreement and published by the Resolution of May 5, 1995 of the State Secretariat of the Interior (text in BOE).
  • Establishes the minimum requirements that special civil protection plans against seismic risk must meet.
  • Defines the organizational structure, operational criteria, intervention measures, and coordination mechanisms among Administrations.
  • Identifies seismic hazard areas in Spain, based on the seismic hazard map of the National Geographic Institute, and determines in which autonomous communities special plans must exist.
• The State Civil Protection Plan against Seismic Risk, approved by Council of Ministers Agreement of March 26, 2010 and published by Resolution of March 29, 2010 of the Undersecretariat (text in BOE).
  • Specifies the organization and procedures for the use of State resources and services in emergencies due to earthquakes of national interest.
  • Regulates the support mechanisms of the State to autonomous community plans when they require it or lack sufficient response capacity.
  • Details severity levels, warning systems, operational direction and coordination, and the role of specialized units such as the Military Emergency Unit.

On this state basis, each autonomous community must approve its Special Civil Protection Plan against Seismic Risk, and autonomous plans may in turn deploy local action plans. All must comply with the Basic Directive and the State Plan to guarantee a “minimum national model” and interoperability of protocols.

3. Seismic-resistant building and infrastructure regulations

Damage reduction in an earthquake depends not only on emergency management but also on construction design. At the state level, notable regulations include:

• Royal Decree 997/2002, of September 27, approving the Seismic-Resistant Construction Standard: General Part and Building (NCSE-02) (text in BOE).
  • Applies to all building-related construction projects and works and, subsidiarily, to other constructions where no specific regulation exists.
  • Sets technical conditions so structures behave safely against seismic actions, avoiding serious consequences for life and health, reducing economic losses, and facilitating continuity of basic services.
• Royal Decree 637/2007, of May 18, approving the Seismic-Resistant Construction Standard: Bridges (NCSP-07) (text in BOE).
  • Specifically regulates projects and works for new bridges on the state road network and the general interest railway network.
  • Considers specific characteristics of bridges (vibration frequency, construction process, service life, etc.) and their role as critical transport infrastructures in a seismic event.

Altogether, these regulations form the basic legal framework for emergency management and protocols for action against earthquakes in Spain, combining multilevel civil protection planning and seismic-resistant technical design requirements.